kernel/linux.git/drivers/gpu/drm/i915, branch linux-rolling-lts

x86: rename and clean up __copy_from_user_inatomic_nocache()

2026-04-22T11:22:31+00:00

commit 5de7bcaadf160c1716b20a263cf8f5b06f658959 upstream. Similarly to the previous commit, this renames the somewhat confusingly named function. But in this case, it was at least less confusing: the __copy_from_user_inatomic_nocache is indeed copying from user memory, and it is indeed ok to be used in an atomic context, so it will not warn about it. But the previous commit also removed the NTB mis-use of the __copy_from_user_inatomic_nocache() function, and as a result every call-site is now _actually_ doing a real user copy. That means that we can now do the proper user pointer verification too. End result: add proper address checking, remove the double underscores, and change the "nocache" to "nontemporal" to more accurately describe what this x86-only function actually does. It might be worth noting that only the target is non-temporal: the actual user accesses are normal memory accesses. Also worth noting is that non-x86 targets (and on older 32-bit x86 CPU's before XMM2 in the Pentium III) we end up just falling back on a regular user copy, so nothing can actually depend on the non-temporal semantics, but that has always been true. Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

drm/i915/psr: Do not use pipe_src as borders for SU area

2026-04-18T08:44:59+00:00

commit 75519f5df2a9b23f7bf305e12dc9a6e3e65c24b7 upstream. This far using crtc_state->pipe_src as borders for Selective Update area haven't caused visible problems as drm_rect_width(crtc_state->pipe_src) == crtc_state->hw.adjusted_mode.crtc_hdisplay and drm_rect_height(crtc_state->pipe_src) == crtc_state->hw.adjusted_mode.crtc_vdisplay when pipe scaling is not used. On the other hand using pipe scaling is forcing full frame updates and all the Selective Update area calculations are skipped. Now this improper usage of crtc_state->pipe_src is causing following warnings: <4> [7771.978166] xe 0000:00:02.0: [drm] drm_WARN_ON_ONCE(su_lines % vdsc_cfg->slice_height) after WARN_ON_ONCE was added by commit: "drm/i915/dsc: Add helper for writing DSC Selective Update ET parameters" These warnings are seen when DSC and pipe scaling are enabled simultaneously. This is because on full frame update SU area is improperly set as pipe_src which is not aligned with DSC slice height. Fix these by creating local rectangle using crtc_state->hw.adjusted_mode.crtc_hdisplay and crtc_state->hw.adjusted_mode.crtc_vdisplay. Use this local rectangle as borders for SU area. Fixes: d6774b8c3c58 ("drm/i915: Ensure damage clip area is within pipe area") Cc: # v6.0+ Signed-off-by: Jouni Högander Reviewed-by: Mika Kahola Link: https://patch.msgid.link/20260327114553.195285-1-jouni.hogander@intel.com (cherry picked from commit da0cdc1c329dd2ff09c41fbbe9fbd9c92c5d2c6e) Signed-off-by: Joonas Lahtinen Signed-off-by: Greg Kroah-Hartman

drm/i915/gt: fix refcount underflow in intel_engine_park_heartbeat

2026-04-18T08:44:59+00:00

commit 4c71fd099513bfa8acab529b626e1f0097b76061 upstream. A use-after-free / refcount underflow is possible when the heartbeat worker and intel_engine_park_heartbeat() race to release the same engine->heartbeat.systole request. The heartbeat worker reads engine->heartbeat.systole and calls i915_request_put() on it when the request is complete, but clears the pointer in a separate, non-atomic step. Concurrently, a request retirement on another CPU can drop the engine wakeref to zero, triggering __engine_park() -> intel_engine_park_heartbeat(). If the heartbeat timer is pending at that point, cancel_delayed_work() returns true and intel_engine_park_heartbeat() reads the stale non-NULL systole pointer and calls i915_request_put() on it again, causing a refcount underflow: ``` <4> [487.221889] Workqueue: i915-unordered engine_retire [i915] <4> [487.222640] RIP: 0010:refcount_warn_saturate+0x68/0xb0 ... <4> [487.222707] Call Trace: <4> [487.222711] <4> [487.222716] intel_engine_park_heartbeat.part.0+0x6f/0x80 [i915] <4> [487.223115] intel_engine_park_heartbeat+0x25/0x40 [i915] <4> [487.223566] __engine_park+0xb9/0x650 [i915] <4> [487.223973] ____intel_wakeref_put_last+0x2e/0xb0 [i915] <4> [487.224408] __intel_wakeref_put_last+0x72/0x90 [i915] <4> [487.224797] intel_context_exit_engine+0x7c/0x80 [i915] <4> [487.225238] intel_context_exit+0xf1/0x1b0 [i915] <4> [487.225695] i915_request_retire.part.0+0x1b9/0x530 [i915] <4> [487.226178] i915_request_retire+0x1c/0x40 [i915] <4> [487.226625] engine_retire+0x122/0x180 [i915] <4> [487.227037] process_one_work+0x239/0x760 <4> [487.227060] worker_thread+0x200/0x3f0 <4> [487.227068] ? __pfx_worker_thread+0x10/0x10 <4> [487.227075] kthread+0x10d/0x150 <4> [487.227083] ? __pfx_kthread+0x10/0x10 <4> [487.227092] ret_from_fork+0x3d4/0x480 <4> [487.227099] ? __pfx_kthread+0x10/0x10 <4> [487.227107] ret_from_fork_asm+0x1a/0x30 <4> [487.227141] ``` Fix this by replacing the non-atomic pointer read + separate clear with xchg() in both racing paths. xchg() is a single indivisible hardware instruction that atomically reads the old pointer and writes NULL. This guarantees only one of the two concurrent callers obtains the non-NULL pointer and performs the put, the other gets NULL and skips it. Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/work_items/15880 Fixes: 058179e72e09 ("drm/i915/gt: Replace hangcheck by heartbeats") Cc: # v5.5+ Signed-off-by: Sebastian Brzezinka Reviewed-by: Krzysztof Karas Reviewed-by: Andi Shyti Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/d4c1c14255688dd07cc8044973c4f032a8d1559e.1775038106.git.sebastian.brzezinka@intel.com (cherry picked from commit 13238dc0ee4f9ab8dafa2cca7295736191ae2f42) Signed-off-by: Joonas Lahtinen Signed-off-by: Greg Kroah-Hartman

drm/i915/dp: Use crtc_state->enhanced_framing properly on ivb/hsw CPU eDP

2026-04-11T12:26:37+00:00

commit 9c9a57e4e337f94e23ddf69263fd0685c91155fb upstream. Looks like I missed the drm_dp_enhanced_frame_cap() in the ivb/hsw CPU eDP code when I introduced crtc_state->enhanced_framing. Fix it up so that the state we program to the hardware is guaranteed to match what we computed earlier. Cc: stable@vger.kernel.org Fixes: 3072a24c778a ("drm/i915: Introduce crtc_state->enhanced_framing") Signed-off-by: Ville Syrjälä Link: https://patch.msgid.link/20260325135849.12603-3-ville.syrjala@linux.intel.com Reviewed-by: Michał Grzelak (cherry picked from commit 799fe8dc2af52f35c78c4ac97f8e34994dfd8760) Signed-off-by: Joonas Lahtinen Signed-off-by: Greg Kroah-Hartman

drm/i915/dsi: Don't do DSC horizontal timing adjustments in command mode

2026-04-11T12:26:37+00:00

commit 4dfce79e098915d8e5fc2b9e1d980bc3251dd32c upstream. Stop adjusting the horizontal timing values based on the compression ratio in command mode. Bspec seems to be telling us to do this only in video mode, and this is also how the Windows driver does things. This should also fix a div-by-zero on some machines because the adjusted htotal ends up being so small that we end up with line_time_us==0 when trying to determine the vtotal value in command mode. Note that this doesn't actually make the display on the Huawei Matebook E work, but at least the kernel no longer explodes when the driver loads. Cc: stable@vger.kernel.org Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/12045 Signed-off-by: Ville Syrjälä Link: https://patch.msgid.link/20260326111814.9800-2-ville.syrjala@linux.intel.com Fixes: 53693f02d80e ("drm/i915/dsi: account for DSC in horizontal timings") Reviewed-by: Jani Nikula (cherry picked from commit 0b475e91ecc2313207196c6d7fd5c53e1a878525) Signed-off-by: Joonas Lahtinen Signed-off-by: Greg Kroah-Hartman

drm/i915: Unlink NV12 planes earlier

2026-04-02T11:23:24+00:00

commit bfa71b7a9dc6b5b8af157686e03308291141d00c upstream. unlink_nv12_plane() will clobber parts of the plane state potentially already set up by plane_atomic_check(), so we must make sure not to call the two in the wrong order. The problem happens when a plane previously selected as a Y plane is now configured as a normal plane by user space. plane_atomic_check() will first compute the proper plane state based on the userspace request, and unlink_nv12_plane() later clears some of the state. This used to work on account of unlink_nv12_plane() skipping the state clearing based on the plane visibility. But I removed that check, thinking it was an impossible situation. Now when that situation happens unlink_nv12_plane() will just WARN and proceed to clobber the state. Rather than reverting to the old way of doing things, I think it's more clear if we unlink the NV12 planes before we even compute the new plane state. Cc: stable@vger.kernel.org Reported-by: Khaled Almahallawy Closes: https://lore.kernel.org/intel-gfx/20260212004852.1920270-1-khaled.almahallawy@intel.com/ Tested-by: Khaled Almahallawy Fixes: 6a01df2f1b2a ("drm/i915: Remove pointless visible check in unlink_nv12_plane()") Signed-off-by: Ville Syrjälä Link: https://patch.msgid.link/20260316163953.12905-2-ville.syrjala@linux.intel.com Reviewed-by: Uma Shankar (cherry picked from commit 017ecd04985573eeeb0745fa2c23896fb22ee0cc) Signed-off-by: Joonas Lahtinen Signed-off-by: Greg Kroah-Hartman

drm/i915: Order OP vs. timeout correctly in __wait_for()

2026-04-02T11:23:24+00:00

commit 6ad2a661ff0d3d94884947d2a593311ba46d34c2 upstream. Put the barrier() before the OP so that anything we read out in OP and check in COND will actually be read out after the timeout has been evaluated. Currently the only place where we use OP is __intel_wait_for_register(), but the use there is precisely susceptible to this reordering, assuming the ktime_*() stuff itself doesn't act as a sufficient barrier: __intel_wait_for_register(...) { ... ret = __wait_for(reg_value = intel_uncore_read_notrace(...), (reg_value & mask) == value, ...); ... } Cc: stable@vger.kernel.org Fixes: 1c3c1dc66a96 ("drm/i915: Add compiler barrier to wait_for") Signed-off-by: Ville Syrjälä Link: https://patch.msgid.link/20260313110740.24620-1-ville.syrjala@linux.intel.com Reviewed-by: Jani Nikula (cherry picked from commit a464bace0482aa9a83e9aa7beefbaf44cd58e6cf) Signed-off-by: Joonas Lahtinen Signed-off-by: Greg Kroah-Hartman

drm/i915/dp_tunnel: Fix error handling when clearing stream BW in atomic state

2026-04-02T11:23:23+00:00

commit 77fcf58df15edcf3f5b5421f24814fb72796def9 upstream. Clearing the DP tunnel stream BW in the atomic state involves getting the tunnel group state, which can fail. Handle the error accordingly. This fixes at least one issue where drm_dp_tunnel_atomic_set_stream_bw() failed to get the tunnel group state returning -EDEADLK, which wasn't handled. This lead to the ctx->contended warn later in modeset_lock() while taking a WW mutex for another object in the same atomic state, and thus within the same already contended WW context. Moving intel_crtc_state_alloc() later would avoid freeing saved_state on the error path; this stable patch leaves that simplification for a follow-up. Cc: Uma Shankar Cc: Ville Syrjälä Cc: # v6.9+ Fixes: a4efae87ecb2 ("drm/i915/dp: Compute DP tunnel BW during encoder state computation") Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/7617 Reviewed-by: Michał Grzelak Reviewed-by: Uma Shankar Signed-off-by: Imre Deak Link: https://patch.msgid.link/20260320092900.13210-1-imre.deak@intel.com (cherry picked from commit fb69d0076e687421188bc8103ab0e8e5825b1df1) Signed-off-by: Joonas Lahtinen Signed-off-by: Greg Kroah-Hartman

drm/i915/gmbus: fix spurious timeout on 512-byte burst reads

2026-04-02T11:23:13+00:00

[ Upstream commit 08441f10f4dc09fdeb64529953ac308abc79dd38 ] When reading exactly 512 bytes with burst read enabled, the extra_byte_added path breaks out of the inner do-while without decrementing len. The outer while(len) then re-enters and gmbus_wait() times out since all data has been delivered. Decrement len before the break so the outer loop terminates correctly. Fixes: d5dc0f43f268 ("drm/i915/gmbus: Enable burst read") Signed-off-by: Samasth Norway Ananda Reviewed-by: Jani Nikula Link: https://patch.msgid.link/20260316231920.135438-2-samasth.norway.ananda@oracle.com Signed-off-by: Jani Nikula (cherry picked from commit 4ab0f09ee73fc853d00466682635f67c531f909c) Signed-off-by: Joonas Lahtinen Signed-off-by: Sasha Levin

drm/i915/gt: Check set_default_submission() before deferencing

2026-03-25T10:10:45+00:00

[ Upstream commit 0162ab3220bac870e43e229e6e3024d1a21c3f26 ] When the i915 driver firmware binaries are not present, the set_default_submission pointer is not set. This pointer is dereferenced during suspend anyways. Add a check to make sure it is set before dereferencing. [ 23.289926] PM: suspend entry (deep) [ 23.293558] Filesystems sync: 0.000 seconds [ 23.298010] Freezing user space processes [ 23.302771] Freezing user space processes completed (elapsed 0.000 seconds) [ 23.309766] OOM killer disabled. [ 23.313027] Freezing remaining freezable tasks [ 23.318540] Freezing remaining freezable tasks completed (elapsed 0.001 seconds) [ 23.342038] serial 00:05: disabled [ 23.345719] serial 00:02: disabled [ 23.349342] serial 00:01: disabled [ 23.353782] sd 0:0:0:0: [sda] Synchronizing SCSI cache [ 23.358993] sd 1:0:0:0: [sdb] Synchronizing SCSI cache [ 23.361635] ata1.00: Entering standby power mode [ 23.368863] ata2.00: Entering standby power mode [ 23.445187] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 23.452194] #PF: supervisor instruction fetch in kernel mode [ 23.457896] #PF: error_code(0x0010) - not-present page [ 23.463065] PGD 0 P4D 0 [ 23.465640] Oops: Oops: 0010 [#1] SMP NOPTI [ 23.469869] CPU: 8 UID: 0 PID: 211 Comm: kworker/u48:18 Tainted: G S W 6.19.0-rc4-00020-gf0b9d8eb98df #10 PREEMPT(voluntary) [ 23.482512] Tainted: [S]=CPU_OUT_OF_SPEC, [W]=WARN [ 23.496511] Workqueue: async async_run_entry_fn [ 23.501087] RIP: 0010:0x0 [ 23.503755] Code: Unable to access opcode bytes at 0xffffffffffffffd6. [ 23.510324] RSP: 0018:ffffb4a60065fca8 EFLAGS: 00010246 [ 23.515592] RAX: 0000000000000000 RBX: ffff9f428290e000 RCX: 000000000000000f [ 23.522765] RDX: 0000000000000000 RSI: 0000000000000282 RDI: ffff9f428290e000 [ 23.529937] RBP: ffff9f4282907070 R08: ffff9f4281130428 R09: 00000000ffffffff [ 23.537111] R10: 0000000000000000 R11: 0000000000000001 R12: ffff9f42829070f8 [ 23.544284] R13: ffff9f4282906028 R14: ffff9f4282900000 R15: ffff9f4282906b68 [ 23.551457] FS: 0000000000000000(0000) GS:ffff9f466b2cf000(0000) knlGS:0000000000000000 [ 23.559588] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 23.565365] CR2: ffffffffffffffd6 CR3: 000000031c230001 CR4: 0000000000f70ef0 [ 23.572539] PKRU: 55555554 [ 23.575281] Call Trace: [ 23.577770] [ 23.579905] intel_engines_reset_default_submission+0x42/0x60 [ 23.585695] __intel_gt_unset_wedged+0x191/0x200 [ 23.590360] intel_gt_unset_wedged+0x20/0x40 [ 23.594675] gt_sanitize+0x15e/0x170 [ 23.598290] i915_gem_suspend_late+0x6b/0x180 [ 23.602692] i915_drm_suspend_late+0x35/0xf0 [ 23.607008] ? __pfx_pci_pm_suspend_late+0x10/0x10 [ 23.611843] dpm_run_callback+0x78/0x1c0 [ 23.615817] device_suspend_late+0xde/0x2e0 [ 23.620037] async_suspend_late+0x18/0x30 [ 23.624082] async_run_entry_fn+0x25/0xa0 [ 23.628129] process_one_work+0x15b/0x380 [ 23.632182] worker_thread+0x2a5/0x3c0 [ 23.635973] ? __pfx_worker_thread+0x10/0x10 [ 23.640279] kthread+0xf6/0x1f0 [ 23.643464] ? __pfx_kthread+0x10/0x10 [ 23.647263] ? __pfx_kthread+0x10/0x10 [ 23.651045] ret_from_fork+0x131/0x190 [ 23.654837] ? __pfx_kthread+0x10/0x10 [ 23.658634] ret_from_fork_asm+0x1a/0x30 [ 23.662597] [ 23.664826] Modules linked in: [ 23.667914] CR2: 0000000000000000 [ 23.671271] ------------[ cut here ]------------ Signed-off-by: Rahul Bukte Reviewed-by: Suraj Kandpal Signed-off-by: Suraj Kandpal Link: https://patch.msgid.link/20260203044839.1555147-1-suraj.kandpal@intel.com (cherry picked from commit daa199abc3d3d1740c9e3a2c3e9216ae5b447cad) Fixes: ff44ad51ebf8 ("drm/i915: Move engine->submit_request selection to a vfunc") Signed-off-by: Joonas Lahtinen Signed-off-by: Sasha Levin