From 2d171121773e441272e242af7f268f7ea71d93d1 Mon Sep 17 00:00:00 2001
From: Jani Nikula <jani.nikula@intel.com>
Date: Tue, 11 Feb 2020 16:47:53 +0200
Subject: drm/irq: remove check on dev->dev_private
Git-commit: e62bf83aa1bb9d9953eec2e3663528c766b148ea
Patch-mainline: v5.7-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322
There is no real reason to require drivers to set and use
dev->dev_private. Indeed, the current recommendation, as documented in
drm_device.h, is to embed struct drm_device in the per-device struct
instead of using dev_private.
Remove the requirement for dev_private to have been set to indicate
driver initialization.
For background, quoting Daniel Vetter:
Now there might be some hilarious races this papers over, but:
- Proper drivers should only call drm_dev_register once everything is
set up, including this stuff here. No race possible with anything else
really.
- Slightly more wobbly drivers, including the legacy ones, all use
drm_global_mutex. This was the former BKL, which means that it was
impossible for soeone to go through the load/unload/reload (between
lastclose and firstopen) paths and also run the ioctl. But the ioctl
had to be made unlocked because blocking there killed X:
commit 8f4ff2b06afcd6f151868474a432c603057eaf56
Author: Ilija Hadzic <ihadzic@research.bell-labs.com>
Date: Mon Oct 31 17:46:18 2011 -0400
drm: do not sleep on vblank while holding a mutex
The even more legacy DRM_CONTROL ioctl stayed fully locked. But the
file open/close paths are still fully locked, and that's the only
place legacy drivers should call drm_irq_install/uninstall, so should
all still be fully ordered and protected and happy.
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel@ffwll.ch>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200211144753.3175-1-jani.nikula@intel.com
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/drm_irq.c | 4 ----
1 file changed, 4 deletions(-)
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 03bce566a8c3..588be45abd7a 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -111,10 +111,6 @@ int drm_irq_install(struct drm_device *dev, int irq)
if (irq == 0)
return -EINVAL;
- /* Driver must have been initialized */
- if (!dev->dev_private)
- return -EINVAL;
-
if (dev->irq_enabled)
return -EBUSY;
dev->irq_enabled = true;
--
2.28.0