lkml.org 
[lkml]   [2017]   [Nov]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 1/2] drm/vc4: Account for interrupts in flight
Date
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@gmail.com>
Fixes: d5b1a78a772f ("drm/vc4: Add support for drawing 3D frames.")
---
drivers/gpu/drm/vc4/vc4_irq.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/vc4/vc4_irq.c b/drivers/gpu/drm/vc4/vc4_irq.c
index 7d7af3a..61b2e53 100644
--- a/drivers/gpu/drm/vc4/vc4_irq.c
+++ b/drivers/gpu/drm/vc4/vc4_irq.c
@@ -208,6 +208,9 @@
{
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 @@
/* 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);
}

--
1.9.1
\
 
 \ /
  Last update: 2017-11-10 02:07    [W:0.123 / U:0.524 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site