On Tue, 05 Apr 2022, Christian König <[email protected]> wrote:
> Am 05.04.22 um 19:36 schrieb Grigory Vasilyev:
>> Using memset on local arrays before exiting the function is pointless.
>> Compilator will remove this code. Also for local arrays is preferable to
>> use {0} instead of memset. Mistakes are often made when working with
>> memset.
>
> Well actually memset is preferred when working with structures which are
> given to the hardware parser because {0} won't initialize paddings.
Not that I'd know anything that's going on here... but it sure seems
strange to me to be passing unpacked structures where the padding might
matter to a "hardware parser".
*shrug*
BR,
Jani.
>
> So please don't use {0} in any of the atom bios code.
>
> Regards,
> Christian.
>
>>
>> Signed-off-by: Grigory Vasilyev <[email protected]>
>> ---
>> drivers/gpu/drm/amd/amdgpu/atom.c | 8 +-------
>> 1 file changed, 1 insertion(+), 7 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/atom.c
>> b/drivers/gpu/drm/amd/amdgpu/atom.c
>> index be9d61bcb8ae..537e48fbbe6b 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/atom.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/atom.c
>> @@ -1538,11 +1538,9 @@ struct atom_context *amdgpu_atom_parse(struct
>> card_info *card, void *bios)
>> int amdgpu_atom_asic_init(struct atom_context *ctx)
>> {
>> int hwi = CU16(ctx->data_table + ATOM_DATA_FWI_PTR);
>> - uint32_t ps[16];
>> + uint32_t ps[16] = {0};
>> int ret;
>>
>> - memset(ps, 0, 64);
>> -
>> ps[0] = cpu_to_le32(CU32(hwi + ATOM_FWI_DEFSCLK_PTR));
>> ps[1] = cpu_to_le32(CU32(hwi + ATOM_FWI_DEFMCLK_PTR));
>> if (!ps[0] || !ps[1])
>> @@ -1551,10 +1549,6 @@ int amdgpu_atom_asic_init(struct atom_context *ctx)
>> if (!CU16(ctx->cmd_table + 4 + 2 * ATOM_CMD_INIT))
>> return 1;
>> ret = amdgpu_atom_execute_table(ctx, ATOM_CMD_INIT, ps);
>> - if (ret)
>> - return ret;
>> -
>> - memset(ps, 0, 64);
>>
>> return ret;
>> }
>
--
Jani Nikula, Intel Open Source Graphics Center
