Merge tag 'drm-misc-fixes-2026-04-02' of https://gitlab.freedesktop.org/drm/misc/kernel into drm-fixes

A refcounting fix for bridges, revert a previous framebuffer
use-after-free fix that turned out to be causing more problems, a hang
fix for qaic, an initialization fix for ast, a error handling fix for
sysfb, and a speculation fix for drm_compat_ioctl.

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Maxime Ripard <mripard@redhat.com>
Link: https://patch.msgid.link/20260402-vivid-perfect-caiman-ca055e@houat

Author: airlied

drivers/accel/qaic/qaic_control.c

@@ -914,7 +914,7 @@ static int decode_deactivate(struct qaic_device *qdev, void *trans, u32 *msg_len
 		 */
 		return -ENODEV;
 
-	if (status) {
+	if (usr && status) {
 		/*
 		 * Releasing resources failed on the device side, which puts
 		 * us in a bind since they may still be in use, so enable the
@@ -1109,6 +1109,9 @@ static void *msg_xfer(struct qaic_device *qdev, struct wrapper_list *wrappers, u
 	mutex_lock(&qdev->cntl_mutex);
 	if (!list_empty(&elem.list))
 		list_del(&elem.list);
+	/* resp_worker() processed the response but the wait was interrupted */
+	else if (ret == -ERESTARTSYS)
+		ret = 0;
 	if (!ret && !elem.buf)
 		ret = -ETIMEDOUT;
 	else if (ret > 0 && !elem.buf)
@@ -1419,9 +1422,49 @@ static void resp_worker(struct work_struct *work)
 	}
 	mutex_unlock(&qdev->cntl_mutex);
 
-	if (!found)
+	if (!found) {
+		/*
+		 * The user might have gone away at this point without waiting
+		 * for QAIC_TRANS_DEACTIVATE_FROM_DEV transaction coming from
+		 * the device. If this is not handled correctly, the host will
+		 * not know that the DBC[n] has been freed on the device.
+		 * Due to this failure in synchronization between the device and
+		 * the host, if another user requests to activate a network, and
+		 * the device assigns DBC[n] again, save_dbc_buf() will hang,
+		 * waiting for dbc[n]->in_use to be set to false, which will not
+		 * happen unless the qaic_dev_reset_clean_local_state() gets
+		 * called by resetting the device (or re-inserting the module).
+		 *
+		 * As a solution, we look for QAIC_TRANS_DEACTIVATE_FROM_DEV
+		 * transactions in the message before disposing of it, then
+		 * handle releasing the DBC resources.
+		 *
+		 * Since the user has gone away, if the device could not
+		 * deactivate the network (status != 0), there is no way to
+		 * enable and reassign the DBC to the user. We can put trust in
+		 * the device that it will release all the active DBCs in
+		 * response to the QAIC_TRANS_TERMINATE_TO_DEV transaction,
+		 * otherwise, the user can issue an soc_reset to the device.
+		 */
+		u32 msg_count = le32_to_cpu(msg->hdr.count);
+		u32 msg_len = le32_to_cpu(msg->hdr.len);
+		u32 len = 0;
+		int j;
+
+		for (j = 0; j < msg_count && len < msg_len; ++j) {
+			struct wire_trans_hdr *trans_hdr;
+
+			trans_hdr = (struct wire_trans_hdr *)(msg->data + len);
+			if (le32_to_cpu(trans_hdr->type) == QAIC_TRANS_DEACTIVATE_FROM_DEV) {
+				if (decode_deactivate(qdev, trans_hdr, &len, NULL))
+					len += le32_to_cpu(trans_hdr->len);
+			} else {
+				len += le32_to_cpu(trans_hdr->len);
+			}
+		}
 		/* request must have timed out, drop packet */
 		kfree(msg);
+	}
 
 	kfree(resp);
 }

drivers/gpu/drm/ast/ast_dp501.c

@@ -436,7 +436,7 @@ static void ast_init_analog(struct ast_device *ast)
 	/* Finally, clear bits [17:16] of SCU2c */
 	data = ast_read32(ast, 0x1202c);
 	data &= 0xfffcffff;
-	ast_write32(ast, 0, data);
+	ast_write32(ast, 0x1202c, data);
 
 	/* Disable DVO */
 	ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xa3, 0xcf, 0x00);

drivers/gpu/drm/drm_bridge.c

@@ -1569,11 +1569,17 @@ EXPORT_SYMBOL(devm_drm_put_bridge);
 static void drm_bridge_debugfs_show_bridge(struct drm_printer *p,
 					   struct drm_bridge *bridge,
 					   unsigned int idx,
-					   bool lingering)
+					   bool lingering,
+					   bool scoped)
 {
+	unsigned int refcount = kref_read(&bridge->refcount);
+
+	if (scoped)
+		refcount--;
+
 	drm_printf(p, "bridge[%u]: %ps\n", idx, bridge->funcs);
 
-	drm_printf(p, "\trefcount: %u%s\n", kref_read(&bridge->refcount),
+	drm_printf(p, "\trefcount: %u%s\n", refcount,
 		   lingering ? " [lingering]" : "");
 
 	drm_printf(p, "\ttype: [%d] %s\n",
@@ -1607,10 +1613,10 @@ static int allbridges_show(struct seq_file *m, void *data)
 	mutex_lock(&bridge_lock);
 
 	list_for_each_entry(bridge, &bridge_list, list)
-		drm_bridge_debugfs_show_bridge(&p, bridge, idx++, false);
+		drm_bridge_debugfs_show_bridge(&p, bridge, idx++, false, false);
 
 	list_for_each_entry(bridge, &bridge_lingering_list, list)
-		drm_bridge_debugfs_show_bridge(&p, bridge, idx++, true);
+		drm_bridge_debugfs_show_bridge(&p, bridge, idx++, true, false);
 
 	mutex_unlock(&bridge_lock);
 
@@ -1625,7 +1631,7 @@ static int encoder_bridges_show(struct seq_file *m, void *data)
 	unsigned int idx = 0;
 
 	drm_for_each_bridge_in_chain_scoped(encoder, bridge)
-		drm_bridge_debugfs_show_bridge(&p, bridge, idx++, false);
+		drm_bridge_debugfs_show_bridge(&p, bridge, idx++, false, true);
 
 	return 0;
 }

drivers/gpu/drm/drm_file.c

@@ -233,7 +233,6 @@ static void drm_events_release(struct drm_file *file_priv)
 void drm_file_free(struct drm_file *file)
 {
 	struct drm_device *dev;
-	int idx;
 
 	if (!file)
 		return;
@@ -250,11 +249,9 @@ void drm_file_free(struct drm_file *file)
 
 	drm_events_release(file);
 
-	if (drm_core_check_feature(dev, DRIVER_MODESET) &&
-	    drm_dev_enter(dev, &idx)) {
+	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
 		drm_fb_release(file);
 		drm_property_destroy_user_blobs(dev, file);
-		drm_dev_exit(idx);
 	}
 
 	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))

drivers/gpu/drm/drm_ioc32.c

@@ -28,6 +28,7 @@
  * IN THE SOFTWARE.
  */
 #include <linux/compat.h>
+#include <linux/nospec.h>
 #include <linux/ratelimit.h>
 #include <linux/export.h>
 
@@ -374,6 +375,7 @@ long drm_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 	if (nr >= ARRAY_SIZE(drm_compat_ioctls))
 		return drm_ioctl(filp, cmd, arg);
 
+	nr = array_index_nospec(nr, ARRAY_SIZE(drm_compat_ioctls));
 	fn = drm_compat_ioctls[nr].fn;
 	if (!fn)
 		return drm_ioctl(filp, cmd, arg);

drivers/gpu/drm/drm_mode_config.c

@@ -577,13 +577,10 @@ void drm_mode_config_cleanup(struct drm_device *dev)
 	 */
 	WARN_ON(!list_empty(&dev->mode_config.fb_list));
 	list_for_each_entry_safe(fb, fbt, &dev->mode_config.fb_list, head) {
-		if (list_empty(&fb->filp_head) || drm_framebuffer_read_refcount(fb) > 1) {
-			struct drm_printer p = drm_dbg_printer(dev, DRM_UT_KMS, "[leaked fb]");
+		struct drm_printer p = drm_dbg_printer(dev, DRM_UT_KMS, "[leaked fb]");
 
-			drm_printf(&p, "framebuffer[%u]:\n", fb->base.id);
-			drm_framebuffer_print_info(&p, 1, fb);
-		}
-		list_del_init(&fb->filp_head);
+		drm_printf(&p, "framebuffer[%u]:\n", fb->base.id);
+		drm_framebuffer_print_info(&p, 1, fb);
 		drm_framebuffer_free(&fb->base.refcount);
 	}
 

drivers/gpu/drm/sysfb/efidrm.c

@@ -151,7 +151,6 @@ static struct efidrm_device *efidrm_device_create(struct drm_driver *drv,
 	struct drm_sysfb_device *sysfb;
 	struct drm_device *dev;
 	struct resource *mem = NULL;
-	void __iomem *screen_base = NULL;
 	struct drm_plane *primary_plane;
 	struct drm_crtc *crtc;
 	struct drm_encoder *encoder;
@@ -238,21 +237,38 @@ static struct efidrm_device *efidrm_device_create(struct drm_driver *drv,
 
 	mem_flags = efidrm_get_mem_flags(dev, res->start, vsize);
 
-	if (mem_flags & EFI_MEMORY_WC)
-		screen_base = devm_ioremap_wc(&pdev->dev, mem->start, resource_size(mem));
-	else if (mem_flags & EFI_MEMORY_UC)
-		screen_base = devm_ioremap(&pdev->dev, mem->start, resource_size(mem));
-	else if (mem_flags & EFI_MEMORY_WT)
-		screen_base = devm_memremap(&pdev->dev, mem->start, resource_size(mem),
-					    MEMREMAP_WT);
-	else if (mem_flags & EFI_MEMORY_WB)
-		screen_base = devm_memremap(&pdev->dev, mem->start, resource_size(mem),
-					    MEMREMAP_WB);
-	else
+	if (mem_flags & EFI_MEMORY_WC) {
+		void __iomem *screen_base = devm_ioremap_wc(&pdev->dev, mem->start,
+							    resource_size(mem));
+
+		if (!screen_base)
+			return ERR_PTR(-ENXIO);
+		iosys_map_set_vaddr_iomem(&sysfb->fb_addr, screen_base);
+	} else if (mem_flags & EFI_MEMORY_UC) {
+		void __iomem *screen_base = devm_ioremap(&pdev->dev, mem->start,
+							 resource_size(mem));
+
+		if (!screen_base)
+			return ERR_PTR(-ENXIO);
+		iosys_map_set_vaddr_iomem(&sysfb->fb_addr, screen_base);
+	} else if (mem_flags & EFI_MEMORY_WT) {
+		void *screen_base = devm_memremap(&pdev->dev, mem->start,
+						  resource_size(mem), MEMREMAP_WT);
+
+		if (IS_ERR(screen_base))
+			return ERR_CAST(screen_base);
+		iosys_map_set_vaddr(&sysfb->fb_addr, screen_base);
+	} else if (mem_flags & EFI_MEMORY_WB) {
+		void *screen_base = devm_memremap(&pdev->dev, mem->start,
+						  resource_size(mem), MEMREMAP_WB);
+
+		if (IS_ERR(screen_base))
+			return ERR_CAST(screen_base);
+		iosys_map_set_vaddr(&sysfb->fb_addr, screen_base);
+	} else {
 		drm_err(dev, "invalid mem_flags: 0x%llx\n", mem_flags);
-	if (!screen_base)
-		return ERR_PTR(-ENOMEM);
-	iosys_map_set_vaddr_iomem(&sysfb->fb_addr, screen_base);
+		return ERR_PTR(-EINVAL);
+	}
 
 	/*
 	 * Modesetting