From 89939cf252d80237ed380c1d20575ecfe56ff894 Mon Sep 17 00:00:00 2001 From: Meenakshikumar Somasundaram Date: Mon, 29 Sep 2025 14:28:34 -0400 Subject: drm/amd/display: Fix NULL pointer dereference [Why] On a mst branch with multi display setup, dc context is obselete after updating the first stream. Referencing the same dc context for the next stream update to fetch dc pointer leads to NULL pointer dereference. [How] Get the dc pointer from the link rather than context. Cc: Mario Limonciello Cc: Alex Deucher Reviewed-by: Charlene Liu Signed-off-by: Meenakshikumar Somasundaram Signed-off-by: Aurabindo Pillai Signed-off-by: Alex Deucher (cherry picked from commit dc69b48988b171d6ccb3a083607e4dff015e2c0d) Cc: stable@vger.kernel.org --- drivers/gpu/drm/amd/display/dc/link/accessories/link_dp_cts.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/gpu/drm/amd/display') diff --git a/drivers/gpu/drm/amd/display/dc/link/accessories/link_dp_cts.c b/drivers/gpu/drm/amd/display/dc/link/accessories/link_dp_cts.c index 9e33bf937a69..2676ae9f6fe8 100644 --- a/drivers/gpu/drm/amd/display/dc/link/accessories/link_dp_cts.c +++ b/drivers/gpu/drm/amd/display/dc/link/accessories/link_dp_cts.c @@ -78,6 +78,7 @@ static void dp_retrain_link_dp_test(struct dc_link *link, struct audio_output audio_output[MAX_PIPES]; struct dc_stream_state *streams_on_link[MAX_PIPES]; int num_streams_on_link = 0; + struct dc *dc = (struct dc *)link->dc; needs_divider_update = (link->dc->link_srv->dp_get_encoding_format(link_setting) != link->dc->link_srv->dp_get_encoding_format((const struct dc_link_settings *) &link->cur_link_settings)); @@ -150,7 +151,7 @@ static void dp_retrain_link_dp_test(struct dc_link *link, if (streams_on_link[i] && streams_on_link[i]->link && streams_on_link[i]->link == link) { stream_update.stream = streams_on_link[i]; stream_update.dpms_off = &dpms_off; - dc_update_planes_and_stream(state->clk_mgr->ctx->dc, NULL, 0, streams_on_link[i], &stream_update); + dc_update_planes_and_stream(dc, NULL, 0, streams_on_link[i], &stream_update); } } } -- cgit v1.2.3 From bec947cbe9a65783adb475a5fb47980d7b4f4796 Mon Sep 17 00:00:00 2001 From: Charlene Liu Date: Mon, 29 Sep 2025 20:29:30 -0400 Subject: drm/amd/display: increase max link count and fix link->enc NULL pointer access [why] 1.) dc->links[MAX_LINKS] array size smaller than actual requested. max_connector + max_dpia + 4 virtual = 14. increase from 12 to 14. 2.) hw_init() access null LINK_ENC for dpia non display_endpoint. Cc: Mario Limonciello Cc: Alex Deucher Reviewed-by: Meenakshikumar Somasundaram Reviewed-by: Chris Park Signed-off-by: Charlene Liu Signed-off-by: Aurabindo Pillai Signed-off-by: Alex Deucher (cherry picked from commit d7f5a61e1b04ed87b008c8d327649d184dc5bb45) Cc: stable@vger.kernel.org --- drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c | 3 +++ drivers/gpu/drm/amd/display/dc/inc/hw/hw_shared.h | 8 +++++++- 2 files changed, 10 insertions(+), 1 deletion(-) (limited to 'drivers/gpu/drm/amd/display') diff --git a/drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c b/drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c index 7c276c319086..ce3d0b45fb4c 100644 --- a/drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c +++ b/drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c @@ -200,6 +200,9 @@ void dcn401_init_hw(struct dc *dc) */ struct dc_link *link = dc->links[i]; + if (link->ep_type != DISPLAY_ENDPOINT_PHY) + continue; + link->link_enc->funcs->hw_init(link->link_enc); /* Check for enabled DIG to identify enabled display */ diff --git a/drivers/gpu/drm/amd/display/dc/inc/hw/hw_shared.h b/drivers/gpu/drm/amd/display/dc/inc/hw/hw_shared.h index 41c76ba9ba56..62a39204fe0b 100644 --- a/drivers/gpu/drm/amd/display/dc/inc/hw/hw_shared.h +++ b/drivers/gpu/drm/amd/display/dc/inc/hw/hw_shared.h @@ -44,7 +44,13 @@ */ #define MAX_PIPES 6 #define MAX_PHANTOM_PIPES (MAX_PIPES / 2) -#define MAX_LINKS (MAX_PIPES * 2 +2) + +#define MAX_DPIA 6 +#define MAX_CONNECTOR 6 +#define MAX_VIRTUAL_LINKS 4 + +#define MAX_LINKS (MAX_DPIA + MAX_CONNECTOR + MAX_VIRTUAL_LINKS) + #define MAX_DIG_LINK_ENCODERS 7 #define MAX_DWB_PIPES 1 #define MAX_HPO_DP2_ENCODERS 4 -- cgit v1.2.3 From 72a1eb3cf573ab957ae412f0efb0cf6ff0876234 Mon Sep 17 00:00:00 2001 From: Aurabindo Pillai Date: Thu, 25 Sep 2025 10:23:59 -0400 Subject: drm/amd/display: use GFP_NOWAIT for allocation in interrupt handler schedule_dc_vmin_vmax() is called by dm_crtc_high_irq(). Hence, we cannot have the former sleep. Use GFP_NOWAIT for allocation in this function. Fixes: c210b757b400 ("drm/amd/display: fix dmub access race condition") Cc: Mario Limonciello Cc: Alex Deucher Reviewed-by: Sun peng (Leo) Li Signed-off-by: Aurabindo Pillai Signed-off-by: Alex Deucher (cherry picked from commit c04812cbe2f247a1c1e53a9b6c5e659963fe4065) Cc: stable@vger.kernel.org --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/gpu/drm/amd/display') 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 6597475e245d..bfa3199591b6 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -551,13 +551,13 @@ static void schedule_dc_vmin_vmax(struct amdgpu_device *adev, struct dc_stream_state *stream, struct dc_crtc_timing_adjust *adjust) { - struct vupdate_offload_work *offload_work = kzalloc(sizeof(*offload_work), GFP_KERNEL); + struct vupdate_offload_work *offload_work = kzalloc(sizeof(*offload_work), GFP_NOWAIT); if (!offload_work) { drm_dbg_driver(adev_to_drm(adev), "Failed to allocate vupdate_offload_work\n"); return; } - struct dc_crtc_timing_adjust *adjust_copy = kzalloc(sizeof(*adjust_copy), GFP_KERNEL); + struct dc_crtc_timing_adjust *adjust_copy = kzalloc(sizeof(*adjust_copy), GFP_NOWAIT); if (!adjust_copy) { drm_dbg_driver(adev_to_drm(adev), "Failed to allocate adjust_copy\n"); kfree(offload_work); -- cgit v1.2.3