On Mon, Aug 4, 2025 at 1:15 PM Dan Carpenter <dan.carpen...@linaro.org> wrote:
>
> On Mon, Aug 04, 2025 at 11:08:57AM -0400, Alex Deucher wrote:
> > On Mon, Aug 4, 2025 at 10:49 AM Dan Carpenter <dan.carpen...@linaro.org>
> > wrote:
> > >
> > > On Mon, Aug 04, 2025 at 10:32:43AM -0400, Alex Deucher wrote:
> > > > On Sat, Aug 2, 2025 at 4:22 AM Ethan Carter Edwards
> > > > <et...@ethancedwards.com> wrote:
> > > > >
> > > > > The repeated checks on grbm_soft_reset are unnecessary. Remove them.
> > > > >
> > > >
> > > > These are not NULL checks and they are necessary. The code is
> > > > checking if any bits are set in that register. If not, then we can
> > > > skip that code as there is nothing to do.
> > > >
> > >
> > > It's not a null check, but it is a nested check and it's a local
> > > variable so the patch is correct enough. At this point we know that
> > > grbm_soft_reset can't be zero.
> >
> > It can be 0 as far as I can see. If none of the GRBM_STATUS bits are
> > set, then we never set any of the bits in grbm_soft_reset.
> >
>
> You're missing the first check...
>
> drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
> 7657 if (grbm_soft_reset) {
> ^^^^^^^^^^^^^^^
> Checked.
>
> 7658 /* stop the rlc */
> 7659 gfx_v10_0_rlc_stop(adev);
> 7660
> 7661 /* Disable GFX parsing/prefetching */
> 7662 gfx_v10_0_cp_gfx_enable(adev, false);
> 7663
> 7664 /* Disable MEC parsing/prefetching */
> 7665 gfx_v10_0_cp_compute_enable(adev, false);
> 7666
> 7667 if (grbm_soft_reset) {
> ^^^^^^^^^^^^^^^
> Unnecessary.
Yes, sorry, my brain processed this as the first check.
Alex
>
> 7668 tmp = RREG32_SOC15(GC, 0, mmGRBM_SOFT_RESET);
> 7669 tmp |= grbm_soft_reset;
> 7670 dev_info(adev->dev,
> "GRBM_SOFT_RESET=0x%08X\n", tmp);
> 7671 WREG32_SOC15(GC, 0, mmGRBM_SOFT_RESET, tmp);
> 7672 tmp = RREG32_SOC15(GC, 0, mmGRBM_SOFT_RESET);
> 7673
> 7674 udelay(50);
> 7675
> 7676 tmp &= ~grbm_soft_reset;
> 7677 WREG32_SOC15(GC, 0, mmGRBM_SOFT_RESET, tmp);
> 7678 tmp = RREG32_SOC15(GC, 0, mmGRBM_SOFT_RESET);
> 7679 }
> 7680
> 7681 /* Wait a little for things to settle down */
> 7682 udelay(50);
> 7683 }
> 7684 return 0;
>
> regards,
> dan carpenter
>
