Re: [PATCH v3 3/5] drm/xe/hwmon: Fix memory controller thermal data handling

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Thu, Sep 10, 2026 at 11:57:54PM +0530, Karthik Poosa wrote:
> Read all required thermal groups in get_mc_temp() and use an aligned
> u32 buffer for PCODE accesses to avoid unaligned memory accesses and
> ensure correct MC temperature reporting.
> 
> Signed-off-by: Karthik Poosa <karthik.poosa@intel.com>
> Fixes: 3a0cb885e111 ("drm/xe/hwmon: Expose memory controller temperature")

please move this to be the first patch of the series or send this
standalone.

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

> ---
>  drivers/gpu/drm/xe/xe_hwmon.c | 16 ++++++++++------
>  1 file changed, 10 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_hwmon.c b/drivers/gpu/drm/xe/xe_hwmon.c
> index a60a6a731d88..c682c5a33650 100644
> --- a/drivers/gpu/drm/xe/xe_hwmon.c
> +++ b/drivers/gpu/drm/xe/xe_hwmon.c
> @@ -148,8 +148,12 @@ struct xe_hwmon_thermal_info {
>  	u8 count;
>  	/** @vram_count: number of VRAM temperature sensors available for the platform */
>  	u8 vram_count;
> -	/** @value: signed value from each sensor */
> -	s8 value[U8_MAX];
> +	union {
> +		/** @value: signed value from each sensor */
> +		s8 value[U8_MAX + 1];
> +		/** @dword: sensor values as dwords, u32-aligned for pcode reads */
> +		u32 dword[DIV_ROUND_UP(U8_MAX + 1, sizeof(u32))];
> +	};
>  	/** @vram_label: vram label names, dynamically allocated based on vram_count */
>  	char (*vram_label)[MAX_LABEL_SIZE];
>  };
> @@ -910,16 +914,16 @@ static inline bool is_temp_valid(const struct xe_hwmon *hwmon, u32 value, bool i
>  static int get_mc_temp(struct xe_hwmon *hwmon, long *val)
>  {
>  	struct xe_tile *root_tile = xe_device_get_root_tile(hwmon->xe);
> -	u32 *dword = (u32 *)hwmon->temp.value;
>  	int ret, i, count = 0;
>  	s32 average = 0;
>  
> -	for (i = 0; i < DIV_ROUND_UP(TEMP_LIMIT_MAX, sizeof(u32)); i++) {
> +	for (i = 0; i < DIV_ROUND_UP(hwmon->temp.count, sizeof(u32)); i++) {
>  		ret = xe_pcode_read(root_tile, PCODE_MBOX(PCODE_THERMAL_INFO, READ_THERMAL_DATA, i),
> -				    (dword + i), NULL);
> +				    &hwmon->temp.dword[i], NULL);
>  		if (ret)
>  			return ret;
> -		drm_dbg(&hwmon->xe->drm, "thermal data for group %d val 0x%x\n", i, dword[i]);
> +		drm_dbg(&hwmon->xe->drm, "thermal data for group %d val 0x%x\n", i,
> +			hwmon->temp.dword[i]);
>  	}
>  
>  	for (i = TEMP_INDEX_MCTRL; i < hwmon->temp.count - 1; i++) {
> -- 
> 2.25.1
>