This is a note to let you know that I've just added the patch titled drm/etnaviv: hold GPU lock across perfmon sampling to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-etnaviv-hold-gpu-lock-across-perfmon-sampling.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit d1badabd1577c305dece4a183956db478fcaccad Author: Lucas Stach <l.stach@xxxxxxxxxxxxxx> Date: Fri Jul 5 22:00:09 2024 +0200 drm/etnaviv: hold GPU lock across perfmon sampling [ Upstream commit 37dc4737447a7667f8e9ec790dac251da057eb27 ] The perfmon sampling mutates shared GPU state (e.g. VIVS_HI_CLOCK_CONTROL to select the pipe for the perf counter reads). To avoid clashing with other functions mutating the same state (e.g. etnaviv_gpu_update_clock) the perfmon sampling needs to hold the GPU lock. Fixes: 68dc0b295dcb ("drm/etnaviv: use 'sync points' for performance monitor requests") Reviewed-by: Christian Gmeiner <cgmeiner@xxxxxxxxxx> Signed-off-by: Lucas Stach <l.stach@xxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c index 9def75f04e5b6..0fff51dc97755 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c +++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c @@ -1292,6 +1292,8 @@ static void sync_point_perfmon_sample_pre(struct etnaviv_gpu *gpu, { u32 val; + mutex_lock(&gpu->lock); + /* disable clock gating */ val = gpu_read_power(gpu, VIVS_PM_POWER_CONTROLS); val &= ~VIVS_PM_POWER_CONTROLS_ENABLE_MODULE_CLOCK_GATING; @@ -1303,6 +1305,8 @@ static void sync_point_perfmon_sample_pre(struct etnaviv_gpu *gpu, gpu_write(gpu, VIVS_HI_CLOCK_CONTROL, val); sync_point_perfmon_sample(gpu, event, ETNA_PM_PROCESS_PRE); + + mutex_unlock(&gpu->lock); } static void sync_point_perfmon_sample_post(struct etnaviv_gpu *gpu, @@ -1312,13 +1316,9 @@ static void sync_point_perfmon_sample_post(struct etnaviv_gpu *gpu, unsigned int i; u32 val; - sync_point_perfmon_sample(gpu, event, ETNA_PM_PROCESS_POST); - - for (i = 0; i < submit->nr_pmrs; i++) { - const struct etnaviv_perfmon_request *pmr = submit->pmrs + i; + mutex_lock(&gpu->lock); - *pmr->bo_vma = pmr->sequence; - } + sync_point_perfmon_sample(gpu, event, ETNA_PM_PROCESS_POST); /* disable debug register */ val = gpu_read(gpu, VIVS_HI_CLOCK_CONTROL); @@ -1329,6 +1329,14 @@ static void sync_point_perfmon_sample_post(struct etnaviv_gpu *gpu, val = gpu_read_power(gpu, VIVS_PM_POWER_CONTROLS); val |= VIVS_PM_POWER_CONTROLS_ENABLE_MODULE_CLOCK_GATING; gpu_write_power(gpu, VIVS_PM_POWER_CONTROLS, val); + + mutex_unlock(&gpu->lock); + + for (i = 0; i < submit->nr_pmrs; i++) { + const struct etnaviv_perfmon_request *pmr = submit->pmrs + i; + + *pmr->bo_vma = pmr->sequence; + } }