This is a note to let you know that I've just added the patch titled
drm/vc4: Account for interrupts in flight
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-vc4-account-for-interrupts-in-flight.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Thu Feb 1 13:45:42 CET 2018
From: Stefan Schake <stschake@xxxxxxxxx>
Date: Fri, 10 Nov 2017 02:05:06 +0100
Subject: drm/vc4: Account for interrupts in flight
From: Stefan Schake <stschake@xxxxxxxxx>
[ Upstream commit 253696ccd613fbdaa5aba1de44c461a058e0a114 ]
Synchronously disable the IRQ to make the following cancel_work_sync
invocation effective.
An interrupt in flight could enqueue further overflow mem work. As we
free the binner BO immediately following vc4_irq_uninstall this caused
a NULL pointer dereference in the work callback vc4_overflow_mem_work.
Link: https://github.com/anholt/linux/issues/114
Signed-off-by: Stefan Schake <stschake@xxxxxxxxx>
Fixes: d5b1a78a772f ("drm/vc4: Add support for drawing 3D frames.")
Signed-off-by: Eric Anholt <eric@xxxxxxxxxx>
Reviewed-by: Eric Anholt <eric@xxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/1510275907-993-2-git-send-email-stschake@xxxxxxxxx
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/vc4/vc4_irq.c | 6 ++++++
1 file changed, 6 insertions(+)
--- a/drivers/gpu/drm/vc4/vc4_irq.c
+++ b/drivers/gpu/drm/vc4/vc4_irq.c
@@ -208,6 +208,9 @@ vc4_irq_postinstall(struct drm_device *d
{
struct vc4_dev *vc4 = to_vc4_dev(dev);
+ /* Undo the effects of a previous vc4_irq_uninstall. */
+ enable_irq(dev->irq);
+
/* Enable both the render done and out of memory interrupts. */
V3D_WRITE(V3D_INTENA, V3D_DRIVER_IRQS);
@@ -225,6 +228,9 @@ vc4_irq_uninstall(struct drm_device *dev
/* Clear any pending interrupts we might have left. */
V3D_WRITE(V3D_INTCTL, V3D_DRIVER_IRQS);
+ /* Finish any interrupt handler still in flight. */
+ disable_irq(dev->irq);
+
cancel_work_sync(&vc4->overflow_mem_work);
}
Patches currently in stable-queue which might be from stschake@xxxxxxxxx are
queue-4.14/drm-vc4-move-irq-enable-to-pm-path.patch
queue-4.14/drm-vc4-account-for-interrupts-in-flight.patch