From 033559473dd3b55558b535aa37b8848c207b5cbb Mon Sep 17 00:00:00 2001 From: Akash Goel Date: Tue, 21 Oct 2025 17:09:51 +0100 Subject: [PATCH 01/11] dma-fence: Fix safe access wrapper to call timeline name method This commit fixes the wrapper function dma_fence_timeline_name(), that was added for safe access, to actually call the timeline name method of dma_fence_ops. Cc: # v6.17+ Signed-off-by: Akash Goel Fixes: 506aa8b02a8d ("dma-fence: Add safe access helpers and document the rules") Reviewed-by: Tvrtko Ursulin Signed-off-by: Tvrtko Ursulin Link: https://lore.kernel.org/r/20251021160951.1415603-1-akash.goel@arm.com --- drivers/dma-buf/dma-fence.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index 3f78c56b58dc..39e6f93dc310 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c @@ -1141,7 +1141,7 @@ const char __rcu *dma_fence_timeline_name(struct dma_fence *fence) "RCU protection is required for safe access to returned string"); if (!test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) - return fence->ops->get_driver_name(fence); + return fence->ops->get_timeline_name(fence); else return "signaled-timeline"; } From 14e02ed3876f4ab0ed6d3f41972175f8b8df3d70 Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann Date: Fri, 17 Oct 2025 11:13:36 +0200 Subject: [PATCH 02/11] drm/sysfb: Do not dereference NULL pointer in plane reset The plane state in __drm_gem_reset_shadow_plane() can be NULL. Do not deref that pointer, but forward NULL to the other plane-reset helpers. Clears plane->state to NULL. v2: - fix typo in commit description (Javier) Signed-off-by: Thomas Zimmermann Fixes: b71565022031 ("drm/gem: Export implementation of shadow-plane helpers") Reported-by: Dan Carpenter Closes: https://lore.kernel.org/dri-devel/aPIDAsHIUHp_qSW4@stanley.mountain/ Cc: Thomas Zimmermann Cc: Melissa Wen Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: David Airlie Cc: Simona Vetter Cc: dri-devel@lists.freedesktop.org Cc: # v5.15+ Reviewed-by: Javier Martinez Canillas Link: https://patch.msgid.link/20251017091407.58488-1-tzimmermann@suse.de --- drivers/gpu/drm/drm_gem_atomic_helper.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_gem_atomic_helper.c b/drivers/gpu/drm/drm_gem_atomic_helper.c index ebf305fb24f0..6fb55601252f 100644 --- a/drivers/gpu/drm/drm_gem_atomic_helper.c +++ b/drivers/gpu/drm/drm_gem_atomic_helper.c @@ -310,8 +310,12 @@ EXPORT_SYMBOL(drm_gem_destroy_shadow_plane_state); void __drm_gem_reset_shadow_plane(struct drm_plane *plane, struct drm_shadow_plane_state *shadow_plane_state) { - __drm_atomic_helper_plane_reset(plane, &shadow_plane_state->base); - drm_format_conv_state_init(&shadow_plane_state->fmtcnv_state); + if (shadow_plane_state) { + __drm_atomic_helper_plane_reset(plane, &shadow_plane_state->base); + drm_format_conv_state_init(&shadow_plane_state->fmtcnv_state); + } else { + __drm_atomic_helper_plane_reset(plane, NULL); + } } EXPORT_SYMBOL(__drm_gem_reset_shadow_plane); From d25e3a610bae03bffc5c14b5d944a5d0cd844678 Mon Sep 17 00:00:00 2001 From: Philipp Stanner Date: Wed, 22 Oct 2025 08:34:03 +0200 Subject: [PATCH 03/11] drm/sched: Fix race in drm_sched_entity_select_rq() In a past bug fix it was forgotten that entity access must be protected by the entity lock. That's a data race and potentially UB. Move the spin_unlock() to the appropriate position. Cc: stable@vger.kernel.org # v5.13+ Fixes: ac4eb83ab255 ("drm/sched: select new rq even if there is only one v3") Reviewed-by: Tvrtko Ursulin Signed-off-by: Philipp Stanner Link: https://patch.msgid.link/20251022063402.87318-2-phasta@kernel.org --- drivers/gpu/drm/scheduler/sched_entity.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c index 5a4697f636f2..aa222166de58 100644 --- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -552,10 +552,11 @@ void drm_sched_entity_select_rq(struct drm_sched_entity *entity) drm_sched_rq_remove_entity(entity->rq, entity); entity->rq = rq; } - spin_unlock(&entity->lock); if (entity->num_sched_list == 1) entity->sched_list = NULL; + + spin_unlock(&entity->lock); } /** From e0023c8a74028739643aa14bd201c41a99866ca4 Mon Sep 17 00:00:00 2001 From: Philipp Stanner Date: Fri, 24 Oct 2025 18:12:22 +0200 Subject: [PATCH 04/11] drm/nouveau: Fix race in nouveau_sched_fini() nouveau_sched_fini() uses a memory barrier before wait_event(). wait_event(), however, is a macro which expands to a loop which might check the passed condition several times. The barrier would only take effect for the first check. Replace the barrier with a function which takes the spinlock. Cc: stable@vger.kernel.org # v6.8+ Fixes: 5f03a507b29e ("drm/nouveau: implement 1:1 scheduler - entity relationship") Acked-by: Danilo Krummrich Signed-off-by: Philipp Stanner Link: https://patch.msgid.link/20251024161221.196155-2-phasta@kernel.org --- drivers/gpu/drm/nouveau/nouveau_sched.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/nouveau/nouveau_sched.c b/drivers/gpu/drm/nouveau/nouveau_sched.c index e60f7892f5ce..a7bf539e5d86 100644 --- a/drivers/gpu/drm/nouveau/nouveau_sched.c +++ b/drivers/gpu/drm/nouveau/nouveau_sched.c @@ -482,6 +482,17 @@ nouveau_sched_create(struct nouveau_sched **psched, struct nouveau_drm *drm, return 0; } +static bool +nouveau_sched_job_list_empty(struct nouveau_sched *sched) +{ + bool empty; + + spin_lock(&sched->job.list.lock); + empty = list_empty(&sched->job.list.head); + spin_unlock(&sched->job.list.lock); + + return empty; +} static void nouveau_sched_fini(struct nouveau_sched *sched) @@ -489,8 +500,7 @@ nouveau_sched_fini(struct nouveau_sched *sched) struct drm_gpu_scheduler *drm_sched = &sched->base; struct drm_sched_entity *entity = &sched->entity; - rmb(); /* for list_empty to work without lock */ - wait_event(sched->job.wq, list_empty(&sched->job.list.head)); + wait_event(sched->job.wq, nouveau_sched_job_list_empty(sched)); drm_sched_entity_fini(entity); drm_sched_fini(drm_sched); From a042beac6e6f8ac1e923784cfff98b47cbabb185 Mon Sep 17 00:00:00 2001 From: Tomeu Vizoso Date: Tue, 21 Oct 2025 11:37:23 +0200 Subject: [PATCH 05/11] drm/etnaviv: fix flush sequence logic The current logic uses the flush sequence from the current address space. This is harmless when deducing the flush requirements for the current submit, as either the incoming address space is the same one as the currently active one or we switch context, in which case the flush is unconditional. However, this sequence is also stored as the current flush sequence of the GPU. If we switch context the stored flush sequence will no longer belong to the currently active address space. This incoherency can then cause missed flushes, resulting in translation errors. Fixes: 27b67278e007 ("drm/etnaviv: rework MMU handling") Signed-off-by: Tomeu Vizoso Signed-off-by: Lucas Stach Reviewed-by: Christian Gmeiner Link: https://lore.kernel.org/r/20251021093723.3887980-1-l.stach@pengutronix.de --- drivers/gpu/drm/etnaviv/etnaviv_buffer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/etnaviv/etnaviv_buffer.c b/drivers/gpu/drm/etnaviv/etnaviv_buffer.c index b13a17276d07..88385dc3b30d 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_buffer.c +++ b/drivers/gpu/drm/etnaviv/etnaviv_buffer.c @@ -347,7 +347,7 @@ void etnaviv_buffer_queue(struct etnaviv_gpu *gpu, u32 exec_state, u32 link_target, link_dwords; bool switch_context = gpu->exec_state != exec_state; bool switch_mmu_context = gpu->mmu_context != mmu_context; - unsigned int new_flush_seq = READ_ONCE(gpu->mmu_context->flush_seq); + unsigned int new_flush_seq = READ_ONCE(mmu_context->flush_seq); bool need_flush = switch_mmu_context || gpu->flush_seq != new_flush_seq; bool has_blt = !!(gpu->identity.minor_features5 & chipMinorFeatures5_BLT_ENGINE); From 9e8b3201c7302d5b522ba3535630bed21cc03c27 Mon Sep 17 00:00:00 2001 From: David Rosca Date: Wed, 15 Oct 2025 16:01:28 +0200 Subject: [PATCH 06/11] drm/sched: avoid killing parent entity on child SIGKILL MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The DRM scheduler tracks who last uses an entity and when that process is killed blocks all further submissions to that entity. The problem is that we didn't track who initially created an entity, so when a process accidently leaked its file descriptor to a child and that child got killed, we killed the parent's entities. Avoid that and instead initialize the entities last user on entity creation. This also allows to drop the extra NULL check. Signed-off-by: David Rosca Signed-off-by: Christian König Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4568 Reviewed-by: Alex Deucher CC: stable@vger.kernel.org Acked-by: Philipp Stanner Link: https://lore.kernel.org/r/20251015140128.1470-1-christian.koenig@amd.com Signed-off-by: Philipp Stanner Link: https://patch.msgid.link/20251015140128.1470-1-christian.koenig@amd.com --- drivers/gpu/drm/scheduler/sched_entity.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c index aa222166de58..c8e949f4a568 100644 --- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -70,6 +70,7 @@ int drm_sched_entity_init(struct drm_sched_entity *entity, entity->guilty = guilty; entity->num_sched_list = num_sched_list; entity->priority = priority; + entity->last_user = current->group_leader; /* * It's perfectly valid to initialize an entity without having a valid * scheduler attached. It's just not valid to use the scheduler before it @@ -302,7 +303,7 @@ long drm_sched_entity_flush(struct drm_sched_entity *entity, long timeout) /* For a killed process disallow further enqueueing of jobs. */ last_user = cmpxchg(&entity->last_user, current->group_leader, NULL); - if ((!last_user || last_user == current->group_leader) && + if (last_user == current->group_leader && (current->flags & PF_EXITING) && (current->exit_code == SIGKILL)) drm_sched_entity_kill(entity); From 056d76f7cb9fa68c8bbf85b4055aeb84af6139d5 Mon Sep 17 00:00:00 2001 From: Sebastian Reichel Date: Wed, 1 Oct 2025 01:59:42 +0200 Subject: [PATCH 07/11] drm/panel: sitronix-st7789v: fix sync flags for t28cp45tn89 I planned to set the polarity of horizontal and vertical sync, but accidentally described vertical sync twice with different polarity instead. Note, that there is no functional change, because the driver only makes use of DRM_MODE_FLAG_P[HV]SYNC to divert from the default active-low polarity. Reported-by: Laurent Pinchart Closes: https://lore.kernel.org/all/20250923132616.GH20765@pendragon.ideasonboard.com/ Fixes: a411558cc143 ("drm/panel: sitronix-st7789v: add Inanbo T28CP45TN89 support") Reviewed-by: Laurent Pinchart Reviewed-by: Marek Vasut Signed-off-by: Sebastian Reichel Signed-off-by: Neil Armstrong Link: https://lore.kernel.org/r/20251001-t28cp45tn89-fix-v2-1-67fe8e3046ca@collabora.com --- drivers/gpu/drm/panel/panel-sitronix-st7789v.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/panel/panel-sitronix-st7789v.c b/drivers/gpu/drm/panel/panel-sitronix-st7789v.c index 04d91929eedd..d5f821d6b23c 100644 --- a/drivers/gpu/drm/panel/panel-sitronix-st7789v.c +++ b/drivers/gpu/drm/panel/panel-sitronix-st7789v.c @@ -249,6 +249,11 @@ static const struct drm_display_mode default_mode = { .flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC, }; +/* + * The mode data for this panel has been reverse engineered without access + * to the panel datasheet / manual. Using DRM_MODE_FLAG_PHSYNC like all + * other panels results in garbage data on the display. + */ static const struct drm_display_mode t28cp45tn89_mode = { .clock = 6008, .hdisplay = 240, @@ -261,7 +266,7 @@ static const struct drm_display_mode t28cp45tn89_mode = { .vtotal = 320 + 8 + 4 + 4, .width_mm = 43, .height_mm = 57, - .flags = DRM_MODE_FLAG_PVSYNC | DRM_MODE_FLAG_NVSYNC, + .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_PVSYNC, }; static const struct drm_display_mode et028013dma_mode = { From d8eb00bbc628c8916ab0da2bb80059d48aa4512e Mon Sep 17 00:00:00 2001 From: Sebastian Fleer Date: Wed, 29 Oct 2025 13:35:28 +0100 Subject: [PATCH 08/11] drm/panel: kingdisplay-kd097d04: Disable EoTp Since commit d97e71e44937 ("drm/bridge: synopsys: dw-mipi-dsi: enable EoTp by default") panel output on an Acer Chromebook Tab 10 (google-dru) is corrupted. The tablet I use is equipped with a kingdisplay-kd097d04 panel, disabling EoTp restores the correct functionality. Fixes: 2a994cbed6b2 ("drm/panel: Add Kingdisplay KD097D04 panel driver") Suggested-by: Jens Reidel Signed-off-by: Sebastian Fleer Reviewed-by: Neil Armstrong Signed-off-by: Neil Armstrong Link: https://lore.kernel.org/r/20251029124007.232333-1-dev@dwurp.de --- drivers/gpu/drm/panel/panel-kingdisplay-kd097d04.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/panel/panel-kingdisplay-kd097d04.c b/drivers/gpu/drm/panel/panel-kingdisplay-kd097d04.c index 2fc7b0779b37..893af9b16756 100644 --- a/drivers/gpu/drm/panel/panel-kingdisplay-kd097d04.c +++ b/drivers/gpu/drm/panel/panel-kingdisplay-kd097d04.c @@ -359,7 +359,7 @@ static int kingdisplay_panel_probe(struct mipi_dsi_device *dsi) dsi->lanes = 4; dsi->format = MIPI_DSI_FMT_RGB888; dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST | - MIPI_DSI_MODE_LPM; + MIPI_DSI_MODE_LPM | MIPI_DSI_MODE_NO_EOT_PACKET; kingdisplay = devm_drm_panel_alloc(&dsi->dev, __typeof(*kingdisplay), base, &kingdisplay_panel_funcs, From 3257bd193fa1702791978d8418c9a96e3def082c Mon Sep 17 00:00:00 2001 From: Luca Ceresoli Date: Tue, 14 Oct 2025 13:30:51 +0200 Subject: [PATCH 09/11] drm/imx: parallel-display: convert to devm_drm_bridge_alloc() API This is the new API for allocating DRM bridges. This conversion was missed during the initial conversion of all bridges to the new API. Thus all kernels with commit 94d50c1a2ca3 ("drm/bridge: get/put the bridge reference in drm_bridge_attach/detach()") and using this driver now warn due to drm_bridge_attach() incrementing the refcount, which is not initialized without using devm_drm_bridge_alloc() for allocation. To make the conversion simple and straightforward without messing up with the drmm_simple_encoder_alloc(), move the struct drm_bridge from struct imx_parallel_display_encoder to struct imx_parallel_display. Also remove the 'struct imx_parallel_display *pd' from struct imx_parallel_display_encoder, not needed anymore. Fixes: 94d50c1a2ca3 ("drm/bridge: get/put the bridge reference in drm_bridge_attach/detach()") Reported-by: Ernest Van Hoecke Closes: https://lore.kernel.org/all/hlf4wdopapxnh4rekl5s3kvoi6egaga3lrjfbx6r223ar3txri@3ik53xw5idyh/ Signed-off-by: Luca Ceresoli Reviewed-by: Louis Chauvet Tested-by: Ernest Van Hoecke Link: https://patch.msgid.link/20251014-drm-bridge-alloc-imx-ipuv3-v1-1-a1bb1dcbff50@bootlin.com Signed-off-by: Philipp Zabel --- drivers/gpu/drm/imx/ipuv3/parallel-display.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/imx/ipuv3/parallel-display.c b/drivers/gpu/drm/imx/ipuv3/parallel-display.c index 6d8325c76697..3d0de9c6e925 100644 --- a/drivers/gpu/drm/imx/ipuv3/parallel-display.c +++ b/drivers/gpu/drm/imx/ipuv3/parallel-display.c @@ -25,19 +25,18 @@ struct imx_parallel_display_encoder { struct drm_encoder encoder; - struct drm_bridge bridge; - struct imx_parallel_display *pd; }; struct imx_parallel_display { struct device *dev; u32 bus_format; struct drm_bridge *next_bridge; + struct drm_bridge bridge; }; static inline struct imx_parallel_display *bridge_to_imxpd(struct drm_bridge *b) { - return container_of(b, struct imx_parallel_display_encoder, bridge)->pd; + return container_of(b, struct imx_parallel_display, bridge); } static const u32 imx_pd_bus_fmts[] = { @@ -195,15 +194,13 @@ static int imx_pd_bind(struct device *dev, struct device *master, void *data) if (IS_ERR(imxpd_encoder)) return PTR_ERR(imxpd_encoder); - imxpd_encoder->pd = imxpd; encoder = &imxpd_encoder->encoder; - bridge = &imxpd_encoder->bridge; + bridge = &imxpd->bridge; ret = imx_drm_encoder_parse_of(drm, encoder, imxpd->dev->of_node); if (ret) return ret; - bridge->funcs = &imx_pd_bridge_funcs; drm_bridge_attach(encoder, bridge, NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR); connector = drm_bridge_connector_init(drm, encoder); @@ -228,9 +225,10 @@ static int imx_pd_probe(struct platform_device *pdev) u32 bus_format = 0; const char *fmt; - imxpd = devm_kzalloc(dev, sizeof(*imxpd), GFP_KERNEL); - if (!imxpd) - return -ENOMEM; + imxpd = devm_drm_bridge_alloc(dev, struct imx_parallel_display, bridge, + &imx_pd_bridge_funcs); + if (IS_ERR(imxpd)) + return PTR_ERR(imxpd); /* port@1 is the output port */ imxpd->next_bridge = devm_drm_of_get_bridge(dev, np, 1, 0); From bf7e97910b9f4d9679e075a39be371a4ed65dbd4 Mon Sep 17 00:00:00 2001 From: Luca Ceresoli Date: Tue, 14 Oct 2025 13:30:52 +0200 Subject: [PATCH 10/11] drm/imx: parallel-display: add the bridge before attaching it Invoking drm_bridge_add() is good practice, so add it to this driver. Link: https://lore.kernel.org/all/DDHZ5GO9MPF0.CGYTVBI74FOZ@bootlin.com Signed-off-by: Luca Ceresoli Reviewed-by: Louis Chauvet Link: https://patch.msgid.link/20251014-drm-bridge-alloc-imx-ipuv3-v1-2-a1bb1dcbff50@bootlin.com Signed-off-by: Philipp Zabel --- drivers/gpu/drm/imx/ipuv3/parallel-display.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/imx/ipuv3/parallel-display.c b/drivers/gpu/drm/imx/ipuv3/parallel-display.c index 3d0de9c6e925..7fc6af703307 100644 --- a/drivers/gpu/drm/imx/ipuv3/parallel-display.c +++ b/drivers/gpu/drm/imx/ipuv3/parallel-display.c @@ -256,6 +256,8 @@ static int imx_pd_probe(struct platform_device *pdev) platform_set_drvdata(pdev, imxpd); + devm_drm_bridge_add(dev, &imxpd->bridge); + return component_add(dev, &imx_pd_ops); } From a9fb41b5def8e1e0103d5fd1453787993587281e Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann Date: Fri, 24 Oct 2025 09:35:53 +0200 Subject: [PATCH 11/11] drm/ast: Clear preserved bits from register output value Preserve the I/O register bits in __ast_write8_i_masked() as specified by preserve_mask. Accidentally OR-ing the output value into these will overwrite the register's previous settings. Fixes display output on the AST2300, where the screen can go blank at boot. The driver's original commit 312fec1405dd ("drm: Initial KMS driver for AST (ASpeed Technologies) 2000 series (v2)") already added the broken code. Commit 6f719373b943 ("drm/ast: Blank with VGACR17 sync enable, always clear VGACRB6 sync off") triggered the bug. Signed-off-by: Thomas Zimmermann Reported-by: Peter Schneider Closes: https://lore.kernel.org/dri-devel/a40caf8e-58ad-4f9c-af7f-54f6f69c29bb@googlemail.com/ Tested-by: Peter Schneider Reviewed-by: Jocelyn Falempe Fixes: 6f719373b943 ("drm/ast: Blank with VGACR17 sync enable, always clear VGACRB6 sync off") Fixes: 312fec1405dd ("drm: Initial KMS driver for AST (ASpeed Technologies) 2000 series (v2)") Cc: Thomas Zimmermann Cc: Nick Bowler Cc: Douglas Anderson Cc: Dave Airlie Cc: Jocelyn Falempe Cc: dri-devel@lists.freedesktop.org Cc: # v3.5+ Link: https://patch.msgid.link/20251024073626.129032-1-tzimmermann@suse.de --- drivers/gpu/drm/ast/ast_drv.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/ast/ast_drv.h b/drivers/gpu/drm/ast/ast_drv.h index c15aef014f69..d41bd876167c 100644 --- a/drivers/gpu/drm/ast/ast_drv.h +++ b/drivers/gpu/drm/ast/ast_drv.h @@ -282,13 +282,13 @@ static inline void __ast_write8_i(void __iomem *addr, u32 reg, u8 index, u8 val) __ast_write8(addr, reg + 1, val); } -static inline void __ast_write8_i_masked(void __iomem *addr, u32 reg, u8 index, u8 read_mask, +static inline void __ast_write8_i_masked(void __iomem *addr, u32 reg, u8 index, u8 preserve_mask, u8 val) { - u8 tmp = __ast_read8_i_masked(addr, reg, index, read_mask); + u8 tmp = __ast_read8_i_masked(addr, reg, index, preserve_mask); - tmp |= val; - __ast_write8_i(addr, reg, index, tmp); + val &= ~preserve_mask; + __ast_write8_i(addr, reg, index, tmp | val); } static inline u32 ast_read32(struct ast_device *ast, u32 reg)