Re: [PATCH 2/4] drm/msm/a6xx: Fix GMU firmware parser

[Akhil P Oommen <akhilpo@oss.qualcomm.com>]

On 9/2/2025 5:59 PM, Konrad Dybcio wrote:
> On 9/2/25 1:50 PM, Akhil P Oommen wrote:
>> Current parser logic for GMU firmware assumes a dword aligned payload
>> size for every block. This is not true for all GMU firmwares. So, fix
>> this by using correct 'size' value in the calculation for the offset
>> for the next block's header.
> 
> Hm, I haven't seen this in the wild - do you have any specific examples?

I saw this in an unreleased chipset's fw. But felt it might show up in
newer gmu fw versions of older chipsets too.

> 
>>
>> Fixes: c6ed04f856a4 ("drm/msm/a6xx: A640/A650 GMU firmware path")
>> Signed-off-by: Akhil P Oommen <akhilpo@oss.qualcomm.com>
>> ---
>>  drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 4 +++-
>>  1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>> index 28e6705c6da682c7b41c748e375dda59a6551898..ea52374c9fcd481d816ed9608e9f6eb1c2e3005a 100644
>> --- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>> @@ -758,6 +758,8 @@ static bool fw_block_mem(struct a6xx_gmu_bo *bo, const struct block_header *blk)
>>  	return true;
>>  }
>>  
>> +#define NEXT_BLK(blk) ((const struct block_header *)((const char *)blk + sizeof(*blk) + blk->size))
> 
> CHECK: Macro argument 'blk' may be better as '(blk)' to avoid precedence issues
> #146: FILE: drivers/gpu/drm/msm/adreno/a6xx_gmu.c:761:
> +#define NEXT_BLK(blk) ((const struct block_header *)((const char *)blk + sizeof(*blk) + blk->size))

Ack. Thanks.

-Akhil.

> 
> Konrad