openwrt/target/linux/brcm2708/patches-4.4/0096-drm-vc4-Drop-struct_mutex-around-CL-validation.patch
Felix Fietkau 4224b52c3a brcm2708: add linux 4.4 support
- random-bcm2708 and spi-bcm2708 have been removed.
- sound-soc-bcm2708-i2s has been upstreamed as sound-soc-bcm2835-i2s.

Let's keep linux 4.1 for a while, since linux 4.4 appears to have some issues
with multicast traffic on RPi ethernet:
https://gist.github.com/Noltari/5b1cfdecce5ed4bc08fd

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

SVN-Revision: 48266
2016-01-17 10:42:23 +00:00

64 lines
1.8 KiB
Diff

From 6a9940a2bde49eda470e58f19a6bde3ded87d7fb Mon Sep 17 00:00:00 2001
From: Eric Anholt <eric@anholt.net>
Date: Mon, 19 Oct 2015 08:44:35 -0700
Subject: [PATCH 096/127] drm/vc4: Drop struct_mutex around CL validation.
We were using it so that we could make sure that shader validation
state didn't change while we were validating, but now shader
validation state is immutable. The bcl/rcl generation doesn't do any
other BO dereferencing, and seems to have no other global state
dependency not covered by job_lock / bo_lock.
Fixes a lock order reversal between mmap_sem and struct_mutex.
Signed-off-by: Eric Anholt <eric@anholt.net>
---
drivers/gpu/drm/vc4/vc4_gem.c | 12 ++++--------
1 file changed, 4 insertions(+), 8 deletions(-)
--- a/drivers/gpu/drm/vc4/vc4_gem.c
+++ b/drivers/gpu/drm/vc4/vc4_gem.c
@@ -244,13 +244,15 @@ static void
vc4_queue_submit(struct drm_device *dev, struct vc4_exec_info *exec)
{
struct vc4_dev *vc4 = to_vc4_dev(dev);
- uint64_t seqno = ++vc4->emit_seqno;
+ uint64_t seqno;
unsigned long irqflags;
+ spin_lock_irqsave(&vc4->job_lock, irqflags);
+
+ seqno = ++vc4->emit_seqno;
exec->seqno = seqno;
vc4_update_bo_seqnos(exec, seqno);
- spin_lock_irqsave(&vc4->job_lock, irqflags);
list_add_tail(&exec->head, &vc4->job_list);
/* If no job was executing, kick ours off. Otherwise, it'll
@@ -608,8 +610,6 @@ vc4_submit_cl_ioctl(struct drm_device *d
exec->args = args;
INIT_LIST_HEAD(&exec->unref_list);
- mutex_lock(&dev->struct_mutex);
-
ret = vc4_cl_lookup_bos(dev, file_priv, exec);
if (ret)
goto fail;
@@ -636,15 +636,11 @@ vc4_submit_cl_ioctl(struct drm_device *d
/* Return the seqno for our job. */
args->seqno = vc4->emit_seqno;
- mutex_unlock(&dev->struct_mutex);
-
return 0;
fail:
vc4_complete_exec(exec);
- mutex_unlock(&dev->struct_mutex);
-
return ret;
}