The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 56342da3d8cc15efe9df7f29985ba8d256bdc258 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024062453-fretted-sulfur-3c0f@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 56342da3d8cc15efe9df7f29985ba8d256bdc258 Mon Sep 17 00:00:00 2001 From: Hamza Mahfooz hamza.mahfooz@amd.com Date: Mon, 3 Jun 2024 10:16:45 -0400 Subject: [PATCH] drm/amd/display: prevent register access while in IPS

We can't read/write to DCN registers while in IPS. Since, that can cause the system to hang. So, before proceeding with the access in that scenario, force the system out of IPS.

Cc: stable@vger.kernel.org # 6.6+ Reviewed-by: Roman Li roman.li@amd.com Signed-off-by: Hamza Mahfooz hamza.mahfooz@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index e426adf95d7d..e9ac20bed0f2 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -11437,6 +11437,12 @@ void amdgpu_dm_trigger_timing_sync(struct drm_device *dev) mutex_unlock(&adev->dm.dc_lock); }

+static inline void amdgpu_dm_exit_ips_for_hw_access(struct dc *dc) +{ + if (dc->ctx->dmub_srv && !dc->ctx->dmub_srv->idle_exit_counter) + dc_exit_ips_for_hw_access(dc); +} + void dm_write_reg_func(const struct dc_context *ctx, uint32_t address, u32 value, const char *func_name) { @@ -11447,6 +11453,8 @@ void dm_write_reg_func(const struct dc_context *ctx, uint32_t address, return; } #endif + + amdgpu_dm_exit_ips_for_hw_access(ctx->dc); cgs_write_register(ctx->cgs_device, address, value); trace_amdgpu_dc_wreg(&ctx->perf_trace->write_count, address, value); } @@ -11470,6 +11478,8 @@ uint32_t dm_read_reg_func(const struct dc_context *ctx, uint32_t address, return 0; }

+ amdgpu_dm_exit_ips_for_hw_access(ctx->dc); + value = cgs_read_register(ctx->cgs_device, address);

trace_amdgpu_dc_rreg(&ctx->perf_trace->read_count, address, value);