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1,412,329 commits

Author SHA1 Message Date
Jouni Högander
3a49c54eef drm/i915/psr: Do PSR exit on frontbuffer flush on LunarLake and onwards
We need to use intel_psr_exit in frontbuffer flush on LunarLake and
onwards if we want to move using trans push mechanism to trigger Frame
Change event.

Keep PSR1 and PSR2 HW tracking as it is for older platforms as this was
seen causing problems there.

v2: typo fixed

Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patch.msgid.link/20260127124120.1069026-10-jouni.hogander@intel.com
2026-02-02 08:13:39 +02:00
Jouni Högander
74222f79bc drm/i915/psr: Wait for idle only after possible send push
We are planning to move using trans push mechanism to trigger the Frame
Change event. In that case we can't wait PSR to idle before send push
happens. Due to this move wait for idle to be done after possible send push
is done.

This should be ok for Frame Change event triggered by register write as
well. Wait for idle is needed only for corner case where PSR is
transitioning into DEEP_SLEEP when Frame Change event is triggered. It just
has to be before wait for vblank. Otherwise we may have vblank before PSR
enters DEEP_SLEEP and still using old frame buffers for first frame after
wake up.

v2: some typos fixed

Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patch.msgid.link/20260127124120.1069026-9-jouni.hogander@intel.com
2026-02-02 08:13:39 +02:00
Jouni Högander
7bb01e3265 drm/i915/display: Wait for vblank in case of PSR is using trans push
In case PSR uses trans push as a "frame change" event and we need to wait
vblank after triggering PSR "frame change" event. Otherwise we may miss
selective updates.

DSB skips all waits while PSR is active. Check push send is skipped as well
because trans push send bit is not reset by the HW if VRR is not enabled ->
we may start configuring new selective update while previous is not
complete. Avoid this by waiting for vblank after sending trans push.

v2: some typos fixed

Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patch.msgid.link/20260127124120.1069026-8-jouni.hogander@intel.com
2026-02-02 08:13:39 +02:00
Jouni Högander
f8c7baf813 drm/i915/dsb: Set DSB_SKIP_WAITS_EN chicken bit for LunarLake and onwards
On LunarLake we are using TRANS_PUSH mechanism to trigger "Frame Change"
event. This way we have more control on when PSR HW is woken up. I.e. not
every display register write is triggering sending update. This allows us
setting DSB_SKIP_WAITS_EN chicken bit as well.

Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patch.msgid.link/20260127124120.1069026-7-jouni.hogander@intel.com
2026-02-02 08:13:39 +02:00
Jouni Högander
0dcead77c1 drm/i915/vrr: Prepare to Use TRANS_PUSH mechanism for PSR frame change
On Lunarlake and onward it is possible to generate PSR Frame Change
event using TRANS_PUSH mechanism:

Ensure push is performed on flip if needed by PSR.

Don't use intel_psr_trigger_frame_change_event if PSR uses trans push as
Frame Change event: When not using trans push to generate Frame Change
event plane/pipe register writes are triggering the event. This is causing
problems when transiting to PSR active/idle and the event is coming in. To
tackle this we are waiting PSR to idle and using
intel_psr_trigger_frame_change_event to ensure PSR exit. If the Frame
change event is triggered after everything is configured (on trans push) we
don't need to worry about all this.

Ensure possible intel_vrr_tg_disable call is not overwriting
LNL_TRANS_PUSH_PSR_PR_EN.

v8:
  - split adding intel_vrr_psr_frame_change_enable as a separate change
  - update commit message
v7:
  - HAS_PSR_FRAME_CHANGE macro moved to separate patch and renamed as
    HAS_PSR_TRANS_PUSH_FRAME_CHANGE
  - use intel_psr_use_trans_push instead of HAS_PSR_FRAME_CHANGE in
    intel_psr_trigger_frame_change
  - moved calling intel_vrr_psr_frame_change_enable away from this patch
v6:
  - add HAS_PSR_FRAME_CHANGE macro
  - use TRANS_PUSH in instead of TRAN_VRR_CTL
v5: use intel_psr_use_trans_push for intel_vrr_psr_frame_change_enable
v4:
  - use rmw when enabling/disabling transcoder
  - set TRANS_PUSH_EN conditionally in intel_vrr_send_push
  - do not call intel_vrr_send_push from intel_psr_trigger_frame_change
  - do not enable using TRANS_PUSH mechanism for PSR "Frame Change"
v3:
  - use rmw when enabling/disabling
  - keep LNL_TRANS_PUSH_PSR_PR_EN set always on LunarLake and onwards
v2: use intel_vrr_trans_push_enabled_set_clear instead of rmw

Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patch.msgid.link/20260127124120.1069026-6-jouni.hogander@intel.com
2026-02-02 08:13:39 +02:00
Jouni Högander
ef7ae0e3f6 drm/i915/vrr: Add helper for PSR to enable Frame Change event on trans push
Add new helper to enable PSR Frame Change event generation using trans push
mechanism. This helper is to be used by PSR code on PSR enable.

Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patch.msgid.link/20260127124120.1069026-5-jouni.hogander@intel.com
2026-02-02 08:13:39 +02:00
Jouni Högander
37d4001a72 drm/i915/vrr: Add helper for parsing value to be written into TRANS_PUSH
On Lunarlake and onwards it is possible to generate PSR "frame change"
event using TRANS_PUSH mechanism. As a preparation add new helper to parse
value to be written into TRANS_PUSH register. Setting
LNL_TRANS_PUSH_PSR_PR_EN is done in upcoming change.

Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patch.msgid.link/20260127124120.1069026-4-jouni.hogander@intel.com
2026-02-02 08:13:39 +02:00
Jouni Högander
28b086fd19 drm/i915/psr: Add intel_psr_use_trans_push to query if TRANS_PUSH is used
This is a preparation to start using trans push as a PSR "Frame Change"
event. It adds intel_psr_use_trans_push placeholder which return false for
now until we have everything in place.

v2:
  - modify commit message
  - add TODO

Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patch.msgid.link/20260127124120.1069026-3-jouni.hogander@intel.com
2026-02-02 08:13:39 +02:00
Jouni Högander
134f3c7022 drm/i915/psr: Add TRANS_PUSH register bit definition for PSR
Add TRANS_PUSH register bit LNL_TRANS_PUSH_PSR_PR_EN definition for PSR
usage.

v2: add bspec reference

Bspec: 69984
Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patch.msgid.link/20260127124120.1069026-2-jouni.hogander@intel.com
2026-02-02 08:13:39 +02:00
Michał Grzelak
ecb21d6156 drm/i915: move intel_gvt_init() level higher
Both initialisation and removal of GVT happen at different abstraction
levels. Hence caller of i915_driver_hw_probe() has no way of knowing
status of intel_gvt_init(). This can lead to an unbalanced number of
calls of intel_gvt_init() and intel_gvt_driver_remove() since GVT error
path is currently handled in i915_driver_probe(). One such scenario has
been seen with i915_driver_hw_probe() fault injection, which caused
double entry deletion and list corruption.

Move intel_gvt_init() up to i915_driver_probe(). Add out_cleanup_gvt
error path for removing gvt. Trigger it only after intel_gvt_init()
succeeded.

In case intel_gvt_init() failed, theoretically we should follow err_msi
error path. That is actually impossible since call to intel_gvt_init()
unconditionally returns 0, although it claims to return negative error
code on failure. Thus follow standard out_cleanup_hw error path on a
hypothetical future intel_gvt_init() failure. Remove err_msi label from
i915_driver_hw_probe() since intel_gvt_init() was the only user of it.

Changelog:
v1->v2
- don't move err_msi error path from i915_driver_hw_probe (Jani)
- rewrite commit message

Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/15481
Signed-off-by: Michał Grzelak <michal.grzelak@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patch.msgid.link/20260129090129.2601661-2-michal.grzelak@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2026-01-30 11:30:26 +02:00
Jani Nikula
c0f211b249 drm/i915/gvt: drop unnecessary include of intel_display.h
This does not appear to be needed at all.

Cc: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patch.msgid.link/32359d5d5feb777ecc7c983d970823218851035f.1769612208.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2026-01-29 10:19:20 +02:00
Jani Nikula
581e9a471a drm/i915/gvt: drop dependency on intel_display_types.h
Avoid even accidental use of display details by dropping the include of
intel_display_types.h. We'll still have to include intel_dpll_mgr.h for
the DPLL IDs, but at least the surface is smaller.

Add duplicate defines of pipe_name() and port_name() to avoid depending
on display. They're trivial enough to be acceptable.

Cc: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patch.msgid.link/2fa5677f5ff3dbeaa75a7984d74fb9855a4ba3d2.1769612208.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2026-01-29 10:19:13 +02:00
Jani Nikula
a9ec4e6e7b drm/i915/gvt: drop dependency on display struct dpll
The gvt code has no real need for struct dpll, it's just a collection of
variables. So use a bunch of variables instead.

Cc: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patch.msgid.link/ff7478efa80323c638a31c578cb1d707692ef51d.1769612208.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2026-01-29 10:19:11 +02:00
Jani Nikula
dccc15e55a drm/i915/display: move enum aux_ch to intel_display_limits.h
Move enum aux_ch from intel_display.h to intel_display_limits.h to avoid
having to include the former from gvt. This currently happens via
intel_display_types.h, which we can also drop in favour of
intel_display_limits.h in intel_gvt_mmio_table.c.

Cc: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Link: https://patch.msgid.link/86ccc91ee1ca96fa145b750e2f1935918ec288d0.1769612208.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2026-01-29 10:18:53 +02:00
Gustavo Sousa
34c52c7927 drm/i915/cdclk: Extend Wa_13012396614 to Xe3p_LPD
Xe3p_LPD also needs Wa_13012396614.  Update the conditions for that
workaround accordingly.

Signed-off-by: Gustavo Sousa <gustavo.sousa@intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
Link: https://patch.msgid.link/20260122-wa_13012396614-xe3p_lpd-v1-1-39d34a3a5b77@intel.com
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
2026-01-28 16:09:25 -08:00
Jonathan Cavitt
671e1cfe5b drm/i915/display: vcpi is always greater than zero
Static analysis issue:

intel_conn_to_vcpi currently checks and asserts vcpi >= 0, as grabbed
from payload->vcpi.  But payload->vcpi is a u8, so this is always true.
Remove this unnecessary check.

While we're here, the jump statements in this function are largely
defunct now, so remove those as well.

Signed-off-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patch.msgid.link/20260123170914.64548-2-jonathan.cavitt@intel.com
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
2026-01-28 16:01:08 -08:00
Jani Nikula
b3a2a91ae9 drm/{i915, xe}/pcode: move display pcode calls to parent interface
Call the parent driver pcode functions through the parent interface
function pointers instead of expecting both to have functions of the
same name.

In i915, add the interface to existing intel_pcode.[ch], while in xe
move them to new display/xe_display_pcode.[ch] and build it only for
CONFIG_DRM_XE_DISPLAY=y.

Do not add separate write and write_timeout calls in the
interface. Instead, handle the default 1 ms timeout in the
intel_parent.c glue layer.

This drops the last intel_pcode.h includes from display, and allows us
to remove the corresponding xe compat header.

v2: initialize .pcode in i915

Reviewed-by: Michał Grzelak <michal.grzelak@intel.com>
Link: https://patch.msgid.link/20260126112925.2452171-1-jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2026-01-27 16:45:53 +02:00
Suraj Kandpal
ad381460c9 drm/i915/display: Disable DMG Clock Gating
Incorrect clock is connected to DMG registers.
Disable DMG Clock gating during display initialization.

WA: 22021451799
Bspec: 69095
Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
Reviewed-by: Nemesa Garg <nemesa.garg@intel.com>
Link: https://patch.msgid.link/20260122031818.703590-1-suraj.kandpal@intel.com
2026-01-27 09:26:35 +05:30
Suraj Kandpal
bbde2759de drm/i915/cx0: Rename intel_clear_response_ready flag
Rename the non static intel_clear_response_ready_flag to
intel_cx0_clear_response_ready_flag so that we follow the
naming standards of non static function.

Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
Reviewed-by: Nemesa Garg <nemesa.garg@intel.com>
Link: https://patch.msgid.link/20260122044859.753682-2-suraj.kandpal@intel.com
2026-01-27 08:33:35 +05:30
Suraj Kandpal
f86bed1bc9 drm/i915/cx0: Clear response ready & error bit
Clear the response ready and error bit of PORT_P2M_MESSAGE_BUS_STATUS
before writing the transaction pending bit of
PORT_M2P_MSGBUS_CTL as that is a hard requirement. If not done
we find that the PHY hangs since it ends up in a weird state if left
idle for more than 1 hour.

Bspec: 65101
Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
Reviewed-by: Gustavo Sousa <gustavo.sousa@intel.com>
Reviewed-by: Michał Grzelak <michal.grzelak@intel.com>
Link: https://patch.msgid.link/20260122044859.753682-1-suraj.kandpal@intel.com
2026-01-27 08:33:33 +05:30
Jani Nikula
cca7eda1c7 drm/{i915, xe}/dsb: move DSB buffer to parent interface
Move the DSB buffer handling to the display parent interface, making
display more independent of i915 and xe driver implementations.

Since the DSB parent interface is only called from intel_dsb.c, add the
wrappers there with smaller visibility instead of the usual
intel_parent.[ch], and using struct intel_dsb as the context parameter
for convenience.

Unfortunately, memset() being a macro in linux/fortify-string.h, we
can't use that as the function pointer name. dsb->memset() would be
using the macro and leading to build failures. Therefore, use .fill()
for the memset() functionality.

v2: s/memset/fill/

Reviewed-by: Michał Grzelak <michal.grzelak@intel.com>
Link: https://patch.msgid.link/df117c862a6d34dae340e4a85c2482b4e29c8884.1768923917.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2026-01-26 11:56:41 +02:00
Jani Nikula
1617f5955c drm/i915/dsb: move i915 specific DSB buffer implementation to i915
The DSB buffer implementation is different for both i915 and xe. Move
the i915 specific implementation from display to i915 core.

Reviewed-by: Michał Grzelak <michal.grzelak@intel.com>
Link: https://patch.msgid.link/a01b3e69a3f79713eacf437af00dbe23d2f9c8dd.1768923917.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2026-01-26 11:56:41 +02:00
Jani Nikula
ced8299146 drm/i915: move GEN7_ERR_INT snapshot to display irq code
The error interrupt register GEN7_ERR_INT is a display irq
register. Move its GPU error capture to display irq snapshot.

Cc: Uma Shankar <uma.shankar@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Link: https://patch.msgid.link/20260122123759.1701492-1-jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2026-01-23 11:14:11 +02:00
Ville Syrjälä
42bb7bdae9 drm/i915: Document the GMCH_CTRL register a bit
The actual GMCH_CRTL lives in the host bridge aka. device 0,
but device 2 has a read-only mirror on i85x/i865+. Document
that fact.

Also remove the ancient tales about where the defines are used.
Those haven't been true in a long time.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20251208182637.334-20-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
2026-01-23 05:20:58 +02:00
Ville Syrjälä
29ed5593ca drm/i915: Clean up PCI config space reg defines
The PCI config space register defines in i915_drm.h are
a bit of a mess; Whitespace is all over the place, register
masks and values are defined in inconsistent ways.

Clean it up a bit.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20251208182637.334-19-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
2026-01-23 05:20:28 +02:00
Ville Syrjälä
20382658ff drm/i915: Get rid of the INTEL_GMCH_CTRL alias
INTEL_GMCH_CTRL and I830_GMCH_CTRL are the same register.
Get rid of the INTEL_GMCH_CTRL name.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20251208182637.334-18-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
2026-01-23 05:20:28 +02:00
Ville Syrjälä
5f61ebd578 drm/i915/crt: Extract intel_crt_sense_above_threshold()
Extract the CRT sense check into a helper instead of repeating
the same thing twice.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20251208182637.334-17-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
2026-01-23 05:20:28 +02:00
Ville Syrjälä
5dc670f24b drm/i915/crt: Use IS0_R instead of VGA_MIS_W
Use the proper IS0_R name for the VGA input status register 0, instead
of using the VGA_MIS_W alias which is meant for write accesses to the
same address. Yes, VGA registers are weird.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20251208182637.334-16-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
2026-01-23 05:20:28 +02:00
Ville Syrjälä
46e51fd014 video/vga: Add VGA_IS0_R
Add a proper name for the "Input status register 0" IO address.
Currently we have some code that does reads using the aliasing
VGA_MSR_W define, making it unclear what register we're
actually reading.

v2: Remove stray '?'

Cc: Helge Deller <deller@gmx.de>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20251209075549.14051-1-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Helge Deller <deller@gmx.de>
2026-01-23 05:20:28 +02:00
Ville Syrjälä
359dd735ef drm/i915/vga: Use MMIO for VGA registers on pre-g4x
On pre-g4x VGA registers are accessible via MMIO. Make use of
it so that we can avoid dealing with the VGA arbiter.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20251208182637.334-14-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
2026-01-23 05:20:28 +02:00
Ville Syrjälä
3acd8cbbd7 drm/i915/vga: Introduce intel_vga_{read,write}()
VGA register are rather special since they either get accessed
via the global IO addresses, or possibly through MMIO on
pre-g4x platforms. Wrap all VGA register accesses in
intel_vga_{read,write}() to make it obvious where they get
accessed.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20251208182637.334-13-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
2026-01-23 05:20:27 +02:00
Ville Syrjälä
005a496d0f drm/i915/de: Add intel_de_write8()
Add a write counterpart to intel_de_read8(). Will be used for
MMIO access to VGA registers on pre-g4x.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20251208182637.334-12-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
2026-01-23 05:20:27 +02:00
Ville Syrjälä
d2bfe35f84 drm/i915/de: Simplify intel_de_read8()
intel_de_read8() is only needed for VGA register MMIO access
by the CRT code on gen2/3. Remove the redundant wakelock stuff,
and add a platform check to make sure this won't get used on
any platform where MMIO VGA register accesses don't work.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20251208182637.334-11-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
2026-01-23 05:20:27 +02:00
Ville Syrjälä
7e47a14b02 drm/i915/vga: Assert that VGA register accesses are going to the right GPU
We want our VGA register accesses to land on the correct GPU.
Check that the VGA routing is appropriately configured.

For the iGPU this just means the IO decode enable on the GPU, but
for dGPUs we also need the entire chain of bridges to forward the
VGA accesses.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20251208182637.334-10-ville.syrjala@linux.intel.com
Acked-by: Jani Nikula <jani.nikula@intel.com>
2026-01-23 05:20:27 +02:00
Ville Syrjälä
01f827140b drm/i915/vga: Stop trying to use GMCH_CTRL for VGA decode control
intel_gmch_vga_set_state() is a complete lie on ILK+ because
the GMCH_CTRL register is locked and can't actually be written.
But we still need to remove the iGPU from the VGA arbitration
on iGPU+dGPU systems, or else Xorg performance will tank due
to the constant VGA arbiter accesses.

For VGA memory decode we can't turn off the PCI_COMMAND
memory deocde as that would disable even normal MMIO.
Instead we can disable just the VGA memory decode via
the VGA MSR register. And we can do that just once
when disabling the VGA plane. That way we don't have
to touch VGA registers anywhere else.

We can also inform the arbiter that we're no longer decoding
VGA memory. This will stop the arbiter from disabling all
memory decode for the iGPU via PCI_COMMAND (and thus breaking
everything) whenever some other GPU wants to own the VGA memory
accesses.

For IO we can disable all IO decode via the PCI_COMMAND
register, except around the few VGA register accesses that
we need to do in intel_vga_disable(). Unfortunately we can't
disable IO decode permanently as it makes some laptops (eg.
Dell Latitude E5400) hang during reboot/shutdown. One option
would be to re-enable IO decode from the poweroff hooks, but
that won't help the sysrq emergency reboot/shutdown since it
won't call said hooks. So let's try to keep IO decode in its
original setting unless we really need to disable it to
exclude the GPU from VGA arbitration.

I suppose we could keep frobbing GMCH_CTRL on pre-ILK, but
it seems better to not do it since it has other side effects
such as changing the class code of the PCI device.

For discrete GPUs we'll rely on the bridge control instead.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20251208182637.334-9-ville.syrjala@linux.intel.com
Acked-by: Jani Nikula <jani.nikula@intel.com>
2026-01-23 05:20:27 +02:00
Ville Syrjälä
cc6ed470ca drm/i915/vga: Avoid VGA arbiter during intel_vga_disable() for iGPUs
Avoid using the VGA arbiter during intel_vga_get() for iGPUs because
that will clobber the VGA routing for whatever external GPU is the
current VGA device. That will cause all reads from VGA memory to
come back as 0xff/white, and thus we get a white rectangle on screen
when the external GPU switches from vgacon to fbcon.

The iGPU has the highest VGA decode priority so it will steal all
VGA register accesses whenever its IO decoding is enabled. We'll only
keep the IO decode enabled for a short time so hopefully we don't
end up eating too many unrelated VGA register accesses.

For discrete GPUs we need all the bridges to have their VGA forwarding
bits correctly configured so we can't really avoid the VGA arbiter
there. Although we only do this stuff on dGPUs when the VGA plane was
actaully enabled, so the dGPU should be the current VGA device
and thus have VGA routed to it already anyway.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20251208182637.334-8-ville.syrjala@linux.intel.com
Acked-by: Jani Nikula <jani.nikula@intel.com>
2026-01-23 05:20:27 +02:00
Ville Syrjälä
f1640f9d7f drm/i915/vga: Clean up VGA registers even if VGA plane is disabled
Turns out at least some systems (eg. HSW Lenovo ThinkCentre E73)
configure the VGA registers even when booting in UEFI mode. So
in order to avoid any issues with the MSR register we should
clean up the VGA registers anyway.

For now this mostly avoids the potential for unclaimed register
accesses due to the power well vs. MDA/CGA selection. But this
will become more important soon as we'll start to rely on the
MSR register to control VGA memory decode as well.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20251208182637.334-7-ville.syrjala@linux.intel.com
Acked-by: Jani Nikula <jani.nikula@intel.com>
2026-01-23 05:20:27 +02:00
Ville Syrjälä
46ccf3fb55 drm/i915/vga: Don't touch VGA registers if VGA decode is fully disabled
On some systems the BIOS will disable the VGA decode logic in the
iGPU (via GMCH_CTRL) when an external GPU is used as the primary
VGA device. In that case the iGPU will never claim any VGA register
accesses, and any access we do will in fact end up on the external
GPU. Don't go poking around in the other GPUs' registers.

Note that (at least on the g4x board where I tested this) the BIOS
forgets to set the VGACNTR VGA_DISP_DISABLE bit, and the reset
value for said bit is 0. That apparently prevents the pipes from
running, so we must still remember to set the bit, despite the VGA
plane was never actually enabled. On more modern platforms (hsw+
maybe?) the reset value for VGACNTR was changed to have
VGA_DISP_DISABLE already set.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20251208182637.334-6-ville.syrjala@linux.intel.com
Acked-by: Jani Nikula <jani.nikula@intel.com>
2026-01-23 05:19:33 +02:00
Ville Syrjälä
d4470842e4 drm/i915/vga: Extract intel_gmch_ctrl_reg()
Extract the GMCH_CTLR register offset determination into a helper
rather than using a local varaible. I'll be needing this in another
function soon.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20251208182637.334-5-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
2026-01-23 04:36:54 +02:00
Ville Syrjälä
284c6d8043 drm/i915/power: Remove i915_power_well_desc::has_vga
We no longer have any need for the has_vga flag in the
display power well descriptor. Get rid of it.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20251208182637.334-4-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
2026-01-23 04:36:41 +02:00
Ville Syrjälä
4d71ff25f3 drm/i915/vga: Get rid of intel_vga_reset_io_mem()
Remove the MSR VGA register access from the power well hook, and
just do it once in intel_vga_disable().

Turns out that the hardware has two levels of MDA vs. CGA decode
logic: GPU level and display engine level. When we write the MSR
register MDA/CGA mode selection bit both decode logics are updated
accordingly, so that whichever register accessed the GPU claims
will also be claimed by the display engine on the RMbus. If the
two get out of sync the GPU will claim the register accesses but
the display engine will not, leading to RMbus NoClaim errors.

The way to get the two decode logics out of sync is by resetting
the power well housing the VGA stuff, while we are in CGA mode.
At that point only the display engine level decode logic will be
updated with the new MSR register reset value (which selects MDA
mode), and the GPU level decode logic will retain its previous
state (GGA mode). To avoid the mismatch we just have to switch
to MDA mode with an explicit MSR register write.

Currently this is being done in a somewhat dodgy manner whenever
the power well gets enabled. But doing if from the power well
hook is not actually necessary since the GPU level decode logic
will retain its state even when the power well is disabled. Ie.
doing it just the one time is sufficient, and that can be done
when we're anyway writing other VGA registers while disabling
the VGA plane.

See commit f9dcb0dfee ("drm/i915: touch VGA MSR after we
enable the power well") for the original details.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20251208182637.334-3-ville.syrjala@linux.intel.com
Acked-by: Jani Nikula <jani.nikula@intel.com>
2026-01-23 04:36:31 +02:00
Ville Syrjälä
70ea362b84 drm/i915/vga: Register vgaarb client later
Currently we register to vgaarb way too early. Thus it is
possible that the entire VGA decode logic gets nuked via
GMCH_CTRL before intel_vga_disable() has even disabled the
VGA plane. This could even cause a system hang because
we'll be unable to turn off the VGA plane gracefully.

Move the vgaarb registration into intel_display_driver_register().
I suppose we could do it a bit earlier (after intel_vga_disable()),
but not convinced there's any point.

Also the error handling here is pointless since the
registration can't fail (unless the device isn't a VGA class
in which case all VGA decode logic should aleady be disabled
by the BIOS via GMCH_CTRL). But let's toss in a WARN to catch
any future breakage of vga_client_register().

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20251208182637.334-2-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
2026-01-23 04:34:09 +02:00
Ankit Nautiyal
37d5f4da49 drm/i915/gvt_mmio_table: Use the gvt versions of the display macros
Include gvt/display_helpers.h so that the display register macros in
intel_gvt_mmio_table.c expand through the exported display functions.
This lets us keep the existing macro calls while avoiding direct
access to display internals, helping the display modularization work.

Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patch.msgid.link/20260114025456.1639171-1-ankit.k.nautiyal@intel.com
2026-01-22 08:47:09 +05:30
Jonathan Cavitt
6695dc2798 drm/i915/display: Prevent u64 underflow in intel_fbc_stolen_end
Static analysis reveals a potential integer underflow in
intel_fbc_stolen_end.  This can apparently occur if
intel_parent_stolen_area_size returns zero (or, theoretically, any value
less than 2^23), as 2^23 is subtracted from the return value and stored
in a u64.  While this doesn't appear to cause any issues due to the use
of the min() function to clamp the return values from the
intel_fbc_stolen_end function, it would be best practice to avoid
undeflowing values like this on principle.  So, rework the function to
prevent the underflow from occurring.  Note that the underflow at
present would result in the value of intel_fbc_cfb_base_max being
returned at the end of intel_fbc_stolen_end, so just return that if the
value of intel_parent_stolen_area_size is too small.

While we're here, fix the other comments here and modify the execution
path for readability.

v2: (Jani)
- Fix the comments in intel_fbc_stolen_end
- Use check_sub_overflow
- Remove macro that mirrors SZ_8M, as it is now only referenced once
- Misc. formatting fixes

Fixes: a9da512b3e ("drm/i915: avoid the last 8mb of stolen on BDW/SKL")
Signed-off-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patch.msgid.link/20260107162935.8123-2-jonathan.cavitt@intel.com
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
2026-01-21 10:06:29 -08:00
Mika Kahola
301929e362 drm/i915/display: Remove .clock member from eDP/DP/HDMI pll tables
PLL state structure has a member .clock. This is not needed as
the port clock is possible to calculate from the pll dividers.
Remove the encoder from being passed to the port clock calculation
function.

v2: Keep the pll_state->clock assignment in
    intel_snps_hdmi_pll_compute_mpllb().

Signed-off-by: Mika Kahola <mika.kahola@intel.com>
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Link: https://patch.msgid.link/20260119093757.2850233-16-mika.kahola@intel.com
2026-01-20 10:53:03 +02:00
Mika Kahola
1b85f96de2 drm/i915/lt_phy: Drop 27.2 MHz rate
Drop 27.2 MHz PLL table as with these PLL dividers
the port clock will be incorrectly calculated to 27.0 MHz.
For 27.2 MHz rate the PLl dividers are calculated
algorithmically making PLL table for this rate redundant.

Signed-off-by: Mika Kahola <mika.kahola@intel.com>
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Link: https://patch.msgid.link/20260119093757.2850233-15-mika.kahola@intel.com
2026-01-20 10:53:02 +02:00
Mika Kahola
4fa244583e drm/i915/cx0: Drop C20 25.175 MHz rate
Drop C20 25.175 MHz PLL table as with these
PLL dividers the port clock will be incorrectly
calculated to 25.2 MHz. For 25.175 MHz rate the
PLl dividers are calculated algorithmically making
PLL table for this rate redundant.

Signed-off-by: Mika Kahola <mika.kahola@intel.com>
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Link: https://patch.msgid.link/20260119093757.2850233-14-mika.kahola@intel.com
2026-01-20 10:53:01 +02:00
Mika Kahola
10d187b356 drm/i915/lt_phy: Add verification for lt phy pll dividers
Add verification for lt phy pll dividers during boot. The port clock
is calculated from pll dividers and compared against the requested
port clock value. If there are a difference exceeding +-1 kHz an
drm_warn() is thrown out to indicate possible pll divider mismatch.

v2:
- Move the LT_PHY_PLL_PARAMS -> LT_PHY_PLL_DP/HDMI_PARAMS change
  earlier.
- Use tables[i].name != NULL as a terminating condition.
- Use state vs. params term consistently in intel_c10pll_verify_clock()
  and intel_c20pll_verify_clock().

Signed-off-by: Mika Kahola <mika.kahola@intel.com>
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Link: https://patch.msgid.link/20260119093757.2850233-13-mika.kahola@intel.com
2026-01-20 10:52:59 +02:00
Mika Kahola
58213c1d78 drm/i915/cx0: Verify C10/C20 pll dividers
Add verification for pll table dividers. The port clock
is computed based on pll tables and, for hdmi case, the
algorithmic model is applied to calculate pll dividers.
If port clock differs more than +-1 kHz from expected value
an drm_warn() is thrown and pll divider differences are
printed out for debugging purposes.

v2:
- Move clock derivation from dividers in intel_cx0pll_enable()
  earlier in the patchset.
- Keep intel_cx0_pll_power_save_wa() in intel_dpll_sanitize_state()
- Use tables[i].name != NULL as a terminating condition.
- Drop duplicate intel_cx0pll_clock_matches() declaration in header.
- Use state vs. params term consistently in intel_c10pll_verify_clock()
  and intel_c20pll_verify_clock().

Signed-off-by: Mika Kahola <mika.kahola@intel.com>
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Link: https://patch.msgid.link/20260119093757.2850233-12-mika.kahola@intel.com
2026-01-20 10:52:58 +02:00
Mika Kahola
50ad932880 drm/i915/cx0: Add a fuzzy check for DP/HDMI clock rates during programming
Since the clock rate is derived from the PLL divider values it can have
a +-1kHz difference wrt. the reference rates in the comparison

Signed-off-by: Mika Kahola <mika.kahola@intel.com>
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Link: https://patch.msgid.link/20260119093757.2850233-11-mika.kahola@intel.com
2026-01-20 10:52:57 +02:00