Am 06.04.22 um 16:26 schrieb Jani Nikula:
On Tue, 05 Apr 2022, Christian König <christian.koenig@xxxxxxx> 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".
Well to me it is an absolute miracle why the heck compilers don't
initialize paddings.
We had so many ups moments over the years and I really don't see why it
should be more optimal to do this.
Anyway, the memset() is used intentionally here and I don't really want
to change it. What we could do is removing the second superfluous memset
and use sizeof() instead of hard coding the size.
Regards,
Christian.
*shrug*
BR,
Jani.
So please don't use {0} in any of the atom bios code.
Regards,
Christian.
Signed-off-by: Grigory Vasilyev <h0tc0d3@xxxxxxxxx>
---
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;
}
