On Fri, Aug 15, 2025 at 02:36:23PM +0800, zhaoguo...@kylinos.cn wrote:
> From: GuoHan Zhao <zhaoguo...@kylinos.cn>
>
> In xe_hwmon_pcode_rmw_power_limit(), when xe_pcode_read() fails,
> the function logs the error but continues to execute the subsequent
> logic. This can result in undefined behavior as the values val0 and
> val1 may contain invalid data.
>
> Fix this by adding an early return after logging the read failure,
> ensuring that we don't proceed with potentially corrupted data.
>
> Fixes: 8aa7306631f0 ("drm/xe/hwmon: Fix xe_hwmon_power_max_write")
>
> V2:
> - Change 'drm_dbg' to 'drm_err'
> - Added the Fixes tag in commit message
There are still missed/unanswered questions/concerns in the original review:
https://lore.kernel.org/intel-xe/ajtg0xmbbgwnt...@intel.com
Please ensure to address all of them before re-iterating the patch.
Thanks,
Rodrigo.
>
> Signed-off-by: GuoHan Zhao <zhaoguo...@kylinos.cn>
> ---
> drivers/gpu/drm/xe/xe_hwmon.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/xe/xe_hwmon.c b/drivers/gpu/drm/xe/xe_hwmon.c
> index f08fc4377d25..8e29fa155d7e 100644
> --- a/drivers/gpu/drm/xe/xe_hwmon.c
> +++ b/drivers/gpu/drm/xe/xe_hwmon.c
> @@ -190,9 +190,11 @@ static int xe_hwmon_pcode_rmw_power_limit(const struct
> xe_hwmon *hwmon, u32 attr
> READ_PL_FROM_PCODE :
> READ_PL_FROM_FW),
> &val0, &val1);
>
> - if (ret)
> - drm_dbg(&hwmon->xe->drm, "read failed ch %d val0 0x%08x, val1
> 0x%08x, ret %d\n",
> + if (ret) {
> + drm_err(&hwmon->xe->drm, "read failed ch %d val0 0x%08x, val1
> 0x%08x, ret %d\n",
> channel, val0, val1, ret);
> + return ret;
> + }
>
> if (attr == PL1_HWMON_ATTR)
> val0 = (val0 & ~clr) | set;
> --
> 2.43.0
>
