drm/irq: Ditch DRIVER_IRQ_SHARED

This is only used by drm_irq_install(), which is an optional helper.
For legacy pci devices this is required (due to interrupt sharing without
msi/msi-x), and just making this the default exactly matches the behaviour
of all existing drivers using the drm_irq_install() helpers. In case that
ever becomes wrong drivers can roll their own irq handling, as many
drivers already do (for other reasons like needing a threaded interrupt
handler, or having an entire pile of different interrupt sources).

v2: Rebase

v3: Improve commit message (Emil)

Cc: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190129104248.26607-3-daniel.vetter@ffwll.ch

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

@@ -1189,7 +1189,7 @@ amdgpu_get_crtc_scanout_position(struct drm_device *dev, unsigned int pipe,
 static struct drm_driver kms_driver = {
 	.driver_features =
 	    DRIVER_USE_AGP | DRIVER_ATOMIC |
-	    DRIVER_IRQ_SHARED | DRIVER_GEM |
+	    DRIVER_GEM |
 	    DRIVER_PRIME | DRIVER_RENDER | DRIVER_MODESET | DRIVER_SYNCOBJ,
 	.load = amdgpu_driver_load_kms,
 	.open = amdgpu_driver_open_kms,

drivers/gpu/drm/drm_irq.c

@@ -120,8 +120,8 @@ int drm_irq_install(struct drm_device *dev, int irq)
 	if (dev->driver->irq_preinstall)
 		dev->driver->irq_preinstall(dev);
 
-	/* Install handler */
-	if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
+	/* PCI devices require shared interrupts. */
+	if (dev->pdev)
 		sh_flags = IRQF_SHARED;
 
 	ret = request_irq(irq, dev->driver->irq_handler,

drivers/gpu/drm/gma500/psb_drv.c

@@ -468,8 +468,7 @@ static const struct file_operations psb_gem_fops = {
 };
 
 static struct drm_driver driver = {
-	.driver_features = DRIVER_IRQ_SHARED | \
-			   DRIVER_MODESET | DRIVER_GEM,
+	.driver_features = DRIVER_MODESET | DRIVER_GEM,
 	.load = psb_driver_load,
 	.unload = psb_driver_unload,
 	.lastclose = drm_fb_helper_lastclose,

drivers/gpu/drm/i915/i915_drv.c

@@ -3209,7 +3209,7 @@ static struct drm_driver driver = {
 	 * deal with them for Intel hardware.
 	 */
 	.driver_features =
-	    DRIVER_IRQ_SHARED | DRIVER_GEM | DRIVER_PRIME |
+	    DRIVER_GEM | DRIVER_PRIME |
 	    DRIVER_RENDER | DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_SYNCOBJ,
 	.release = i915_driver_release,
 	.open = i915_driver_open,

drivers/gpu/drm/mga/mga_drv.c

@@ -57,7 +57,7 @@ static const struct file_operations mga_driver_fops = {
 static struct drm_driver driver = {
 	.driver_features =
 	    DRIVER_USE_AGP | DRIVER_PCI_DMA | DRIVER_LEGACY |
-	    DRIVER_HAVE_DMA | DRIVER_HAVE_IRQ | DRIVER_IRQ_SHARED,
+	    DRIVER_HAVE_DMA | DRIVER_HAVE_IRQ,
 	.dev_priv_size = sizeof(drm_mga_buf_priv_t),
 	.load = mga_driver_load,
 	.unload = mga_driver_unload,

drivers/gpu/drm/qxl/qxl_drv.c

@@ -245,7 +245,6 @@ static struct pci_driver qxl_pci_driver = {
 
 static struct drm_driver qxl_driver = {
 	.driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME |
-			   DRIVER_IRQ_SHARED |
 			   DRIVER_ATOMIC,
 
 	.dumb_create = qxl_mode_dumb_create,

drivers/gpu/drm/r128/r128_drv.c

@@ -57,7 +57,7 @@ static const struct file_operations r128_driver_fops = {
 static struct drm_driver driver = {
 	.driver_features =
 	    DRIVER_USE_AGP | DRIVER_PCI_DMA | DRIVER_SG | DRIVER_LEGACY |
-	    DRIVER_HAVE_DMA | DRIVER_HAVE_IRQ | DRIVER_IRQ_SHARED,
+	    DRIVER_HAVE_DMA | DRIVER_HAVE_IRQ,
 	.dev_priv_size = sizeof(drm_r128_buf_priv_t),
 	.load = r128_driver_load,
 	.preclose = r128_driver_preclose,

drivers/gpu/drm/radeon/radeon_drv.c

@@ -534,9 +534,7 @@ radeon_get_crtc_scanout_position(struct drm_device *dev, unsigned int pipe,
 
 static struct drm_driver kms_driver = {
 	.driver_features =
-	    DRIVER_USE_AGP |
-	    DRIVER_IRQ_SHARED | DRIVER_GEM |
-	    DRIVER_PRIME | DRIVER_RENDER,
+	    DRIVER_USE_AGP | DRIVER_GEM | DRIVER_PRIME | DRIVER_RENDER,
 	.load = radeon_driver_load_kms,
 	.open = radeon_driver_open_kms,
 	.postclose = radeon_driver_postclose_kms,

drivers/gpu/drm/via/via_drv.c

@@ -70,8 +70,7 @@ static const struct file_operations via_driver_fops = {
 
 static struct drm_driver driver = {
 	.driver_features =
-	    DRIVER_USE_AGP | DRIVER_HAVE_IRQ | DRIVER_LEGACY |
-	    DRIVER_IRQ_SHARED,
+	    DRIVER_USE_AGP | DRIVER_HAVE_IRQ | DRIVER_LEGACY,
 	.load = via_driver_load,
 	.unload = via_driver_unload,
 	.open = via_driver_open,

drivers/gpu/drm/vmwgfx/vmwgfx_drv.c

@@ -1582,7 +1582,7 @@ static const struct file_operations vmwgfx_driver_fops = {
 };
 
 static struct drm_driver driver = {
-	.driver_features = DRIVER_IRQ_SHARED |
+	.driver_features =
 	DRIVER_MODESET | DRIVER_PRIME | DRIVER_RENDER | DRIVER_ATOMIC,
 	.load = vmw_driver_load,
 	.unload = vmw_driver_unload,

drivers/staging/vboxvideo/vbox_drv.c

@@ -221,8 +221,7 @@ static void vbox_master_drop(struct drm_device *dev, struct drm_file *file_priv)
 
 static struct drm_driver driver = {
 	.driver_features =
-	    DRIVER_MODESET | DRIVER_GEM | DRIVER_IRQ_SHARED |
-	    DRIVER_PRIME | DRIVER_ATOMIC,
+	    DRIVER_MODESET | DRIVER_GEM | DRIVER_PRIME | DRIVER_ATOMIC,
 	.dev_priv_size = 0,
 
 	.lastclose = drm_fb_helper_lastclose,

include/drm/drm_drv.h

@@ -100,20 +100,20 @@ enum drm_driver_feature {
 	 * Set up DRM AGP support, see drm_agp_init(), the DRM core will manage
 	 * AGP resources. New drivers don't need this.
 	 */
-	DRIVER_USE_AGP			= BIT(24),
+	DRIVER_USE_AGP			= BIT(25),
 	/**
 	 * @DRIVER_LEGACY:
 	 *
 	 * Denote a legacy driver using shadow attach. Do not use.
 	 */
-	DRIVER_LEGACY			= BIT(25),
+	DRIVER_LEGACY			= BIT(26),
 	/**
 	 * @DRIVER_PCI_DMA:
 	 *
 	 * Driver is capable of PCI DMA, mapping of PCI DMA buffers to userspace
 	 * will be enabled. Only for legacy drivers. Do not use.
 	 */
-	DRIVER_PCI_DMA			= BIT(26),
+	DRIVER_PCI_DMA			= BIT(27),
 	/**
 	 * @DRIVER_SG:
 	 *
@@ -121,7 +121,7 @@ enum drm_driver_feature {
 	 * scatter/gather buffers will be enabled. Only for legacy drivers. Do
 	 * not use.
 	 */
-	DRIVER_SG			= BIT(27),
+	DRIVER_SG			= BIT(28),
 
 	/**
 	 * @DRIVER_HAVE_DMA:
@@ -129,7 +129,7 @@ enum drm_driver_feature {
 	 * Driver supports DMA, the userspace DMA API will be supported. Only
 	 * for legacy drivers. Do not use.
 	 */
-	DRIVER_HAVE_DMA			= BIT(28),
+	DRIVER_HAVE_DMA			= BIT(29),
 	/**
 	 * @DRIVER_HAVE_IRQ:
 	 *
@@ -139,17 +139,7 @@ enum drm_driver_feature {
 	 * drm_irq_uninstall() helper functions, or roll their own irq support
 	 * code by calling request_irq() directly.
 	 */
-	DRIVER_HAVE_IRQ			= BIT(29),
-	/**
-	 * @DRIVER_IRQ_SHARED:
-	 *
-	 * Indicates to drm_irq_install() that a shared irq should be requested.
-	 *
-	 * FIXME: This should be an explicit argument for non-legacy drivers, or
-	 * at least the default for PCI devices (which would cover all current
-	 * users).
-	 */
-	DRIVER_IRQ_SHARED		= BIT(30),
+	DRIVER_HAVE_IRQ			= BIT(30),
 	/**
 	 * @DRIVER_KMS_LEGACY_CONTEXT:
 	 *