From 277b967829aad7b24327f246087805078a62076e Mon Sep 17 00:00:00 2001 From: Konrad Dybcio Date: Fri, 16 Jun 2023 01:20:49 +0200 Subject: [PATCH] drm/msm/a6xx: Add a helper for software-resetting the GPU Introduce a6xx_gpu_sw_reset() in preparation for adding GMU wrapper GPUs and reuse it in a6xx_gmu_force_off(). This helper, contrary to the original usage in GMU code paths, adds a readback+delay sequence to ensure that the reset is never deasserted too quickly due to e.g. OoO execution going crazy. Signed-off-by: Konrad Dybcio Patchwork: https://patchwork.freedesktop.org/patch/542758/ Signed-off-by: Rob Clark --- drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 3 +-- drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 12 ++++++++++++ drivers/gpu/drm/msm/adreno/a6xx_gpu.h | 1 + 3 files changed, 14 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c index 6402544..906bed4 100644 --- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c +++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c @@ -899,8 +899,7 @@ static void a6xx_gmu_force_off(struct a6xx_gmu *gmu) a6xx_bus_clear_pending_transactions(adreno_gpu, true); /* Reset GPU core blocks */ - gpu_write(gpu, REG_A6XX_RBBM_SW_RESET_CMD, 1); - udelay(100); + a6xx_gpu_sw_reset(gpu, true); } static void a6xx_gmu_set_initial_freq(struct msm_gpu *gpu, struct a6xx_gmu *gmu) diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c index d5bd008..b627be3 100644 --- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c +++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c @@ -1742,6 +1742,18 @@ void a6xx_bus_clear_pending_transactions(struct adreno_gpu *adreno_gpu, bool gx_ gpu_write(gpu, REG_A6XX_GBIF_HALT, 0x0); } +void a6xx_gpu_sw_reset(struct msm_gpu *gpu, bool assert) +{ + gpu_write(gpu, REG_A6XX_RBBM_SW_RESET_CMD, assert); + /* Perform a bogus read and add a brief delay to ensure ordering. */ + gpu_read(gpu, REG_A6XX_RBBM_SW_RESET_CMD); + udelay(1); + + /* The reset line needs to be asserted for at least 100 us */ + if (assert) + udelay(100); +} + static int a6xx_pm_resume(struct msm_gpu *gpu) { struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu); diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.h b/drivers/gpu/drm/msm/adreno/a6xx_gpu.h index 9580def..aa70390 100644 --- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.h +++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.h @@ -89,5 +89,6 @@ struct msm_gpu_state *a6xx_gpu_state_get(struct msm_gpu *gpu); int a6xx_gpu_state_put(struct msm_gpu_state *state); void a6xx_bus_clear_pending_transactions(struct adreno_gpu *adreno_gpu, bool gx_off); +void a6xx_gpu_sw_reset(struct msm_gpu *gpu, bool assert); #endif /* __A6XX_GPU_H__ */ -- 2.7.4