Re: [git pull] drm for 5.15-rc1

From: Alex Deucher
Date: Wed Sep 01 2021 - 14:51:53 EST


On Wed, Sep 1, 2021 at 2:33 PM Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> On Wed, Sep 1, 2021 at 10:57 AM Linus Torvalds
> <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> >
> > No worries. I enjoyed seeing the AMD code-names in the conflicts, they
> > are using positively kernel-level naming.
>
> Oh, I spoke too soon.
>
> The conflict in amdgpu_ras_eeprom.c is trivial to fix up, but the
> *code* is garbage.
>
> It does this (from commit 14fb496a84f1: "drm/amdgpu: set RAS EEPROM
> address from VBIOS"):
>
> ...
> control->i2c_address = 0;
>
> if (amdgpu_atomfirmware_ras_rom_addr(adev,
> (uint8_t*)&control->i2c_address))
> {
> if (control->i2c_address == 0xA0)
> control->i2c_address = 0;
> ...
>
> and honestly, that just hurts to look at. It's completely wrong, even
> if it happens to work on a little-endian machine.
>
> Yes, yes, BE is irrelevant, and doubly so for an AMD GPU driver, but still.
>
> It's assigning a 8-bit value to a 32-bit entity by doing a pointer
> cast on the address, and then mixing things up by using/assigning to
> that same field.
>
> That's just *wrong* and nasty.
>
> Oh, the resolution would be easy - just take that broken code as-is -
> but I can't actually make myself do that.
>
> So I fixed it up to not be that incredibly ugly garbage.
>
> Please holler if I did something wrong.

Fix looks good. Thanks,

Alex