From 1e4cd78ed4932b08bc839392fa6784e03d8f9619 Mon Sep 17 00:00:00 2001
From: Thomas Zimmermann <tzimmermann@suse.de>
Date: Fri, 25 Jun 2021 10:21:59 +0200
Subject: [PATCH] drm: Don't test for IRQ support in VBLANK ioctls
Git-commit: 1e4cd78ed4932b08bc839392fa6784e03d8f9619
Patch-mainline: v5.15-rc1
References: bsc#1195464
For KMS drivers, replace the IRQ check in VBLANK ioctls with a check for
vblank support. IRQs might be enabled wthout vblanking being supported.
This change also removes the DRM framework's only dependency on IRQ state
for non-legacy drivers. For legacy drivers with userspace modesetting,
the original test remains in drm_wait_vblank_ioctl().
V4: * avoid preprocessor ifdef in drm_wait_vblank_ioctl() (Jani, Thierry)
V3: * optimize test in drm_wait_vblank_ioctl() for KMS case (Liviu) * update docs for drm_irq_uninstall()
V2: * keep the old test for legacy drivers in drm_wait_vblank_ioctl() (Daniel)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210625082222.3845-5-tzimmermann@suse.de
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/gpu/drm/drm_irq.c | 13 ++++---------
drivers/gpu/drm/drm_vblank.c | 15 ++++++++++++---
2 files changed, 16 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index c3bd664ea733..945dd82e2ea3 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -74,10 +74,8 @@
* only supports devices with a single interrupt on the main device stored in
* &drm_device.dev and set as the device paramter in drm_dev_alloc().
*
- * These IRQ helpers are strictly optional. Drivers which roll their own only
- * need to set &drm_device.irq_enabled to signal the DRM core that vblank
- * interrupts are working. Since these helpers don't automatically clean up the
- * requested interrupt like e.g. devm_request_irq() they're not really
+ * These IRQ helpers are strictly optional. Since these helpers don't automatically
+ * clean up the requested interrupt like e.g. devm_request_irq() they're not really
* recommended.
*/
@@ -91,9 +89,7 @@
* and after the installation.
*
* This is the simplified helper interface provided for drivers with no special
- * needs. Drivers which need to install interrupt handlers for multiple
- * interrupts must instead set &drm_device.irq_enabled to signal the DRM core
- * that vblank interrupts are available.
+ * needs.
*
* @irq must match the interrupt number that would be passed to request_irq(),
* if called directly instead of using this helper function.
@@ -156,8 +152,7 @@ EXPORT_SYMBOL(drm_irq_install);
*
* Calls the driver's &drm_driver.irq_uninstall function and unregisters the IRQ
* handler. This should only be called by drivers which used drm_irq_install()
- * to set up their interrupt handler. Other drivers must only reset
- * &drm_device.irq_enabled to false.
+ * to set up their interrupt handler.
*
* Note that for kernel modesetting drivers it is a bug if this function fails.
* The sanity checks are only to catch buggy user modesetting drivers which call
diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
index 3417e1ac7918..bba6781cc48f 100644
--- a/drivers/gpu/drm/drm_vblank.c
+++ b/drivers/gpu/drm/drm_vblank.c
@@ -1737,6 +1737,15 @@ static void drm_wait_vblank_reply(struct drm_device *dev, unsigned int pipe,
reply->tval_usec = ts.tv_nsec / 1000;
}
+static bool drm_wait_vblank_supported(struct drm_device *dev)
+{
+ if (IS_ENABLED(CONFIG_DRM_LEGACY)) {
+ if (unlikely(drm_core_check_feature(dev, DRIVER_LEGACY)))
+ return dev->irq_enabled;
+ }
+ return drm_dev_has_vblank(dev);
+}
+
int drm_wait_vblank_ioctl(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
@@ -1748,7 +1757,7 @@ int drm_wait_vblank_ioctl(struct drm_device *dev, void *data,
unsigned int pipe_index;
unsigned int flags, pipe, high_pipe;
- if (!dev->irq_enabled)
+ if (!drm_wait_vblank_supported(dev))
return -EOPNOTSUPP;
if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
@@ -2023,7 +2032,7 @@ int drm_crtc_get_sequence_ioctl(struct drm_device *dev, void *data,
if (!drm_core_check_feature(dev, DRIVER_MODESET))
return -EOPNOTSUPP;
- if (!dev->irq_enabled)
+ if (!drm_dev_has_vblank(dev))
return -EOPNOTSUPP;
crtc = drm_crtc_find(dev, file_priv, get_seq->crtc_id);
@@ -2082,7 +2091,7 @@ int drm_crtc_queue_sequence_ioctl(struct drm_device *dev, void *data,
if (!drm_core_check_feature(dev, DRIVER_MODESET))
return -EOPNOTSUPP;
- if (!dev->irq_enabled)
+ if (!drm_dev_has_vblank(dev))
return -EOPNOTSUPP;
crtc = drm_crtc_find(dev, file_priv, queue_seq->crtc_id);
--
2.31.1