Merge tag 'drm-misc-next-2018-09-19' of git://anongit.freedesktop.org/drm/drm-misc into drm-next

drm-misc-next for 4.20:

UAPI Changes:
- None

Cross-subsystem Changes:
- None

Core Changes:
- Allow drivers to disable features with per-device granularity (Ville)
- Use EOPNOTSUPP when iface/feature is unsupported instead of
  EINVAL/errno soup (Chris)
- Simplify M/N DP quirk by using constant N to limit size of M/N (Shawn)
- add quirk for LG LP140WF6-SPM1 eDP panel (Shawn)

Driver Changes:
- i915/amdgpu: Disable DRIVER_ATOMIC for older/unsupported devices (Ville)
- sun4i: add support for R40 HDMI PHY (Icenowy)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Icenowy Zheng <icenowy@aosc.io>
Cc: Lee, Shawn C <shawn.c.lee@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Sean Paul <sean@poorly.run>
Link: https://patchwork.freedesktop.org/patch/msgid/20180919200218.GA186644@art_vandelay

Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt

@@ -107,6 +107,7 @@ Required properties:
   - compatible: value must be one of:
     * allwinner,sun8i-a83t-hdmi-phy
     * allwinner,sun8i-h3-hdmi-phy
+    * allwinner,sun8i-r40-hdmi-phy
     * allwinner,sun50i-a64-hdmi-phy
   - reg: base address and size of memory-mapped region
   - clocks: phandles to the clocks feeding the HDMI PHY
@@ -116,9 +117,9 @@ Required properties:
   - resets: phandle to the reset controller driving the PHY
   - reset-names: must be "phy"
 
-H3 and A64 HDMI PHY require additional clocks:
+H3, A64 and R40 HDMI PHY require additional clocks:
   - pll-0: parent of phy clock
-  - pll-1: second possible phy clock parent (A64 only)
+  - pll-1: second possible phy clock parent (A64/R40 only)
 
 TV Encoder
 ----------

drivers/dma-buf/udmabuf.c

@@ -61,8 +61,10 @@ static struct sg_table *map_udmabuf(struct dma_buf_attachment *at,
 					GFP_KERNEL);
 	if (ret < 0)
 		goto err;
-	if (!dma_map_sg(at->dev, sg->sgl, sg->nents, direction))
+	if (!dma_map_sg(at->dev, sg->sgl, sg->nents, direction)) {
+		ret = -EINVAL;
 		goto err;
+	}
 	return sg;
 
 err:

drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c

@@ -816,17 +816,13 @@ static int amdgpu_pci_probe(struct pci_dev *pdev,
 	if (ret)
 		return ret;
 
-	/* warn the user if they mix atomic and non-atomic capable GPUs */
-	if ((kms_driver.driver_features & DRIVER_ATOMIC) && !supports_atomic)
-		DRM_ERROR("Mixing atomic and non-atomic capable GPUs!\n");
-	/* support atomic early so the atomic debugfs stuff gets created */
-	if (supports_atomic)
-		kms_driver.driver_features |= DRIVER_ATOMIC;
-
 	dev = drm_dev_alloc(&kms_driver, &pdev->dev);
 	if (IS_ERR(dev))
 		return PTR_ERR(dev);
 
+	if (!supports_atomic)
+		dev->driver_features &= ~DRIVER_ATOMIC;
+
 	ret = pci_enable_device(pdev);
 	if (ret)
 		goto err_free;
@@ -1078,7 +1074,7 @@ amdgpu_get_crtc_scanout_position(struct drm_device *dev, unsigned int pipe,
 
 static struct drm_driver kms_driver = {
 	.driver_features =
-	    DRIVER_USE_AGP |
+	    DRIVER_USE_AGP | DRIVER_ATOMIC |
 	    DRIVER_HAVE_IRQ | DRIVER_IRQ_SHARED | DRIVER_GEM |
 	    DRIVER_PRIME | DRIVER_RENDER | DRIVER_MODESET | DRIVER_SYNCOBJ,
 	.load = amdgpu_driver_load_kms,

drivers/gpu/drm/drm_atomic_uapi.c

@@ -1251,7 +1251,7 @@ int drm_mode_atomic_ioctl(struct drm_device *dev,
 
 	/* disallow for drivers not supporting atomic: */
 	if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	/* disallow for userspace that has not enabled atomic cap (even
 	 * though this may be a bit overkill, since legacy userspace

drivers/gpu/drm/drm_bufs.c

@@ -398,7 +398,7 @@ int drm_legacy_addmap_ioctl(struct drm_device *dev, void *data,
 
 	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	err = drm_addmap_core(dev, map->offset, map->size, map->type,
 			      map->flags, &maplist);
@@ -444,7 +444,7 @@ int drm_legacy_getmap_ioctl(struct drm_device *dev, void *data,
 
 	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	idx = map->offset;
 	if (idx < 0)
@@ -596,7 +596,7 @@ int drm_legacy_rmmap_ioctl(struct drm_device *dev, void *data,
 
 	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	mutex_lock(&dev->struct_mutex);
 	list_for_each_entry(r_list, &dev->maplist, head) {
@@ -860,7 +860,7 @@ int drm_legacy_addbufs_pci(struct drm_device *dev,
 	struct drm_buf **temp_buflist;
 
 	if (!drm_core_check_feature(dev, DRIVER_PCI_DMA))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!dma)
 		return -EINVAL;
@@ -1064,7 +1064,7 @@ static int drm_legacy_addbufs_sg(struct drm_device *dev,
 	struct drm_buf **temp_buflist;
 
 	if (!drm_core_check_feature(dev, DRIVER_SG))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!dma)
 		return -EINVAL;
@@ -1221,10 +1221,10 @@ int drm_legacy_addbufs(struct drm_device *dev, void *data,
 	int ret;
 
 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 #if IS_ENABLED(CONFIG_AGP)
 	if (request->flags & _DRM_AGP_BUFFER)
@@ -1267,10 +1267,10 @@ int __drm_legacy_infobufs(struct drm_device *dev,
 	int count;
 
 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!dma)
 		return -EINVAL;
@@ -1352,10 +1352,10 @@ int drm_legacy_markbufs(struct drm_device *dev, void *data,
 	struct drm_buf_entry *entry;
 
 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!dma)
 		return -EINVAL;
@@ -1400,10 +1400,10 @@ int drm_legacy_freebufs(struct drm_device *dev, void *data,
 	struct drm_buf *buf;
 
 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!dma)
 		return -EINVAL;
@@ -1455,10 +1455,10 @@ int __drm_legacy_mapbufs(struct drm_device *dev, void *data, int *p,
 	int i;
 
 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!dma)
 		return -EINVAL;
@@ -1545,7 +1545,7 @@ int drm_legacy_dma_ioctl(struct drm_device *dev, void *data,
 		  struct drm_file *file_priv)
 {
 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (dev->driver->dma_ioctl)
 		return dev->driver->dma_ioctl(dev, data, file_priv);

drivers/gpu/drm/drm_client.c

@@ -82,7 +82,7 @@ int drm_client_new(struct drm_device *dev, struct drm_client_dev *client,
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET) ||
 	    !dev->driver->dumb_create || !dev->driver->gem_prime_vmap)
-		return -ENOTSUPP;
+		return -EOPNOTSUPP;
 
 	if (funcs && !try_module_get(funcs->owner))
 		return -ENODEV;

drivers/gpu/drm/drm_color_mgmt.c

@@ -242,7 +242,7 @@ int drm_mode_gamma_set_ioctl(struct drm_device *dev,
 	int ret = 0;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	crtc = drm_crtc_find(dev, file_priv, crtc_lut->crtc_id);
 	if (!crtc)
@@ -320,7 +320,7 @@ int drm_mode_gamma_get_ioctl(struct drm_device *dev,
 	int ret = 0;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	crtc = drm_crtc_find(dev, file_priv, crtc_lut->crtc_id);
 	if (!crtc)

drivers/gpu/drm/drm_connector.c

@@ -1725,7 +1725,7 @@ int drm_mode_getconnector(struct drm_device *dev, void *data,
 	LIST_HEAD(export_list);
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	memset(&u_mode, 0, sizeof(struct drm_mode_modeinfo));
 

drivers/gpu/drm/drm_context.c

@@ -178,7 +178,7 @@ int drm_legacy_getsareactx(struct drm_device *dev, void *data,
 
 	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	mutex_lock(&dev->struct_mutex);
 
@@ -226,7 +226,7 @@ int drm_legacy_setsareactx(struct drm_device *dev, void *data,
 
 	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	mutex_lock(&dev->struct_mutex);
 	list_for_each_entry(r_list, &dev->maplist, head) {
@@ -330,7 +330,7 @@ int drm_legacy_resctx(struct drm_device *dev, void *data,
 
 	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (res->count >= DRM_RESERVED_CONTEXTS) {
 		memset(&ctx, 0, sizeof(ctx));
@@ -364,7 +364,7 @@ int drm_legacy_addctx(struct drm_device *dev, void *data,
 
 	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	ctx->handle = drm_legacy_ctxbitmap_next(dev);
 	if (ctx->handle == DRM_KERNEL_CONTEXT) {
@@ -411,7 +411,7 @@ int drm_legacy_getctx(struct drm_device *dev, void *data,
 
 	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	/* This is 0, because we don't handle any context flags */
 	ctx->flags = 0;
@@ -437,7 +437,7 @@ int drm_legacy_switchctx(struct drm_device *dev, void *data,
 
 	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	DRM_DEBUG("%d\n", ctx->handle);
 	return drm_context_switch(dev, dev->last_context, ctx->handle);
@@ -461,7 +461,7 @@ int drm_legacy_newctx(struct drm_device *dev, void *data,
 
 	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	DRM_DEBUG("%d\n", ctx->handle);
 	drm_context_switch_complete(dev, file_priv, ctx->handle);
@@ -487,7 +487,7 @@ int drm_legacy_rmctx(struct drm_device *dev, void *data,
 
 	if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 	    !drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	DRM_DEBUG("%d\n", ctx->handle);
 	if (ctx->handle != DRM_KERNEL_CONTEXT) {

drivers/gpu/drm/drm_crtc.c

@@ -405,7 +405,7 @@ int drm_mode_getcrtc(struct drm_device *dev,
 	struct drm_plane *plane;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	crtc = drm_crtc_find(dev, file_priv, crtc_resp->crtc_id);
 	if (!crtc)
@@ -580,7 +580,7 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
 	int i;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	/*
 	 * Universal plane src offsets are only 16.16, prevent havoc for

drivers/gpu/drm/drm_dp_helper.c

@@ -1257,15 +1257,22 @@ EXPORT_SYMBOL(drm_dp_stop_crc);
 
 struct dpcd_quirk {
 	u8 oui[3];
+	u8 device_id[6];
 	bool is_branch;
 	u32 quirks;
 };
 
 #define OUI(first, second, third) { (first), (second), (third) }
+#define DEVICE_ID(first, second, third, fourth, fifth, sixth) \
+	{ (first), (second), (third), (fourth), (fifth), (sixth) }
+
+#define DEVICE_ID_ANY	DEVICE_ID(0, 0, 0, 0, 0, 0)
 
 static const struct dpcd_quirk dpcd_quirk_list[] = {
 	/* Analogix 7737 needs reduced M and N at HBR2 link rates */
-	{ OUI(0x00, 0x22, 0xb9), true, BIT(DP_DPCD_QUIRK_LIMITED_M_N) },
+	{ OUI(0x00, 0x22, 0xb9), DEVICE_ID_ANY, true, BIT(DP_DPCD_QUIRK_CONSTANT_N) },
+	/* LG LP140WF6-SPM1 eDP panel */
+	{ OUI(0x00, 0x22, 0xb9), DEVICE_ID('s', 'i', 'v', 'a', 'r', 'T'), false, BIT(DP_DPCD_QUIRK_CONSTANT_N) },
 };
 
 #undef OUI
@@ -1284,6 +1291,7 @@ drm_dp_get_quirks(const struct drm_dp_dpcd_ident *ident, bool is_branch)
 	const struct dpcd_quirk *quirk;
 	u32 quirks = 0;
 	int i;
+	u8 any_device[] = DEVICE_ID_ANY;
 
 	for (i = 0; i < ARRAY_SIZE(dpcd_quirk_list); i++) {
 		quirk = &dpcd_quirk_list[i];
@@ -1294,12 +1302,19 @@ drm_dp_get_quirks(const struct drm_dp_dpcd_ident *ident, bool is_branch)
 		if (memcmp(quirk->oui, ident->oui, sizeof(ident->oui)) != 0)
 			continue;
 
+		if (memcmp(quirk->device_id, any_device, sizeof(any_device)) != 0 &&
+		    memcmp(quirk->device_id, ident->device_id, sizeof(ident->device_id)) != 0)
+			continue;
+
 		quirks |= quirk->quirks;
 	}
 
 	return quirks;
 }
 
+#undef DEVICE_ID_ANY
+#undef DEVICE_ID
+
 /**
  * drm_dp_read_desc - read sink/branch descriptor from DPCD
  * @aux: DisplayPort AUX channel

drivers/gpu/drm/drm_drv.c

@@ -506,6 +506,9 @@ int drm_dev_init(struct drm_device *dev,
 	dev->dev = parent;
 	dev->driver = driver;
 
+	/* no per-device feature limits by default */
+	dev->driver_features = ~0u;
+
 	INIT_LIST_HEAD(&dev->filelist);
 	INIT_LIST_HEAD(&dev->filelist_internal);
 	INIT_LIST_HEAD(&dev->clientlist);

drivers/gpu/drm/drm_encoder.c

@@ -222,7 +222,7 @@ int drm_mode_getencoder(struct drm_device *dev, void *data,
 	struct drm_crtc *crtc;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	encoder = drm_encoder_find(dev, file_priv, enc_resp->encoder_id);
 	if (!encoder)

drivers/gpu/drm/drm_framebuffer.c

@@ -113,6 +113,9 @@ int drm_mode_addfb(struct drm_device *dev, struct drm_mode_fb_cmd *or,
 	struct drm_mode_fb_cmd2 r = {};
 	int ret;
 
+	if (!drm_core_check_feature(dev, DRIVER_MODESET))
+		return -EOPNOTSUPP;
+
 	r.pixel_format = drm_mode_legacy_fb_format(or->bpp, or->depth);
 	if (r.pixel_format == DRM_FORMAT_INVALID) {
 		DRM_DEBUG("bad {bpp:%d, depth:%d}\n", or->bpp, or->depth);
@@ -352,7 +355,7 @@ int drm_mode_addfb2(struct drm_device *dev,
 	struct drm_framebuffer *fb;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	fb = drm_internal_framebuffer_create(dev, r, file_priv);
 	if (IS_ERR(fb))
@@ -387,7 +390,7 @@ int drm_mode_addfb2_ioctl(struct drm_device *dev,
 		 * ADDFB.
 		 */
 		DRM_DEBUG_KMS("addfb2 broken on bigendian");
-		return -EINVAL;
+		return -EOPNOTSUPP;
 	}
 #endif
 	return drm_mode_addfb2(dev, data, file_priv);
@@ -432,7 +435,7 @@ int drm_mode_rmfb(struct drm_device *dev, u32 fb_id,
 	int found = 0;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	fb = drm_framebuffer_lookup(dev, file_priv, fb_id);
 	if (!fb)
@@ -509,7 +512,7 @@ int drm_mode_getfb(struct drm_device *dev,
 	int ret;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	fb = drm_framebuffer_lookup(dev, file_priv, r->fb_id);
 	if (!fb)
@@ -582,7 +585,7 @@ int drm_mode_dirtyfb_ioctl(struct drm_device *dev,
 	int ret;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	fb = drm_framebuffer_lookup(dev, file_priv, r->fb_id);
 	if (!fb)

drivers/gpu/drm/drm_gem.c

@@ -667,7 +667,7 @@ drm_gem_close_ioctl(struct drm_device *dev, void *data,
 	int ret;
 
 	if (!drm_core_check_feature(dev, DRIVER_GEM))
-		return -ENODEV;
+		return -EOPNOTSUPP;
 
 	ret = drm_gem_handle_delete(file_priv, args->handle);
 
@@ -694,7 +694,7 @@ drm_gem_flink_ioctl(struct drm_device *dev, void *data,
 	int ret;
 
 	if (!drm_core_check_feature(dev, DRIVER_GEM))
-		return -ENODEV;
+		return -EOPNOTSUPP;
 
 	obj = drm_gem_object_lookup(file_priv, args->handle);
 	if (obj == NULL)
@@ -745,7 +745,7 @@ drm_gem_open_ioctl(struct drm_device *dev, void *data,
 	u32 handle;
 
 	if (!drm_core_check_feature(dev, DRIVER_GEM))
-		return -ENODEV;
+		return -EOPNOTSUPP;
 
 	mutex_lock(&dev->object_name_lock);
 	obj = idr_find(&dev->object_name_idr, (int) args->name);

drivers/gpu/drm/drm_ioctl.c

@@ -248,7 +248,7 @@ static int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_
 
 	/* Other caps only work with KMS drivers */
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -ENOTSUPP;
+		return -EOPNOTSUPP;
 
 	switch (req->capability) {
 	case DRM_CAP_DUMB_BUFFER:
@@ -319,7 +319,7 @@ drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
 		break;
 	case DRM_CLIENT_CAP_ATOMIC:
 		if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
-			return -EINVAL;
+			return -EOPNOTSUPP;
 		if (req->value > 1)
 			return -EINVAL;
 		file_priv->atomic = req->value;

drivers/gpu/drm/drm_irq.c

@@ -104,7 +104,7 @@ int drm_irq_install(struct drm_device *dev, int irq)
 	unsigned long sh_flags = 0;
 
 	if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (irq == 0)
 		return -EINVAL;
@@ -175,7 +175,7 @@ int drm_irq_uninstall(struct drm_device *dev)
 	int i;
 
 	if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	irq_enabled = dev->irq_enabled;
 	dev->irq_enabled = false;

drivers/gpu/drm/drm_lease.c

@@ -506,7 +506,7 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev,
 
 	/* Can't lease without MODESET */
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	/* Do not allow sub-leases */
 	if (lessor->lessor)
@@ -615,7 +615,7 @@ int drm_mode_list_lessees_ioctl(struct drm_device *dev,
 
 	/* Can't lease without MODESET */
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	DRM_DEBUG_LEASE("List lessees for %d\n", lessor->lessee_id);
 
@@ -671,7 +671,7 @@ int drm_mode_get_lease_ioctl(struct drm_device *dev,
 
 	/* Can't lease without MODESET */
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	DRM_DEBUG_LEASE("get lease for %d\n", lessee->lessee_id);
 
@@ -726,7 +726,7 @@ int drm_mode_revoke_lease_ioctl(struct drm_device *dev,
 
 	/* Can't lease without MODESET */
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	mutex_lock(&dev->mode_config.idr_mutex);
 

drivers/gpu/drm/drm_lock.c

@@ -166,7 +166,7 @@ int drm_legacy_lock(struct drm_device *dev, void *data,
 	int ret = 0;
 
 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	++file_priv->lock_count;
 
@@ -256,7 +256,7 @@ int drm_legacy_unlock(struct drm_device *dev, void *data, struct drm_file *file_
 	struct drm_master *master = file_priv->master;
 
 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (lock->context == DRM_KERNEL_CONTEXT) {
 		DRM_ERROR("Process %d using kernel context %d\n",

drivers/gpu/drm/drm_mode_config.c

@@ -97,8 +97,7 @@ int drm_mode_getresources(struct drm_device *dev, void *data,
 	struct drm_connector_list_iter conn_iter;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
-
+		return -EOPNOTSUPP;
 
 	mutex_lock(&file_priv->fbs_lock);
 	count = 0;

drivers/gpu/drm/drm_mode_object.c

@@ -381,7 +381,7 @@ int drm_mode_obj_get_properties_ioctl(struct drm_device *dev, void *data,
 	int ret = 0;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	drm_modeset_lock_all(dev);
 
@@ -504,7 +504,7 @@ int drm_mode_obj_set_property_ioctl(struct drm_device *dev, void *data,
 	int ret = -EINVAL;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	arg_obj = drm_mode_object_find(dev, file_priv, arg->obj_id, arg->obj_type);
 	if (!arg_obj)

drivers/gpu/drm/drm_pci.c

@@ -182,14 +182,14 @@ int drm_irq_by_busid(struct drm_device *dev, void *data,
 	struct drm_irq_busid *p = data;
 
 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	/* UMS was only ever support on PCI devices. */
 	if (WARN_ON(!dev->pdev))
 		return -EINVAL;
 
 	if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	return drm_pci_irq_by_busid(dev, p);
 }

drivers/gpu/drm/drm_plane.c

@@ -477,7 +477,7 @@ int drm_mode_getplane_res(struct drm_device *dev, void *data,
 	int count = 0;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	plane_ptr = u64_to_user_ptr(plane_resp->plane_id_ptr);
 
@@ -514,7 +514,7 @@ int drm_mode_getplane(struct drm_device *dev, void *data,
 	uint32_t __user *format_ptr;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	plane = drm_plane_find(dev, file_priv, plane_resp->plane_id);
 	if (!plane)
@@ -781,7 +781,7 @@ int drm_mode_setplane(struct drm_device *dev, void *data,
 	int ret;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	/*
 	 * First, find the plane, crtc, and fb objects.  If not available,
@@ -919,7 +919,7 @@ static int drm_mode_cursor_common(struct drm_device *dev,
 	int ret = 0;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!req->flags || (~DRM_MODE_CURSOR_FLAGS & req->flags))
 		return -EINVAL;
@@ -1023,7 +1023,7 @@ int drm_mode_page_flip_ioctl(struct drm_device *dev,
 	int ret = -EINVAL;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (page_flip->flags & ~DRM_MODE_PAGE_FLIP_FLAGS)
 		return -EINVAL;

drivers/gpu/drm/drm_prime.c

@@ -844,7 +844,7 @@ int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data,
 	struct drm_prime_handle *args = data;
 
 	if (!drm_core_check_feature(dev, DRIVER_PRIME))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!dev->driver->prime_handle_to_fd)
 		return -ENOSYS;
@@ -863,7 +863,7 @@ int drm_prime_fd_to_handle_ioctl(struct drm_device *dev, void *data,
 	struct drm_prime_handle *args = data;
 
 	if (!drm_core_check_feature(dev, DRIVER_PRIME))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!dev->driver->prime_fd_to_handle)
 		return -ENOSYS;

drivers/gpu/drm/drm_property.c

@@ -464,7 +464,7 @@ int drm_mode_getproperty_ioctl(struct drm_device *dev,
 	uint64_t __user *values_ptr;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	property = drm_property_find(dev, file_priv, out_resp->prop_id);
 	if (!property)
@@ -757,7 +757,7 @@ int drm_mode_getblob_ioctl(struct drm_device *dev,
 	int ret = 0;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	blob = drm_property_lookup_blob(dev, out_resp->blob_id);
 	if (!blob)
@@ -786,7 +786,7 @@ int drm_mode_createblob_ioctl(struct drm_device *dev,
 	int ret = 0;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	blob = drm_property_create_blob(dev, out_resp->length, NULL);
 	if (IS_ERR(blob))
@@ -823,7 +823,7 @@ int drm_mode_destroyblob_ioctl(struct drm_device *dev,
 	int ret = 0;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	blob = drm_property_lookup_blob(dev, out_resp->blob_id);
 	if (!blob)

drivers/gpu/drm/drm_scatter.c

@@ -89,10 +89,10 @@ int drm_legacy_sg_alloc(struct drm_device *dev, void *data,
 	DRM_DEBUG("\n");
 
 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!drm_core_check_feature(dev, DRIVER_SG))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (dev->sg)
 		return -EINVAL;
@@ -202,10 +202,10 @@ int drm_legacy_sg_free(struct drm_device *dev, void *data,
 	struct drm_sg_mem *entry;
 
 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!drm_core_check_feature(dev, DRIVER_SG))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	entry = dev->sg;
 	dev->sg = NULL;

drivers/gpu/drm/drm_syncobj.c

@@ -573,7 +573,7 @@ drm_syncobj_create_ioctl(struct drm_device *dev, void *data,
 	struct drm_syncobj_create *args = data;
 
 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
-		return -ENODEV;
+		return -EOPNOTSUPP;
 
 	/* no valid flags yet */
 	if (args->flags & ~DRM_SYNCOBJ_CREATE_SIGNALED)
@@ -590,7 +590,7 @@ drm_syncobj_destroy_ioctl(struct drm_device *dev, void *data,
 	struct drm_syncobj_destroy *args = data;
 
 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
-		return -ENODEV;
+		return -EOPNOTSUPP;
 
 	/* make sure padding is empty */
 	if (args->pad)
@@ -605,7 +605,7 @@ drm_syncobj_handle_to_fd_ioctl(struct drm_device *dev, void *data,
 	struct drm_syncobj_handle *args = data;
 
 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
-		return -ENODEV;
+		return -EOPNOTSUPP;
 
 	if (args->pad)
 		return -EINVAL;
@@ -629,7 +629,7 @@ drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data,
 	struct drm_syncobj_handle *args = data;
 
 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
-		return -ENODEV;
+		return -EOPNOTSUPP;
 
 	if (args->pad)
 		return -EINVAL;
@@ -921,7 +921,7 @@ drm_syncobj_wait_ioctl(struct drm_device *dev, void *data,
 	int ret = 0;
 
 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
-		return -ENODEV;
+		return -EOPNOTSUPP;
 
 	if (args->flags & ~(DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL |
 			    DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT))
@@ -955,7 +955,7 @@ drm_syncobj_reset_ioctl(struct drm_device *dev, void *data,
 	int ret;
 
 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
-		return -ENODEV;
+		return -EOPNOTSUPP;
 
 	if (args->pad != 0)
 		return -EINVAL;
@@ -988,7 +988,7 @@ drm_syncobj_signal_ioctl(struct drm_device *dev, void *data,
 	int ret;
 
 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
-		return -ENODEV;
+		return -EOPNOTSUPP;
 
 	if (args->pad != 0)
 		return -EINVAL;

drivers/gpu/drm/drm_vblank.c

@@ -1771,7 +1771,7 @@ int drm_crtc_get_sequence_ioctl(struct drm_device *dev, void *data,
 	int ret;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!dev->irq_enabled)
 		return -EINVAL;
@@ -1829,7 +1829,7 @@ int drm_crtc_queue_sequence_ioctl(struct drm_device *dev, void *data,
 	unsigned long spin_flags;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
-		return -EINVAL;
+		return -EOPNOTSUPP;
 
 	if (!dev->irq_enabled)
 		return -EINVAL;

drivers/gpu/drm/i915/i915_drv.c

@@ -1384,14 +1384,14 @@ int i915_driver_load(struct pci_dev *pdev, const struct pci_device_id *ent)
 	struct drm_i915_private *dev_priv;
 	int ret;
 
-	/* Enable nuclear pageflip on ILK+ */
-	if (!i915_modparams.nuclear_pageflip && match_info->gen < 5)
-		driver.driver_features &= ~DRIVER_ATOMIC;
-
 	dev_priv = i915_driver_create(pdev, ent);
 	if (!dev_priv)
 		return -ENOMEM;
 
+	/* Disable nuclear pageflip by default on pre-ILK */
+	if (!i915_modparams.nuclear_pageflip && match_info->gen < 5)
+		dev_priv->drm.driver_features &= ~DRIVER_ATOMIC;
+
 	ret = pci_enable_device(pdev);
 	if (ret)
 		goto out_fini;

drivers/gpu/drm/i915/intel_display.c

@@ -6685,22 +6685,20 @@ intel_reduce_m_n_ratio(uint32_t *num, uint32_t *den)
 
 static void compute_m_n(unsigned int m, unsigned int n,
 			uint32_t *ret_m, uint32_t *ret_n,
-			bool reduce_m_n)
+			bool constant_n)
 {
 	/*
-	 * Reduce M/N as much as possible without loss in precision. Several DP
-	 * dongles in particular seem to be fussy about too large *link* M/N
-	 * values. The passed in values are more likely to have the least
-	 * significant bits zero than M after rounding below, so do this first.
+	 * Several DP dongles in particular seem to be fussy about
+	 * too large link M/N values. Give N value as 0x8000 that
+	 * should be acceptable by specific devices. 0x8000 is the
+	 * specified fixed N value for asynchronous clock mode,
+	 * which the devices expect also in synchronous clock mode.
 	 */
-	if (reduce_m_n) {
-		while ((m & 1) == 0 && (n & 1) == 0) {
-			m >>= 1;
-			n >>= 1;
-		}
-	}
+	if (constant_n)
+		*ret_n = 0x8000;
+	else
+		*ret_n = min_t(unsigned int, roundup_pow_of_two(n), DATA_LINK_N_MAX);
 
-	*ret_n = min_t(unsigned int, roundup_pow_of_two(n), DATA_LINK_N_MAX);
 	*ret_m = div_u64((uint64_t) m * *ret_n, n);
 	intel_reduce_m_n_ratio(ret_m, ret_n);
 }
@@ -6709,18 +6707,18 @@ void
 intel_link_compute_m_n(int bits_per_pixel, int nlanes,
 		       int pixel_clock, int link_clock,
 		       struct intel_link_m_n *m_n,
-		       bool reduce_m_n)
+		       bool constant_n)
 {
 	m_n->tu = 64;
 
 	compute_m_n(bits_per_pixel * pixel_clock,
 		    link_clock * nlanes * 8,
 		    &m_n->gmch_m, &m_n->gmch_n,
-		    reduce_m_n);
+		    constant_n);
 
 	compute_m_n(pixel_clock, link_clock,
 		    &m_n->link_m, &m_n->link_n,
-		    reduce_m_n);
+		    constant_n);
 }
 
 static inline bool intel_panel_use_ssc(struct drm_i915_private *dev_priv)

drivers/gpu/drm/i915/intel_display.h

@@ -405,7 +405,7 @@ struct intel_link_m_n {
 void intel_link_compute_m_n(int bpp, int nlanes,
 			    int pixel_clock, int link_clock,
 			    struct intel_link_m_n *m_n,
-			    bool reduce_m_n);
+			    bool constant_n);
 
 bool is_ccs_modifier(u64 modifier);
 #endif

drivers/gpu/drm/i915/intel_dp.c

@@ -1998,8 +1998,8 @@ intel_dp_compute_config(struct intel_encoder *encoder,
 	struct intel_connector *intel_connector = intel_dp->attached_connector;
 	struct intel_digital_connector_state *intel_conn_state =
 		to_intel_digital_connector_state(conn_state);
-	bool reduce_m_n = drm_dp_has_quirk(&intel_dp->desc,
-					   DP_DPCD_QUIRK_LIMITED_M_N);
+	bool constant_n = drm_dp_has_quirk(&intel_dp->desc,
+					   DP_DPCD_QUIRK_CONSTANT_N);
 
 	if (HAS_PCH_SPLIT(dev_priv) && !HAS_DDI(dev_priv) && port != PORT_A)
 		pipe_config->has_pch_encoder = true;
@@ -2064,7 +2064,7 @@ intel_dp_compute_config(struct intel_encoder *encoder,
 			       adjusted_mode->crtc_clock,
 			       pipe_config->port_clock,
 			       &pipe_config->dp_m_n,
-			       reduce_m_n);
+			       constant_n);
 
 	if (intel_connector->panel.downclock_mode != NULL &&
 		dev_priv->drrs.type == SEAMLESS_DRRS_SUPPORT) {
@@ -2074,7 +2074,7 @@ intel_dp_compute_config(struct intel_encoder *encoder,
 					       intel_connector->panel.downclock_mode->clock,
 					       pipe_config->port_clock,
 					       &pipe_config->dp_m2_n2,
-					       reduce_m_n);
+					       constant_n);
 	}
 
 	if (!HAS_DDI(dev_priv))

drivers/gpu/drm/i915/intel_dp_mst.c

@@ -45,8 +45,8 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder,
 	int lane_count, slots;
 	const struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
 	int mst_pbn;
-	bool reduce_m_n = drm_dp_has_quirk(&intel_dp->desc,
-					   DP_DPCD_QUIRK_LIMITED_M_N);
+	bool constant_n = drm_dp_has_quirk(&intel_dp->desc,
+					   DP_DPCD_QUIRK_CONSTANT_N);
 
 	if (adjusted_mode->flags & DRM_MODE_FLAG_DBLSCAN)
 		return false;
@@ -87,7 +87,7 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder,
 			       adjusted_mode->crtc_clock,
 			       pipe_config->port_clock,
 			       &pipe_config->dp_m_n,
-			       reduce_m_n);
+			       constant_n);
 
 	pipe_config->dp_m_n.tu = slots;
 

drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c

@@ -417,6 +417,14 @@ static const struct sun8i_hdmi_phy_variant sun8i_h3_hdmi_phy = {
 	.phy_config = &sun8i_hdmi_phy_config_h3,
 };
 
+static const struct sun8i_hdmi_phy_variant sun8i_r40_hdmi_phy = {
+	.has_phy_clk = true,
+	.has_second_pll = true,
+	.phy_init = &sun8i_hdmi_phy_init_h3,
+	.phy_disable = &sun8i_hdmi_phy_disable_h3,
+	.phy_config = &sun8i_hdmi_phy_config_h3,
+};
+
 static const struct of_device_id sun8i_hdmi_phy_of_table[] = {
 	{
 		.compatible = "allwinner,sun50i-a64-hdmi-phy",
@@ -430,6 +438,10 @@ static const struct of_device_id sun8i_hdmi_phy_of_table[] = {
 		.compatible = "allwinner,sun8i-h3-hdmi-phy",
 		.data = &sun8i_h3_hdmi_phy,
 	},
+	{
+		.compatible = "allwinner,sun8i-r40-hdmi-phy",
+		.data = &sun8i_r40_hdmi_phy,
+	},
 	{ /* sentinel */ }
 };
 

drivers/gpu/drm/virtio/virtgpu_drv.h

@@ -36,6 +36,7 @@
 #include <drm/drm_atomic.h>
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_encoder.h>
+#include <drm/drm_fb_helper.h>
 #include <drm/ttm/ttm_bo_api.h>
 #include <drm/ttm/ttm_bo_driver.h>
 #include <drm/ttm/ttm_placement.h>
@@ -133,6 +134,13 @@ struct virtio_gpu_framebuffer {
 #define to_virtio_gpu_framebuffer(x) \
 	container_of(x, struct virtio_gpu_framebuffer, base)
 
+struct virtio_gpu_fbdev {
+	struct drm_fb_helper           helper;
+	struct virtio_gpu_framebuffer  vgfb;
+	struct virtio_gpu_device       *vgdev;
+	struct delayed_work            work;
+};
+
 struct virtio_gpu_mman {
 	struct ttm_bo_global_ref        bo_global_ref;
 	struct drm_global_reference	mem_global_ref;

drivers/gpu/drm/virtio/virtgpu_fb.c

@@ -29,13 +29,6 @@
 
 #define VIRTIO_GPU_FBCON_POLL_PERIOD (HZ / 60)
 
-struct virtio_gpu_fbdev {
-	struct drm_fb_helper           helper;
-	struct virtio_gpu_framebuffer  vgfb;
-	struct virtio_gpu_device       *vgdev;
-	struct delayed_work            work;
-};
-
 static int virtio_gpu_dirty_update(struct virtio_gpu_framebuffer *fb,
 				   bool store, int x, int y,
 				   int width, int height)

drivers/gpu/drm/virtio/virtgpu_vq.c

@@ -490,6 +490,15 @@ void virtio_gpu_cmd_transfer_to_host_2d(struct virtio_gpu_device *vgdev,
 {
 	struct virtio_gpu_transfer_to_host_2d *cmd_p;
 	struct virtio_gpu_vbuffer *vbuf;
+	struct virtio_gpu_fbdev *vgfbdev = vgdev->vgfbdev;
+	struct virtio_gpu_framebuffer *fb = &vgfbdev->vgfb;
+	struct virtio_gpu_object *obj = gem_to_virtio_gpu_obj(fb->base.obj[0]);
+	bool use_dma_api = !virtio_has_iommu_quirk(vgdev->vdev);
+
+	if (use_dma_api)
+		dma_sync_sg_for_device(vgdev->vdev->dev.parent,
+				       obj->pages->sgl, obj->pages->nents,
+				       DMA_TO_DEVICE);
 
 	cmd_p = virtio_gpu_alloc_cmd(vgdev, &vbuf, sizeof(*cmd_p));
 	memset(cmd_p, 0, sizeof(*cmd_p));
@@ -789,6 +798,15 @@ void virtio_gpu_cmd_transfer_to_host_3d(struct virtio_gpu_device *vgdev,
 {
 	struct virtio_gpu_transfer_host_3d *cmd_p;
 	struct virtio_gpu_vbuffer *vbuf;
+	struct virtio_gpu_fbdev *vgfbdev = vgdev->vgfbdev;
+	struct virtio_gpu_framebuffer *fb = &vgfbdev->vgfb;
+	struct virtio_gpu_object *obj = gem_to_virtio_gpu_obj(fb->base.obj[0]);
+	bool use_dma_api = !virtio_has_iommu_quirk(vgdev->vdev);
+
+	if (use_dma_api)
+		dma_sync_sg_for_device(vgdev->vdev->dev.parent,
+				       obj->pages->sgl, obj->pages->nents,
+				       DMA_TO_DEVICE);
 
 	cmd_p = virtio_gpu_alloc_cmd(vgdev, &vbuf, sizeof(*cmd_p));
 	memset(cmd_p, 0, sizeof(*cmd_p));

include/drm/drm_device.h

@@ -45,6 +45,16 @@ struct drm_device {
 	/* currently active master for this device. Protected by master_mutex */
 	struct drm_master *master;
 
+	/**
+	 * @driver_features: per-device driver features
+	 *
+	 * Drivers can clear specific flags here to disallow
+	 * certain features on a per-device basis while still
+	 * sharing a single &struct drm_driver instance across
+	 * all devices.
+	 */
+	u32 driver_features;
+
 	/**
 	 * @unplugged:
 	 *

include/drm/drm_dp_helper.h

@@ -1261,12 +1261,12 @@ int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc,
  */
 enum drm_dp_quirk {
 	/**
-	 * @DP_DPCD_QUIRK_LIMITED_M_N:
+	 * @DP_DPCD_QUIRK_CONSTANT_N:
 	 *
 	 * The device requires main link attributes Mvid and Nvid to be limited
-	 * to 16 bits.
+	 * to 16 bits. So will give a constant value (0x8000) for compatability.
 	 */
-	DP_DPCD_QUIRK_LIMITED_M_N,
+	DP_DPCD_QUIRK_CONSTANT_N,
 };
 
 /**

include/drm/drm_drv.h

@@ -653,14 +653,14 @@ static inline bool drm_dev_is_unplugged(struct drm_device *dev)
  * @dev: DRM device to check
  * @feature: feature flag
  *
- * This checks @dev for driver features, see &drm_driver.driver_features and the
- * various DRIVER_\* flags.
+ * This checks @dev for driver features, see &drm_driver.driver_features,
+ * &drm_device.driver_features, and the various DRIVER_\* flags.
  *
  * Returns true if the @feature is supported, false otherwise.
  */
-static inline bool drm_core_check_feature(struct drm_device *dev, int feature)
+static inline bool drm_core_check_feature(struct drm_device *dev, u32 feature)
 {
-	return dev->driver->driver_features & feature;
+	return dev->driver->driver_features & dev->driver_features & feature;
 }
 
 /**