kernel/linux.git/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c, branch v6.6.142

drm/amdgpu: fix AMDGPU_INFO_READ_MMR_REG

2026-05-23T11:03:27+00:00

[ Upstream commit 0ef196a208385b7d7da79f411c161b04e97283e2 ] There were multiple issues in that code. First of all the order between the reset semaphore and the mm_lock was wrong (e.g. copy_to_user) was called while holding the lock. Then we allocated memory while holding the reset semaphore which is also a pretty big bug and can deadlock. Then we used down_read_trylock() instead of waiting for the reset to finish. Signed-off-by: Christian König Fixes: 9e823f307074 ("drm/amdgpu: Block MMR_READ IOCTL in reset") Reviewed-by: Alex Deucher Signed-off-by: Alex Deucher (cherry picked from commit 361b6e6b303d4b691f6c5974d3eaab67ca6dd90e) Signed-off-by: Sasha Levin

drm/amd: Set num IP blocks to 0 if discovery fails

2026-03-25T10:05:53+00:00

commit 3646ff28780b4c52c5b5081443199e7a430110e5 upstream. If discovery has failed for any reason (such as no support for a block) then there is no need to unwind all the IP blocks in fini. In this condition there can actually be failures during the unwind too. Reset num_ip_blocks to zero during failure path and skip the unnecessary cleanup path. Suggested-by: Lijo Lazar Reviewed-by: Lijo Lazar Signed-off-by: Mario Limonciello Signed-off-by: Alex Deucher (cherry picked from commit fae5984296b981c8cc3acca35b701c1f332a6cd8) Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

drm/amdgpu: Fix NULL pointer dereference in VRAM logic for APU devices

2025-11-24T09:29:57+00:00

[ Upstream commit 883f309add55060233bf11c1ea6947140372920f ] Previously, APU platforms (and other scenarios with uninitialized VRAM managers) triggered a NULL pointer dereference in `ttm_resource_manager_usage()`. The root cause is not that the `struct ttm_resource_manager *man` pointer itself is NULL, but that `man->bdev` (the backing device pointer within the manager) remains uninitialized (NULL) on APUs—since APUs lack dedicated VRAM and do not fully set up VRAM manager structures. When `ttm_resource_manager_usage()` attempts to acquire `man->bdev->lru_lock`, it dereferences the NULL `man->bdev`, leading to a kernel OOPS. 1. **amdgpu_cs.c**: Extend the existing bandwidth control check in `amdgpu_cs_get_threshold_for_moves()` to include a check for `ttm_resource_manager_used()`. If the manager is not used (uninitialized `bdev`), return 0 for migration thresholds immediately—skipping VRAM-specific logic that would trigger the NULL dereference. 2. **amdgpu_kms.c**: Update the `AMDGPU_INFO_VRAM_USAGE` ioctl and memory info reporting to use a conditional: if the manager is used, return the real VRAM usage; otherwise, return 0. This avoids accessing `man->bdev` when it is NULL. 3. **amdgpu_virt.c**: Modify the vf2pf (virtual function to physical function) data write path. Use `ttm_resource_manager_used()` to check validity: if the manager is usable, calculate `fb_usage` from VRAM usage; otherwise, set `fb_usage` to 0 (APUs have no discrete framebuffer to report). This approach is more robust than APU-specific checks because it: - Works for all scenarios where the VRAM manager is uninitialized (not just APUs), - Aligns with TTM's design by using its native helper function, - Preserves correct behavior for discrete GPUs (which have fully initialized `man->bdev` and pass the `ttm_resource_manager_used()` check). v4: use ttm_resource_manager_used(&adev->mman.vram_mgr.manager) instead of checking the adev->gmc.is_app_apu flag (Christian) Reviewed-by: Christian König Suggested-by: Lijo Lazar Signed-off-by: Jesse Zhang Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin

drm/amdgpu: Block MMR_READ IOCTL in reset

2024-10-10T09:57:37+00:00

[ Upstream commit 9e823f307074c0f82b5f6044943b0086e3079bed ] Register access from userspace should be blocked until reset is complete. Signed-off-by: Victor Skvortsov Reviewed-by: Alex Deucher Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin

drm/amdgpu: fall back to INPUT power for AVG power via INFO IOCTL

2024-01-25T23:35:58+00:00

[ Upstream commit d02069850fc102b07ae923535d5e212f2c8a34e9 ] For backwards compatibility with userspace. Fixes: 47f1724db4fe ("drm/amd: Introduce `AMDGPU_PP_SENSOR_GPU_INPUT_POWER`") Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2897 Reviewed-by: Yang Wang Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin

drm/amdgpu: Handle null atom context in VBIOS info ioctl

2023-09-11T22:25:26+00:00

On some APU systems, there is no atom context and so the atom_context struct is null. Add a check to the VBIOS_INFO branch of amdgpu_info_ioctl to handle this case, returning all zeroes. Reviewed-by: Alex Deucher Signed-off-by: David Francis Signed-off-by: Alex Deucher

drm/amdgpu: Store CU info from all XCCs for GFX v9.4.3

2023-09-11T22:16:31+00:00

Currently, we store CU info only for a single XCC assuming that it is the same for all XCCs. However, that may not be true. As a result, store CU info for all XCCs. This info is later used for CU masking. Signed-off-by: Mukul Joshi Reviewed-by: Felix Kuehling Signed-off-by: Alex Deucher

drm/amd: Rename AMDGPU_PP_SENSOR_GPU_POWER

2023-08-15T22:08:30+00:00

Use the clearer name `AMDGPU_PP_SENSOR_GPU_AVG_POWER` instead. Signed-off-by: Mario Limonciello Reviewed-by: Alex Deucher Signed-off-by: Alex Deucher

drm/amdgpu: Update min() to min_t() in 'amdgpu_info_ioctl'

2023-07-25T17:47:26+00:00

Fixes the following: WARNING: min() should probably be min_t(size_t, size, sizeof(ip)) + ret = copy_to_user(out, &ip, min((size_t)size, sizeof(ip))); And other style fixes: WARNING: Prefer 'unsigned int' to bare use of 'unsigned' WARNING: Missing a blank line after declarations Cc: Christian König Cc: Alex Deucher Signed-off-by: Srinivasan Shanmugam Reviewed-by: Alex Deucher Signed-off-by: Alex Deucher

drm/amd: Avoid reading the VBIOS part number twice

2023-07-21T20:52:24+00:00

The VBIOS part number is read both in amdgpu_atom_parse() as well as in atom_get_vbios_pn() and stored twice in the `struct atom_context` structure. Remove the first unnecessary read and move the `pr_info` line from that read into the second. v2: squash in unused variable removal Signed-off-by: Mario Limonciello Reviewed-by: Alex Deucher Signed-off-by: Alex Deucher