Re: [PATCH] clk: Fix invalid execution of clk_set_rate

[Aishwarya TCV <aishwarya.tcv@arm.com>]

On 10/09/2024 06:53, Chuan Liu via B4 Relay wrote:
> From: Chuan Liu <chuan.liu@amlogic.com>
> 
> Some clocks have rates that can be changed elsewhere, so add a flag
> CLK_GET_RATE_NOCACHE(such as scmi_clk) to these clocks to ensure that
> the real-time rate is obtained.
> 
> When clk_set_rate is called, it is returned if the request to set rate
> is consistent with the current rate. Getting the current rate in
> clk_set_rate returns the rate stored in clk_core. CLK_GET_RATE_NOCACHE
> does not take effect here.
> 
> Signed-off-by: Chuan Liu <chuan.liu@amlogic.com>
> ---

Hi Chaun,

Currently, when booting the kernel against next-master (next-20241128)
with Arm64 on the Qualcomm RB5 board, the following logs are printed
repeatedly. This issue does not cause a failure.

A bisect (full log provided below) identified this patch as the source
of the log prints. The bisect was performed on the tag "next-20241118"
in the repository located at
"https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git".

This works fine on Linux 6.12


Sample log from run on RB5:
------
<3>[   17.159611] cpu cpu7: _opp_config_clk_single: failed to set clock
rate: -22
<3>[   17.165534] cpu cpu4: _opp_config_clk_single: failed to set clock
rate: -22
<3>[   17.169338] cpu cpu0: _opp_config_clk_single: failed to set clock
rate: -22
<3>[   17.171850] cpu cpu7: _opp_config_clk_single: failed to set clock
rate: -22
<3>[   17.171913] cpu cpu0: _opp_config_clk_single: failed to set clock
rate: -22
<3>[   17.196804] cpu cpu4: _opp_config_clk_single: failed to set clock
rate: -22

------


Bisect log:
------
git bisect start
# good: [adc218676eef25575469234709c2d87185ca223a] Linux 6.12
git bisect good adc218676eef25575469234709c2d87185ca223a
# bad: [ae58226b89ac0cffa05ba7357733776542e40216] Add linux-next
specific files for 20241118
git bisect bad ae58226b89ac0cffa05ba7357733776542e40216
# bad: [864039014c6a549c57796b83f99cc7fe25bf1afe] Merge branch 'main' of
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git
git bisect bad 864039014c6a549c57796b83f99cc7fe25bf1afe
# bad: [50c7979120c4cff994ea6eaf14747bb0c01a0cd0] Merge branch
'xtensa-for-next' of git://github.com/jcmvbkbc/linux-xtensa.git
git bisect bad 50c7979120c4cff994ea6eaf14747bb0c01a0cd0
# good: [daa20223dee942ebea45bc72b517480af226c370] soc: document merges
git bisect good daa20223dee942ebea45bc72b517480af226c370
# good: [5cc2c18659e40c5d2f93d429d2a4a38234184767] Merge branch
'for-next/core' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
git bisect good 5cc2c18659e40c5d2f93d429d2a4a38234184767
# bad: [618a651f965804164b2f8c446d729197a5fdfd3e] Merge branch
'linux-next' of git://github.com/c-sky/csky-linux.git
git bisect bad 618a651f965804164b2f8c446d729197a5fdfd3e
# good: [d3faed6e9d54a50ad2c505df7e9455752405888c] Merge branch
'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/krzk/linux.git
git bisect good d3faed6e9d54a50ad2c505df7e9455752405888c
# good: [44ea50e086eb287f923460c0119b95d263ec76de] Merge branch
'clk-imx' into clk-next
git bisect good 44ea50e086eb287f923460c0119b95d263ec76de
# good: [ae7a050d03ca95e8e57bc709af8c5a56d1c1b216] Merge branch
'clk-mediatek' into clk-next
git bisect good ae7a050d03ca95e8e57bc709af8c5a56d1c1b216
# bad: [d6c3666ba425fc5a1a4c938591e89279203a25e1] Merge branch
'clk-cleanup' into clk-next
git bisect bad d6c3666ba425fc5a1a4c938591e89279203a25e1
# good: [7b51444e86d11a346c338a03e96d142fc82b95ac] Merge branch
'clk-adi' into clk-next
git bisect good 7b51444e86d11a346c338a03e96d142fc82b95ac
# good: [5e01124a2c0a42dc6b587b0b09b204a5389f8d7b] clk: eyeq: add EyeQ5
fixed factor clocks
git bisect good 5e01124a2c0a42dc6b587b0b09b204a5389f8d7b
# good: [caabff73ef137ff183e4f6626332eb6b0a886522] Merge branch
'clk-mobileye' into clk-next
git bisect good caabff73ef137ff183e4f6626332eb6b0a886522
# bad: [eb70c83178b25e8d7934c51ba6f1b04da2867265] clk: Fix invalid
execution of clk_set_rate
git bisect bad eb70c83178b25e8d7934c51ba6f1b04da2867265
# good: [ac678a1810665f9820934b89157094afd0975a80] clk: clk-loongson2:
Fix memory corruption bug in struct loongson2_clk_provider
git bisect good ac678a1810665f9820934b89157094afd0975a80
# first bad commit: [eb70c83178b25e8d7934c51ba6f1b04da2867265] clk: Fix
invalid execution of clk_set_rate
------

Thanks,
Aishwarya