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1,482,218 commits

Author SHA1 Message Date
Svyatoslav Ryhel
34d8943508 ARM: tegra: transformer: Add support for front camera
Add front camera video path. Aptina MI1040 camera is used on all supported
ASUS Transformers, but only TF201 and TF700T will work since on
TF300T/TG/TL front camera is linked through an additional ISP.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2026-05-29 14:36:14 +02:00
Svyatoslav Ryhel
a5acde8adb ARM: tegra: grouper: Add support for front camera
Add front camera video path.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2026-05-29 14:36:14 +02:00
Ion Agorria
ece4229e45 ARM: tegra: p880: Lower CPU thermal limit
Lower the CPU thermal limit for the LG P880, since its chassis has less
thermal dissipation capability than the P895.

Signed-off-by: Ion Agorria <ion@agorria.com>
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2026-05-29 14:36:12 +02:00
Svyatoslav Ryhel
61cf0112f7 ARM: tegra: lg-x3: Set PMIC's RTC address
LG X3 devices have the PMIC's RTC module located at a non-standard
address. Set the correct address.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2026-05-29 14:36:12 +02:00
Svyatoslav Ryhel
8399055d9f ARM: tegra: lg-x3: Complete video device graph
Add front and rear camera nodes and interlink them with Tegra CSI and VI.
Adjust camera PMIC voltages to better fit requirements and fix the focuser
node.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2026-05-29 14:36:11 +02:00
Aaron Kling
e1215cd6d3 arm64: tegra: Enable SMMU on Tegra194 display controllers
These use a separate SMMU instance compared to everything else currently
enabled for the SoC.

Signed-off-by: Aaron Kling <webgeek1234@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2026-05-29 14:33:29 +02:00
Lad Prabhakar
ebf7f2198a mmc: renesas_sdhi: Add OF entry for RZ/G2E SoC
The RZ/G2E (R8A774C0) SoC was previously handled via the generic
"renesas,rcar-gen3-sdhi" fallback compatible string. However, because
the SDHI IP on RZ/G2E is identical with the R-Car E3 (R8A77990), it
requires the specific quirks and configuration defined in
`of_r8a77990_compatible` rather than the generic Gen3 data.

Add the explicit "renesas,sdhi-r8a774c0" match entry to map it correctly.
Note that the DT binding file renesas,sdhi.yaml does not need an update
as the entry for this SoC is already present.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Ulf Hansson <ulfh@kernel.org>
2026-05-29 14:32:39 +02:00
Lad Prabhakar
5ce500d31a mmc: renesas_sdhi: Add OF entry for RZ/G2N SoC
The RZ/G2N (R8A774B1) SoC was previously handled via the generic
"renesas,rcar-gen3-sdhi" fallback compatible string. However, because
the SDHI IP on RZ/G2N is identical with the R-Car M3-N (R8A77965), it
requires the specific quirks and configuration defined in
`of_r8a77965_compatible` rather than the generic Gen3 data.

Add the explicit "renesas,sdhi-r8a774b1" match entry to map it correctly.
Note that the DT binding file renesas,sdhi.yaml does not need an update
as the entry for this SoC is already present.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Ulf Hansson <ulfh@kernel.org>
2026-05-29 14:32:39 +02:00
Aaron Kling
3b7b80753c Revert "arm64: tegra: Disable ISO SMMU for Tegra194"
This reverts commit ebea268ea5.

Mmu is now being enabled for the display controllers.

Signed-off-by: Aaron Kling <webgeek1234@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2026-05-29 14:32:21 +02:00
Svyatoslav Ryhel
27a58cc1a9 drm/tegra: dsi: Re-add clear enable register if DSI was powered by bootloader
Original commit b22fd0b963 ("drm/tegra: dsi: Clear enable register if
powered by bootloader") was added to address the issue of DSI being in an
unknown state after the bootloader, ensuring correct panel configuration.
This worked fairly well under the assumption that the bootloader had set
up DSI; however, in cases where it did not, the device would hang because
a DSI read was called before the DSI hardware was ready.

Removing this workaround results in the issue described in the original
fix: the panel initialization sequence fails and the panel gets stuck in
an undefined state. This is especially noticeable with command mode panels

In order to properly address this issue, the original workaround is
restored and placed after the DSI hardware is prepared for R/W operations.
This fixes behavior for both cases: where DSI is set by the bootloader and
where DSI is untouched.

I have tested this change on Tegra20 (Motorola Atrix 4G),
Tegra114 (NVIDIA Tegra Note 7 and ASUS Transformer Pad TF701T), and
Tegra124 (Xiaomi Mi Pad) with U-Boot, using both bootloader-initialized
DSI and untouched DSI.

Fixes: b22fd0b963 ("drm/tegra: dsi: Clear enable register if powered by bootloader")
Fixes: 660b299bed ("Revert "drm/tegra: dsi: Clear enable register if powered by bootloader"")
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patch.msgid.link/20260511074538.24563-3-clamor95@gmail.com
2026-05-29 14:29:19 +02:00
Ulf Hansson
7f1634319a mmc: Merge branch fixes into next
Merge the mmc fixes for v7.1-rc[n] into the next branch, to allow them to
get tested together with the mmc changes that are targeted for the next
release.

Signed-off-by: Ulf Hansson <ulfh@kernel.org>
2026-05-29 14:29:16 +02:00
Svyatoslav Ryhel
39e535c95f drm/tegra: dsi: Add support for Tegra20/Tegra30
Tegra20 and Tegra30 are fully compatible with existing Tegra DSI driver
apart from clock configuration and pad calibration which are addressed
by this patch.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patch.msgid.link/20260511074538.24563-2-clamor95@gmail.com
2026-05-29 14:28:53 +02:00
Lad Prabhakar
f48ee49726 mmc: renesas_sdhi: Add OF entry for RZ/G2H SoC
The RZ/G2H (R8A774E1) SoC was previously handled via the generic
"renesas,rcar-gen3-sdhi" fallback compatible string. However, because
the SDHI IP on RZ/G2H is identical with the R-Car H3-N (R8A77951), it
requires the specific quirks and configuration defined in
`of_r8a7795_compatible` rather than the generic Gen3 data.

Add the explicit "renesas,sdhi-r8a774e1" match entry to map it correctly.
Note that the DT binding file renesas,sdhi.yaml does not need an update
as the entry for this SoC is already present.

Fixes: 3194134288 ("arm64: dts: renesas: r8a774e1: Add SDHI nodes")
Cc: stable@vger.kernel.org
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Ulf Hansson <ulfh@kernel.org>
2026-05-29 14:25:50 +02:00
Abel Vesa
cb4b9aeb3a dt-bindings: mmc: sdhci-msm: Add Eliza compatible
Document the compatible string for the SDHCI controller on the
Eliza platform.

Signed-off-by: Abel Vesa <abel.vesa@oss.qualcomm.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Ulf Hansson <ulfh@kernel.org>
2026-05-29 14:20:34 +02:00
Osama Abdelkader
d04e0151d3 mmc: davinci: fix mmc_add_host order in probe
mmc_add_host() makes the host visible to the MMC core. Register the
interrupt handlers and advertise MMC_CAP_SDIO_IRQ before that, so the
core cannot start using the host before IRQ handling is set up.

Signed-off-by: Osama Abdelkader <osama.abdelkader@gmail.com>
Signed-off-by: Ulf Hansson <ulfh@kernel.org>
2026-05-29 14:15:58 +02:00
Huan He
8d4ae34e99 mmc: sdhci-of-dwcmshc: Fix reset, clk, and SDIO support for Eswin EIC7700
The EIC7700 code in sdhci-of-dwcmshc uses host->mmc->caps2 to select
different configuration paths for different card types. The current logic
distinguishes eMMC and SD, but does not handle SDIO separately.

Update the EIC7700 card-type checks so that eMMC, SD and SDIO are
distinguished explicitly.

Switch the reset path to dwcmshc_reset() so that pending interrupt state
is cleared consistently, and use sdhci_enable_clk() so the clock enable
sequence follows the standard SDHCI flow.

Fixes: 32b2633219 ("mmc: sdhci-of-dwcmshc: Add support for Eswin EIC7700")
Signed-off-by: Huan He <hehuan1@eswincomputing.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulfh@kernel.org>
2026-05-29 14:13:58 +02:00
Tudor Ambarus
7fe40c32a3 firmware: samsung: acpm: Fix infinite loop on sequence number exhaustion
Sashiko identified a possible infinite loop [1].

ACPM IPC sequence numbers are tracked via a 64-bit bitmap. Previously,
acpm_prepare_xfer() used a do...while loop to search for a free
sequence number.

If all 63 available sequence numbers are leaked due to transient
hardware timeouts or mailbox failures, the bitmap becomes full.
The next call to acpm_prepare_xfer() would enter an infinite loop.

Fix this by utilizing the kernel's optimized bitmap search functions
(find_next_zero_bit / find_first_zero_bit). If the pool is completely
exhausted, log the failure and return -EBUSY to allow the kernel to
fail gracefully instead of hanging.

Furthermore, drop the allocation loop entirely. Because
acpm_prepare_xfer() is strictly called under the 'tx_lock' mutex,
sequence number allocations are perfectly serialized. If
find_next_zero_bit() locates a free bit, a single
test_and_set_bit_lock() is mathematically guaranteed to succeed.

To enforce this locking invariant, wrap the allocation in a
WARN_ON_ONCE. If the atomic set fails, it indicates the driver's
mutex serialization is fundamentally broken. The warning generates a
stack trace for debugging, while returning -EIO immediately aborts the
transfer to prevent silent payload corruption.

Cc: stable@vger.kernel.org
Fixes: a88927b534 ("firmware: add Exynos ACPM protocol driver")
Closes: https://sashiko.dev/#/patchset/20260420-acpm-tmu-v3-0-3dc8e93f0b26%40linaro.org [1]
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://patch.msgid.link/20260505-acpm-fixes-sashiko-reports-v5-7-43b5ee7f1674@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
2026-05-29 14:11:23 +02:00
Tudor Ambarus
bf296f83a3 firmware: samsung: acpm: Fix missing LKMM barriers in sequence allocator
Sashiko identified memory ordering races in [1].

The ACPM driver uses a globally shared 'bitmap_seqnum' to track
available sequence numbers. Even though threads now strictly free their
own sequence numbers, the allocation and freeing of these bits across
concurrent threads are effectively lockless operations and require
explicit LKMM memory barriers.

Previously, the driver used plain bitwise operators (test_bit, set_bit,
clear_bit), which lack ordering guarantees. This creates two race
conditions on weakly ordered architectures like ARM64:

1. Polling Release Violation: The polling thread copies its payload and
   calls clear_bit(). Without a release barrier, the CPU can reorder
   the memory operations, making the cleared bit globally visible
   before the payload reads have fully completed.
2. TX Acquire Violation: The TX thread loops on test_bit(), calls
   set_bit(), and then wipes the payload buffer via memset(). Without
   an acquire barrier, the CPU can speculatively execute the memset()
   before the bit is safely and formally claimed.

If these reorderings overlap, a new TX thread can claim the sequence
number and overwrite the buffer while the original polling thread is
still actively reading from it.

Fix this by upgrading the bitwise operators. Wrap the TX allocation in
test_and_set_bit_lock() to establish formal LKMM Acquire semantics, and
pair it with clear_bit_unlock() in the polling path to enforce Release
semantics.

Cc: stable@vger.kernel.org
Fixes: a88927b534 ("firmware: add Exynos ACPM protocol driver")
Closes: https://sashiko.dev/#/patchset/20260423-acpm-fixes-sashiko-reports-v1-0-2217b790925e%40linaro.org [1]
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://patch.msgid.link/20260505-acpm-fixes-sashiko-reports-v5-6-43b5ee7f1674@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
2026-05-29 14:11:22 +02:00
Tudor Ambarus
c889b14647 firmware: samsung: acpm: Fix false timeouts and Use-After-Free in polling
Sashiko identified severe races in the polling state machine [1].

In the ACPM driver's polling mode, threads waited for responses by
monitoring the globally shared 'bitmap_seqnum'. This caused false
timeouts because if a thread processed its response and freed the
sequence number, a concurrent TX thread could immediately reallocate
it before the polling thread woke up.

Additionally, the driver suffered from a cross-thread Use-After-Free
(UAF) preemption race. Previously, acpm_get_rx() cleared the sequence
number of whichever RX message it drained from the hardware queue. This
meant Thread A could globally free Thread B's sequence slot while
Thread B was asleep. A new Thread C could then steal the slot,
overwrite the buffer, and leave Thread B to wake up to corrupted state
or a timeout.

Fix this by rewriting the polling state machine:
1. Decouple polling from the global allocator by introducing a per-slot
   'completed' flag, synchronized via smp_store_release() and
   smp_load_acquire().
2. Strip acpm_get_saved_rx() out of acpm_get_rx() to make it a pure
   queue-draining function. Introduce a 'native_match' boolean argument
   which evaluates to true only if the thread natively processed its
   own sequence number during the call. This explicitly informs the
   polling loop whether it must retrieve its payload from the
   cross-thread cache.
3. Centralize the cache fallback and sequence number free (clear_bit)
   inside the polling loop. Crucially, the free operation now strictly
   targets the thread's own TX sequence number (xfer->txd[0]), rather
   than the drained RX sequence number. This enforces strict ownership:
   a thread only ever frees its own allocated sequence slot, and only
   at the exact moment it completes its poll, eliminating the UAF
   window.

Furthermore, explicitly guard the 'native_match' assignment with an
if (rx_seqnum == tx_seqnum) check, even for zero-length (no payload)
responses. While an unguarded assignment wouldn't crash (because the
cache fallback acpm_get_saved_rx() safely returns early on zero-length
transfers) doing so would "lie" to the state machine. If a thread
drained the queue and found another thread's zero-length message,
setting native_match = true would falsely convince the polling loop
that it natively handled its own response. Maintaining a rigorous state
machine requires that native_match is only set when a thread explicitly
processes its own sequence number.

Cc: stable@vger.kernel.org
Fixes: a88927b534 ("firmware: add Exynos ACPM protocol driver")
Closes: https://sashiko.dev/#/patchset/20260429-acpm-fixes-sashiko-reports-v3-0-47cf74ab09ad%40linaro.org [1]
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://patch.msgid.link/20260505-acpm-fixes-sashiko-reports-v5-5-43b5ee7f1674@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
2026-05-29 14:11:22 +02:00
Nathan Chancellor
8de061ca14 drm/msm: Restore second parameter name in purge() and evict()
After commit 3392291fc5 ("drm/msm: Fix shrinker deadlock"), all
supported versions of clang warn (or error with CONFIG_WERROR=y):

  drivers/gpu/drm/msm/msm_gem_shrinker.c:105:58: error: omitting the parameter name in a function definition is a C23 extension [-Werror,-Wc23-extensions]
    105 | purge(struct drm_gem_object *obj, struct ww_acquire_ctx *)
        |                                                          ^
  drivers/gpu/drm/msm/msm_gem_shrinker.c:117:58: error: omitting the parameter name in a function definition is a C23 extension [-Werror,-Wc23-extensions]
    117 | evict(struct drm_gem_object *obj, struct ww_acquire_ctx *)
        |                                                          ^
  2 errors generated.

With older but supported versions of GCC, this is an unconditional hard error:

  drivers/gpu/drm/msm/msm_gem_shrinker.c: In function 'purge':
  drivers/gpu/drm/msm/msm_gem_shrinker.c:105:35: error: parameter name omitted
   purge(struct drm_gem_object *obj, struct ww_acquire_ctx *)
                                     ^~~~~~~~~~~~~~~~~~~~~~~
  drivers/gpu/drm/msm/msm_gem_shrinker.c: In function 'evict':
  drivers/gpu/drm/msm/msm_gem_shrinker.c:117:35: error: parameter name omitted
   evict(struct drm_gem_object *obj, struct ww_acquire_ctx *)
                                     ^~~~~~~~~~~~~~~~~~~~~~~

Restore the parameter name to clear up the warnings, renaming it
"unused" to make it clear it is only needed to satisfy the prototype of
drm_gem_lru_scan().

Cc: stable@vger.kernel.org
Fixes: 3392291fc5 ("drm/msm: Fix shrinker deadlock")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/725924/
Link: https://lore.kernel.org/r/20260518-drm-msm-fix-c23-extensions-v1-1-0833559418c7@kernel.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
2026-05-29 15:08:00 +03:00
Dmitry Baryshkov
24acb35682 drm/msm/dp: clear EDID on display unplug
Currently the driver only updates the EDID when it detects a connected
monitor, which results in the connector still listing outdated modes
even after the display is unplugged. Set connector's EDID to NULL on
unplug to clear the list of modes.

Tested-by: Val Packett <val@packett.cool> # x1e80100-dell-latitude-7455
Tested-by: Yongxing Mou <yongxing.mou@oss.qualcomm.com> # Hamoa IOT EVK, QCS8300 Ride
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/727619/
Link: https://lore.kernel.org/r/20260524-hpd-refactor-v6-10-cf3ab488dd7b@oss.qualcomm.com
2026-05-29 14:59:26 +03:00
Dmitry Baryshkov
3ea2d1c3d1 drm/msm/dp: turn link_ready into plugged
Tracking when the DP link is ready isn't that useful from the driver
point of view. It doesn't provide a direct information if the device
should be suspended, etc. Replace it with the 'plugged' boolean, which
is set when the driver knows that there is DPRX plugged.

Tested-by: Val Packett <val@packett.cool> # x1e80100-dell-latitude-7455
Tested-by: Yongxing Mou <yongxing.mou@oss.qualcomm.com> # Hamoa IOT EVK, QCS8300 Ride
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/727614/
Link: https://lore.kernel.org/r/20260524-hpd-refactor-v6-9-cf3ab488dd7b@oss.qualcomm.com
2026-05-29 14:59:22 +03:00
Jessica Zhang
c2aed45fda drm/msm/dp: Add sink_count to debug logs
Add sink count to the debug logs for [un]plug and HPD IRQ handling.

Signed-off-by: Jessica Zhang <jessica.zhang@oss.qualcomm.com>
[DB: dropped link_ready handling]
Tested-by: Val Packett <val@packett.cool> # x1e80100-dell-latitude-7455
Tested-by: Yongxing Mou <yongxing.mou@oss.qualcomm.com> # Hamoa IOT EVK, QCS8300 Ride
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/727620/
Link: https://lore.kernel.org/r/20260524-hpd-refactor-v6-8-cf3ab488dd7b@oss.qualcomm.com
2026-05-29 14:58:52 +03:00
Jessica Zhang
5043357e75 drm/msm/dp: rework HPD handling
Handling of the HPD events in the MSM DP driver is plagued with lots of
problems. It tries to work aside of the main DRM framework, handling the
HPD signals on its own. There are two separate paths, one for the HPD
signals coming from the DP HPD pin and another path for signals coming
from outside (e.g. from the Type-C AltMode). It lies about the connected
state, returning the link established state instead. It is not easy to
understand or modify it. Having a separate event machine doesn't add
extra clarity.

Drop the whole event machine. When the DP receives a HPD event, send it
to the DRM core. Then handle the events in the hpd_notify callback,
unifying paths for HPD signals.

Signed-off-by: Jessica Zhang <jessica.zhang@oss.qualcomm.com>
Tested-by: Val Packett <val@packett.cool> # x1e80100-dell-latitude-7455
Tested-by: Yongxing Mou <yongxing.mou@oss.qualcomm.com> # Hamoa IOT EVK, QCS8300 Ride
Co-developed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/727616/
Link: https://lore.kernel.org/r/20260524-hpd-refactor-v6-7-cf3ab488dd7b@oss.qualcomm.com
2026-05-29 14:58:52 +03:00
Dmitry Baryshkov
c5d65a2b48 drm/msm/dp: drop event data
With EV_USER_NOTIFICATION gone event's data is no longer useful. Drop
it, removing also the argument from event handlers.

Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Tested-by: Val Packett <val@packett.cool> # x1e80100-dell-latitude-7455
Tested-by: Yongxing Mou <yongxing.mou@oss.qualcomm.com> # Hamoa IOT EVK, QCS8300 Ride
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/727610/
Link: https://lore.kernel.org/r/20260524-hpd-refactor-v6-6-cf3ab488dd7b@oss.qualcomm.com
2026-05-29 14:58:52 +03:00
Jessica Zhang
168dacddc3 drm/msm/dp: Drop EV_USER_NOTIFICATION
Currently, we queue an event for signalling HPD connect/disconnect. This
can mean a delay in plug/unplug handling and notifying DRM core when a
hotplug happens.

Drop EV_USER_NOTIFICATION and signal the IRQ event as part of hotplug
handling.

Signed-off-by: Jessica Zhang <jessica.zhang@oss.qualcomm.com>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Acked-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Tested-by: Val Packett <val@packett.cool> # x1e80100-dell-latitude-7455
Tested-by: Yongxing Mou <yongxing.mou@oss.qualcomm.com> # Hamoa IOT EVK, QCS8300 Ride
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/727607/
Link: https://lore.kernel.org/r/20260524-hpd-refactor-v6-5-cf3ab488dd7b@oss.qualcomm.com
2026-05-29 14:58:52 +03:00
Jessica Zhang
6fe5a253d7 drm/msm/dp: Move link training to atomic_enable()
Currently, the DP link training is being done during HPD. Move
link training to atomic_enable() in accordance with the atomic_enable()
documentation.

Link disabling is already done in atomic_post_disable() (as part of the
dp_ctrl_off_link_stream() helper).

Signed-off-by: Jessica Zhang <jessica.zhang@oss.qualcomm.com>
Tested-by: Val Packett <val@packett.cool> # x1e80100-dell-latitude-7455
Tested-by: Yongxing Mou <yongxing.mou@oss.qualcomm.com> # Hamoa IOT EVK, QCS8300 Ride
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Acked-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/727606/
Link: https://lore.kernel.org/r/20260524-hpd-refactor-v6-4-cf3ab488dd7b@oss.qualcomm.com
2026-05-29 14:58:52 +03:00
Jessica Zhang
0f2293dfb5 drm/msm/dp: Read DPCD and sink count in bridge detect()
Instead of relying on the link_ready flag to specify if DP is connected,
read the DPCD bits and get the sink count to accurately detect if DP is
connected.

Signed-off-by: Jessica Zhang <jessica.zhang@oss.qualcomm.com>
Tested-by: Val Packett <val@packett.cool> # x1e80100-dell-latitude-7455
Tested-by: Yongxing Mou <yongxing.mou@oss.qualcomm.com> # Hamoa IOT EVK, QCS8300 Ride
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/727603/
Link: https://lore.kernel.org/r/20260524-hpd-refactor-v6-3-cf3ab488dd7b@oss.qualcomm.com
2026-05-29 14:58:52 +03:00
Jessica Zhang
3fbfdc3b1d drm/msm/dp: Fix the ISR_* enum values
The ISR_HPD_* enum should represent values that can be read from the
REG_DP_DP_HPD_INT_STATUS register. Swap ISR_HPD_IO_GLITCH_COUNT and
ISR_HPD_REPLUG_COUNT to map them correctly to register values.

While we are at it, correct the spelling for ISR_HPD_REPLUG_COUNT.

Fixes: 8ede2ecc3e ("drm/msm/dp: Add DP compliance tests on Snapdragon Chipsets")
Signed-off-by: Jessica Zhang <jessica.zhang@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Tested-by: Val Packett <val@packett.cool> # x1e80100-dell-latitude-7455
Tested-by: Yongxing Mou <yongxing.mou@oss.qualcomm.com> # Hamoa IOT EVK, QCS8300 Ride
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/727602/
Link: https://lore.kernel.org/r/20260524-hpd-refactor-v6-2-cf3ab488dd7b@oss.qualcomm.com
2026-05-29 14:58:51 +03:00
Jessica Zhang
2e6c2e81d8 drm/msm/dp: fix HPD state status bit shift value
The HPD state status is the 3 most significant bits, not 4 bits of the
HPD_INT_STATUS register.

Fix the bit shift macro so that the correct bits are returned in
msm_dp_aux_is_link_connected().

Fixes: 19e52bcb27 ("drm/msm/dp: return correct connection status after suspend")
Signed-off-by: Jessica Zhang <jessica.zhang@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Tested-by: Val Packett <val@packett.cool> # x1e80100-dell-latitude-7455
Tested-by: Yongxing Mou <yongxing.mou@oss.qualcomm.com> # Hamoa IOT EVK, QCS8300 Ride
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/727611/
Link: https://lore.kernel.org/r/20260524-hpd-refactor-v6-1-cf3ab488dd7b@oss.qualcomm.com
2026-05-29 14:58:51 +03:00
Monish Chunara
4401e07263 dt-bindings: mmc: sdhci-msm: Document the Shikra compatible
Document the Shikra-specific SDHCI compatible in the sdhci-msm binding.
Use "qcom,sdhci-msm-v5" as the fallback compatible for the MSM SDHCI v5
controller used on Shikra.

Signed-off-by: Monish Chunara <monish.chunara@oss.qualcomm.com>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Ulf Hansson <ulfh@kernel.org>
2026-05-29 13:56:51 +02:00
Godswill Onwusilike
ac75f6d606 docs: gpu: todo: fix spelling of "fucntion"
Correct the spelling of "fucntion" to "function" in
Documentation/gpu/todo.rst.

v2:

Fix the actual typo instead of newline-only change

Signed-off-by: Godswill Onwusilike <onwusilikegodswill@gmail.com>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patch.msgid.link/20260528223715.26645-1-onwusilikegodswill@gmail.com
2026-05-29 13:48:10 +02:00
Godswill Onwusilike
6a391474a8 docs: gpu: drm-uapi: fix spelling of "unprivileged"
Correct the spelling of "unpriviledged" to "unprivileged" in DRM uAPI documentation.

Signed-off-by: Godswill Onwusilike <onwusilikegodswill@gmail.com>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patch.msgid.link/20260516203015.33466-1-onwusilikegodswill@gmail.com
2026-05-29 13:47:53 +02:00
Francois Dugast
25d912475e gpu/buddy: Track per-order used blocks with a scoreboard
Extend the scoreboard approach from the previous commit to used blocks,
so drm_buddy_print() can report per-order allocation pressure in O(1).

Unlike free blocks, an allocated block can leave the allocated state
through mark_free() (normal free and gpu_buddy_block_trim()) or be
consumed directly by gpu_block_free() during coalescing. Both sites are
guarded by gpu_buddy_block_is_allocated() and paired with the increment
in mark_allocated().

v3:
- Assert scoreboard is empty at fini(), as sanity check (Matthew Auld)

v2:
- Update after fix for use-after-free in split_block() call sites
- Change goto label to out_free_used_scoreboard for clarity
- Make drm_buddy_print() and gpu_buddy_print() symmetric for used and
  free

Assisted-by: GitHub Copilot:claude-sonnet-4.6
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://lore.kernel.org/r/20260522092600.32818-6-francois.dugast@intel.com
Signed-off-by: Francois Dugast <francois.dugast@intel.com>
2026-05-29 13:44:01 +02:00
Francois Dugast
a03721ee48 gpu/buddy: Track per-order free blocks with a scoreboard
Reporting per-order free block counts in drm_buddy_print() currently
requires walking all rbtrees, which is O(n) over the total number of
free blocks and holds the allocator lock for the duration. This becomes
expensive on large VRAM heaps with many small free fragments.

Maintain a free_scoreboard[] array indexed by order instead, so that
the count for any order is always available in O(1). The scoreboard is
kept accurate by hooking into the four places where a block's free state
changes: mark_free(), mark_allocated(), mark_split(), and the sites in
__gpu_buddy_free(), __force_merge(), and the four err_undo paths that
call rbtree_remove() directly on free blocks without going through
mark_*().

The print functions are simplified as a result: the rbtree traversal
is replaced by a direct array lookup.

v3: Update after introducing __gpu_buddy_undo_splits() helper

v2: Update after fix for use-after-free in split_block() call sites

Assisted-by: GitHub Copilot:claude-sonnet-4.6
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://lore.kernel.org/r/20260522092600.32818-5-francois.dugast@intel.com
Signed-off-by: Francois Dugast <francois.dugast@intel.com>
2026-05-29 13:44:00 +02:00
Francois Dugast
e16ac0132f gpu/buddy: Introduce __gpu_buddy_undo_splits() helper
The pattern of merging a block back with its buddy on error paths is
duplicated across multiple locations. Extract it into a
__gpu_buddy_undo_splits() helper to avoid repetition and prepare for
future changes.

Suggested-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://lore.kernel.org/r/20260522092600.32818-4-francois.dugast@intel.com
Signed-off-by: Francois Dugast <francois.dugast@intel.com>
2026-05-29 13:44:00 +02:00
Francois Dugast
51d28339bf gpu/buddy: Remove redundant condition in alloc_from_freetree() error path
The err_undo label in alloc_from_freetree() is only reachable via a
goto from inside the `while (tmp != order)` loop, which means tmp is
guaranteed to differ from order at that point. The surrounding
`if (tmp != order)` guard was therefore always true and can be dropped
without any behavioral change.

Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://lore.kernel.org/r/20260522092600.32818-3-francois.dugast@intel.com
Signed-off-by: Francois Dugast <francois.dugast@intel.com>
2026-05-29 13:44:00 +02:00
Francois Dugast
0251963afd gpu/buddy: Fix use-after-free in split_block() call sites
When split_block() fails it returns before calling mark_split(), leaving
the block in the FREE state and still linked in the rbtree.  The four
err_undo paths then call __gpu_buddy_free() without first removing the
block from the tree, which leads to two distinct bugs:

 - If the buddy is also free, __gpu_buddy_free() merges the two siblings
   by calling gpu_block_free(mm, block) while block->rb is still linked
   in the tree.  Any subsequent rbtree traversal will follow the now-
   dangling pointer, causing a use-after-free.

 - In alloc_from_freetree(), where there is no buddy guard,
   __gpu_buddy_free() always reaches mark_free() -> rbtree_insert() with
   block still in the tree, corrupting the rbtree.

The same pattern is already used correctly in __force_merge(): call
rbtree_remove() to unlink the block before handing it to
__gpu_buddy_free().  Apply the same fix to all four err_undo sites.

Reported-by: Sashiko <sashiko-bot@kernel.org>
Assisted-by: GitHub Copilot:claude-sonnet-4.6
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://lore.kernel.org/r/20260522092600.32818-2-francois.dugast@intel.com
Signed-off-by: Francois Dugast <francois.dugast@intel.com>
2026-05-29 13:44:00 +02:00
Michael Riesch
a34ae4f44c arm64: dts: rockchip: add radxa camera 4k on rock 5b+ cam1
Add device tree overlay for the Radxa Camera 4K (featuring the Sony IMX415
image sensor) to applied on the Radxa ROCK 5B+ CAM1 port.

Signed-off-by: Michael Riesch <michael.riesch@collabora.com>
Link: https://patch.msgid.link/20260522-rk3588-vicap-v5-7-d1d1f5265c56@collabora.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
2026-05-29 13:42:02 +02:00
Michael Riesch
bfc2779116 arm64: dts: rockchip: add radxa camera 4k on rock 5b+ cam0
Add device tree overlay for the Radxa Camera 4K (featuring the Sony IMX415
image sensor) to applied on the Radxa ROCK 5B+ CAM0 port.

Signed-off-by: Michael Riesch <michael.riesch@collabora.com>
Link: https://patch.msgid.link/20260522-rk3588-vicap-v5-6-d1d1f5265c56@collabora.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
2026-05-29 13:42:02 +02:00
Michael Riesch
c7126247fb arm64: dts: rockchip: add vicap node to rk3588
Add the device tree node for the RK3588 Video Capture (VICAP) unit.

Signed-off-by: Michael Riesch <michael.riesch@collabora.com>
[converted reg values in vicap ports to hexadecimal, to have them align
 with the port@X values, and be less confusing]
Link: https://patch.msgid.link/20260522-rk3588-vicap-v5-5-d1d1f5265c56@collabora.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
2026-05-29 13:42:02 +02:00
Matthew Wilcox (Oracle)
11ff85db51 block: Include bvec.h kernel-doc in the htmldocs
People have gone to the trouble of writing this kernel-doc; the
least we can do is publish it.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@linux.dev>
Link: https://patch.msgid.link/20260528175905.1102280-3-willy@infradead.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-29 05:34:25 -06:00
Matthew Wilcox (Oracle)
ca36c1aaee block: Add bvec_folio()
This is a simple helper which replaces page_folio(bvec->bv_page).
Minor improvement in readability, but the real motivation is to reduce
the number of references to bvec->bv_page so that it can be changed
with less work.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Leon Romanovsky <leon@kernel.org>
Reviewed-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@linux.dev>
Link: https://patch.msgid.link/20260528175905.1102280-2-willy@infradead.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-29 05:34:24 -06:00
Laurent Pinchart
f78073e84c Revert "media: renesas: vsp1: brx: Fix format propagation"
This reverts commit 937f3e6b51.

The change to format propagation in the BRx broke configuration of the
DRM pipeline. Revert it to fix the regression.

The original commit was meant to fix a v4l2-compliance failure, with no
known userspace applications being affected beside test tools. Reverting
is the simplest option, a more comprehensive fix can be developed (and
tested more thoroughly) later.

Reported-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Closes: https://lore.kernel.org/linux-media/CA+V-a8t481xuwava0nb7uY9CUPqFWZ_8EP0xrK3BgumP7HDcLg@mail.gmail.com
Fixes: 937f3e6b51 ("media: renesas: vsp1: brx: Fix format propagation")
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # On RZ/T2H
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://patch.msgid.link/20260506215650.1897177-3-laurent.pinchart+renesas@ideasonboard.com
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
2026-05-29 13:32:05 +02:00
Laurent Pinchart
a0d8f7ac03 Revert "media: renesas: vsp1: Initialize format on all pads"
This reverts commit 133ac42af0.

The change to format initialization, along with the change to format
propagation in the BRx in commit 937f3e6b51 ("media: renesas: vsp1:
brx: Fix format propagation"), broke configuration of the DRM pipeline.
Revert it to fix the regression.

The original commit was meant to fix a v4l2-compliance failure, with no
known userspace applications being affected beside test tools. Reverting
is the simplest option, a more comprehensive fix can be developed (and
tested more thoroughly) later.

Fixes: 133ac42af0 ("media: renesas: vsp1: Initialize format on all pads")
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # On RZ/T2H
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://patch.msgid.link/20260506215650.1897177-2-laurent.pinchart+renesas@ideasonboard.com
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
2026-05-29 13:32:05 +02:00
Michael Kelley
1502b42819
drm/hyperv: Use "hv_drm_" as symbol name prefix
Function and structure names in the Hyper-V DRM driver currently
use "hyperv_" as the prefix. This conflicts with usage in core Hyper-V
and VMBus code, and incorrectly implies that functions and structures
in this driver apply generically to Hyper-V. A specific conflict arises
for "hyperv_init", which is an initcall for generic Hyper-V
initialization on arm64. The conflict prevents the use of
initcall_blacklist on the kernel boot line to skip loading this driver.

Fix this by substituting "hv_drm_" as the prefix for all functions and
structures in this driver. In most places, this is replacing "hyperv_"
with "hv_drm_". In a few places, the substitution results in
"hv_drm_drm_", which has been collapsed to just "hv_drm_". In two
cases, the existing prefix is a bare "hv" (including in the to_hv()
macro), which has been replaced with "hv_drm" for consistency.

The changes are all mechanical text substitution in symbol names.
There are no other code or functional changes.

Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Hamza Mahfooz <someguy@effective-light.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20260529014826.41256-1-mhklkml@zohomail.com
2026-05-29 07:08:30 -04:00
Rik van Riel
3b7be8e7fa sched/fair: Use rq_clock() in update_tg_load_avg() rate-limit
update_tg_load_avg() is called once per leaf cfs_rq from the
__update_blocked_fair() walk that runs inside the NOHZ idle-balance
softirq, and again from update_load_avg() with UPDATE_TG.  Its first
operation after the trivial early-outs is unconditionally:

	now = sched_clock_cpu(cpu_of(rq_of(cfs_rq)));
	if (now - cfs_rq->last_update_tg_load_avg < NSEC_PER_MSEC)
		return;

Jakub ran into a system where nohz_idle_balance() was taking 75%
of a CPU (which is handling network traffic and doing many irq_exit_cpu
calls), with 35% of that CPU spent in update_load_avg, and 17% of the
CPU in sched_clock_cpu(), reading the TSC.

In a quick synthetic test, it looks like this patch reduces the
CPU use of sched_balance_update_blocked_averages by about 20%.

Switch the rate-limit to read rq_clock(rq_of(cfs_rq)) instead.
This eliminates the rdtsc, and uses a fairly fresh timestamp,
because all callers of update_tg_load_avg() and clear_tg_load_avg()
hold rq->lock and have called update_rq_clock(rq) within microseconds:

  caller                                   pre-state
  __update_blocked_fair                    encloser did update_rq_clock(rq)
  update_load_avg's three UPDATE_TG sites  under rq->lock after enqueue/dequeue/update_curr
  attach_/detach_entity_cfs_rq             preceded by update_load_avg(...)
  clear_tg_load_avg via offline path       rq_clock_start_loop_update(rq) upfront

so rq->clock is fresh at every call.  Since cfs_rqs are per-CPU
per-task_group, cfs_rq->last_update_tg_load_avg is always compared
against the same rq's clock; no cross-rq drift.

Signed-off-by: Rik van Riel <riel@surriel.com>
Assisted-by: Claude (Anthropic)
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://patch.msgid.link/20260527110250.6a91718d@fangorn
2026-05-29 12:43:16 +02:00
Andrea Righi
c6aa079968 selftests/sched_ext: Validate dl_server attach/detach in total_bw test
Extend the total_bw selftest to validate the fair/ext dl_server
auto-attach/detach operations.

After the existing consistency checks, the test now doubles the
fair_server's runtime on every CPU via debugfs and verifies that:
 1. total_bw grew after the customization (proves fair_server was
    attached and apply_params() honored the dl_bw_attached flag),
 2. with the minimal BPF scheduler loaded, total_bw drops back to the
    baseline value (proves fair_server was detached and ext_server was
    attached at its own default runtime),
 3. after unload total_bw matches the doubled value from step 1 (proves
    fair_server was re-attached with the runtime customization preserved
    across the load/unload cycle).

Signed-off-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://patch.msgid.link/20260526164420.638711-3-arighi@nvidia.com
2026-05-29 12:43:16 +02:00
Andrea Righi
e7b63427fd sched_ext: Auto-register/unregister dl_server reservations
Commit cd959a3562 ("sched_ext: Add a DL server for sched_ext tasks")
introduced an ext_server deadline server to protect sched_ext tasks from
fair/RT starvation, mirroring the existing fair_server.

Currently, both servers reserve their 50ms/1000ms bandwidth at boot,
regardless of whether a BPF scheduler is loaded. Unused bandwidth is
still reclaimed at runtime by other classes, but the static reservation
prevents the RT class from implicitly using that headroom when one of
the two classes is guaranteed to be empty.

A sysadmin can work around this by writing
/sys/kernel/debug/sched/{fair,ext}_server/cpu*/runtime, but that
requires manual action and not all systems expose debugfs.

A better approach is to make server bandwidth reservations dynamic: only
the scheduling policy that is currently active should register its
reservation, while the inactive one should not artificially hold
capacity (keeping both reservations only when the BPF scheduler is
running in partial mode):

 +---------------------------------------------+-------------+------------+
 | BPF scheduler state                         | fair server | ext server |
 +---------------------------------------------+-------------+------------+
 | not loaded (default boot)                   | reserved    | none       |
 | loaded full mode (!SCX_OPS_SWITCH_PARTIAL)  | none        | reserved   |
 | loaded partial mode (SCX_OPS_SWITCH_PARTIAL)| reserved    | reserved   |
 +---------------------------------------------+-------------+------------+

To achieve this, introduce an "attached/detached" state for each
deadline server, so the kernel can decide whether a server's bandwidth
should be accounted in global bandwidth tracking.

At boot, the system starts with only the fair server contributing to
bandwidth accounting. When a BPF scheduler is enabled, the ext server is
attached and may replace or complement the fair server depending on
whether full or partial mode is used. When sched_ext is disabled, the
system restores the previous deadline bandwidth values and behavior.

The transition logic ensures that switching between scheduling modes is
consistent and reversible, without losing runtime configuration or
requiring manual intervention.

Signed-off-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://patch.msgid.link/20260526164420.638711-2-arighi@nvidia.com
2026-05-29 12:43:15 +02:00
Andrea Righi
4043f54984 sched/deadline: Reject debugfs dl_server writes for offline CPUs
Writing runtime or period via the per-CPU dl_server debugfs files
(/sys/kernel/debug/sched/{fair,ext}_server/cpu*/{runtime,period}) on an
offline CPU can trigger two distinct kernel issues:

1) Divide-by-zero in dl_server_apply_params():

  Oops: divide error: 0000 [#1] SMP NOPTI
  RIP: 0010:dl_server_apply_params+0x239/0x3a0
  Call Trace:
   sched_server_write_common.isra.0+0x21a/0x3c0
   full_proxy_write+0x78/0xd0
   vfs_write+0xe7/0x6e0

  Both __dl_sub() and __dl_add() divide by cpus internally, which can be
  0 once the CPU has been removed from any active root-domain span (this
  has been latent since the debugfs interface was introduced).

2) WARN_ON_ONCE in dl_server_start():

  WARNING: kernel/sched/deadline.c:1805 at dl_server_start+0x232/0x270

  Commit ee6e44dfe6 ("sched/deadline: Stop dl_server before CPU goes
  offline") added this check to catch enqueueing the server on an
  offline rq.

There's no meaningful semantics for re-configuring the per-CPU dl_server
bandwidth while the CPU is offline, so simply reject the write with
-EBUSY so userspace gets a clear error.

Closes: https://lore.kernel.org/all/20260526092228.3B6891F00A3A@smtp.kernel.org/
Fixes: d741f297bc ("sched/fair: Fair server interface")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Juri Lelli <juri.lelli@redhat.com>
Tested-by: abaci-kreproducer <abaci@linux.alibaba.com>
Link: https://patch.msgid.link/20260526100502.575774-1-arighi@nvidia.com
2026-05-29 12:43:15 +02:00