On Fri, Jul 17, 2020 at 08:04:18PM +0530, Akhil P Oommen wrote:
> On targets where GMU is available, GMU takes over the ownership of GX GDSC
> during its initialization. So, move the refcount-get on GX PD before we
> initialize the GMU. This ensures that nobody can collapse the GX GDSC
> once GMU owns the GX GDSC. This patch fixes some GMU OOB errors seen
> during GPU wake up during a system resume.
> Signed-off-by: Akhil P Oommen <akhilpo@xxxxxxxxxxxxxx>
> Reported-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
> Tested-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
The Signed-off-by needs to be at the end but I think Rob can do that for you.
Reviewed-by: Jordan Crouse <jcrouse@xxxxxxxxxxxxxx>
> ---
> Changes from v1:
> - Reworded the commit text
> - Added Reported-by & Tested-by tags
>
> drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 18 ++++++++++--------
> 1 file changed, 10 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
> index 21e77d6..1d33020 100644
> --- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
> @@ -854,10 +854,19 @@ int a6xx_gmu_resume(struct a6xx_gpu *a6xx_gpu)
> /* Turn on the resources */
> pm_runtime_get_sync(gmu->dev);
>
> + /*
> + * "enable" the GX power domain which won't actually do anything but it
> + * will make sure that the refcounting is correct in case we need to
> + * bring down the GX after a GMU failure
> + */
> + if (!IS_ERR_OR_NULL(gmu->gxpd))
> + pm_runtime_get_sync(gmu->gxpd);
> +
> /* Use a known rate to bring up the GMU */
> clk_set_rate(gmu->core_clk, 200000000);
> ret = clk_bulk_prepare_enable(gmu->nr_clocks, gmu->clocks);
> if (ret) {
> + pm_runtime_put(gmu->gxpd);
> pm_runtime_put(gmu->dev);
> return ret;
> }
> @@ -903,19 +912,12 @@ int a6xx_gmu_resume(struct a6xx_gpu *a6xx_gpu)
> else
> a6xx_hfi_set_freq(gmu, gmu->current_perf_index);
>
> - /*
> - * "enable" the GX power domain which won't actually do anything but it
> - * will make sure that the refcounting is correct in case we need to
> - * bring down the GX after a GMU failure
> - */
> - if (!IS_ERR_OR_NULL(gmu->gxpd))
> - pm_runtime_get(gmu->gxpd);
> -
> out:
> /* On failure, shut down the GMU to leave it in a good state */
> if (ret) {
> disable_irq(gmu->gmu_irq);
> a6xx_rpmh_stop(gmu);
> + pm_runtime_put(gmu->gxpd);
> pm_runtime_put(gmu->dev);
> }
>
> --
> 2.7.4
>
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