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Ahmad Fatoum 72d00e560d clk: imx: pll14xx: dynamically configure PLL for 393216000/361267200Hz
Since commit b09c68dc57 ("clk: imx: pll14xx: Support dynamic rates"),
the driver has the ability to dynamically compute PLL parameters to
approximate the requested rates. This is not always used, because the
logic is as follows:

  - Check if the target rate is hardcoded in the frequency table
  - Check if varying only kdiv is possible, so switch over is glitch free
  - Compute rate dynamically by iterating over pdiv range

If we skip the frequency table for the 1443x PLL, we find that the
computed values differ to the hardcoded ones. This can be valid if the
hardcoded values guarantee for example an earlier lock-in or if the
divisors are chosen, so that other important rates are more likely to
be reached glitch-free.

For rates (393216000 and 361267200, this doesn't seem to be the case:
They are only approximated by existing parameters (393215995 and
361267196 Hz, respectively) and they aren't reachable glitch-free from
other hardcoded frequencies. Dropping them from the table allows us
to lock-in to these frequencies exactly.

This is immediately noticeable because they are the assigned-clock-rates
for IMX8MN_AUDIO_PLL1 and IMX8MN_AUDIO_PLL2, respectively and a look
into clk_summary so far showed that they were a few Hz short of the target:

imx8mn-board:~# grep audio_pll[12]_out /sys/kernel/debug/clk/clk_summary
audio_pll2_out           0        0        0   361267196 0     0  50000   N
audio_pll1_out           1        1        0   393215995 0     0  50000   Y

and afterwards:

imx8mn-board:~# grep audio_pll[12]_out /sys/kernel/debug/clk/clk_summary
audio_pll2_out           0        0        0   361267200 0     0  50000   N
audio_pll1_out           1        1        0   393216000 0     0  50000   Y

This change is equivalent to adding following hardcoded values:

  /*               rate     mdiv  pdiv  sdiv   kdiv */
  PLL_1443X_RATE(393216000, 655,    5,    3,  23593),
  PLL_1443X_RATE(361267200, 497,   33,    0, -16882),

Fixes: 053a4ffe29 ("clk: imx: imx8mm: fix audio pll setting")
Cc: stable@vger.kernel.org # v5.18+
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Link: https://lore.kernel.org/r/20230807084744.1184791-2-m.felsch@pengutronix.de
Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
History 2023-08-14 12:52:32 +03:00
arch - Do FPU AP initialization on Xen PV too which got missed by the recent 2023-07-09 10:13:32 -07:00
block block-6.5-2023-07-03 2023-07-03 18:48:38 -07:00
certs KEYS: Add missing function documentation 2023-04-24 16:15:52 +03:00
crypto This update includes the following changes: 2023-06-30 21:27:13 -07:00
Documentation dt-bindings: clock: fsl,imx8-acm: Add audio clock mux support 2023-08-14 12:27:52 +03:00
drivers clk: imx: pll14xx: dynamically configure PLL for 393216000/361267200Hz 2023-08-14 12:52:32 +03:00
fs Minor cleanups for 6.5: 2023-07-09 09:50:42 -07:00
include clk: imx25: print silicon revision during init 2023-08-14 12:41:05 +03:00
init Kbuild updates for v6.5 2023-07-01 09:24:31 -07:00
io_uring io_uring-6.5-2023-07-03 2023-07-03 18:43:10 -07:00
ipc Merge branch 'work.namespace' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2023-02-24 19:20:07 -08:00
kernel dma-mapping fixes for Linux 6.5 2023-07-09 10:24:22 -07:00
lib 16 hotfixes. Six are cc:stable and the remainder address post-6.4 issues. 2023-07-08 14:30:25 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm mm: lock newly mapped VMA with corrected ordering 2023-07-08 16:44:11 -07:00
net Including fixes from bluetooth, bpf and wireguard. 2023-07-05 15:44:45 -07:00
rust rust: error: impl Debug for Error with errname() integration 2023-06-13 01:24:42 +02:00
samples Including fixes from bluetooth, bpf and wireguard. 2023-07-05 15:44:45 -07:00
scripts A half-dozen late arriving docs patches. They are mostly fixes, but we 2023-07-06 22:15:38 -07:00
security + Bug Fixes 2023-07-07 09:55:31 -07:00
sound sound fixes for 6.5-rc1 2023-07-07 15:40:17 -07:00
tools perf tools changes and fixes for v6.5: 2nd batch 2023-07-08 10:21:51 -07:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt ARM64: 2023-07-03 15:32:22 -07:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Revert ".gitignore: ignore *.cover and *.mbx" 2023-07-04 15:05:12 -07:00
.mailmap 16 hotfixes. Six are cc:stable and the remainder address post-6.4 issues. 2023-07-08 14:30:25 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS - Address -Wmissing-prototype warnings 2023-06-26 16:43:54 -07:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS 2: Electric Boogaloo 2023-07-09 10:29:53 -07:00
Makefile Linux 6.5-rc1 2023-07-09 13:53:13 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.