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