openwrtv4/target/linux/brcm2708/patches-4.9/950-0162-drm-vc4-Fix-termination-of-the-initial-scan-for-bran.patch
Rafał Miłecki fce21ae4cc brcm2708: rename all patches from raspberrypi git tree to use 950 prefix
Right now all brcm2708 patches are extracted from the non-mainline
raspberrypi/linux git tree. Many of them are hacks and/or are unneeded
in LEDE. Raspberry Pi is getting better and better mainline support so
it would be nice to finally start maintaining patches in a cleaner way:
1) Backport patches accepted in upstream tree
2) Start using upstream drivers
3) Pick only these patches that are needed for more complete support

Handling above tasks requires grouping patches - ideally using the same
prefixes as generic ones. It means we should rename existing patches to
use some high prefix. This will allow e.g. use 0xx for backported code.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Stijn Tintel <stijn@linux-ipv6.be>
2017-03-24 08:06:35 +01:00

68 lines
2.4 KiB
Diff

From 57b0774967d7ea8d4173f82387100a84e4ba05d8 Mon Sep 17 00:00:00 2001
From: Eric Anholt <eric@anholt.net>
Date: Thu, 20 Oct 2016 16:48:12 -0700
Subject: [PATCH] drm/vc4: Fix termination of the initial scan for branch
targets.
The loop is scanning until the original max_ip (size of the BO), but
we want to not examine any code after the PROG_END's delay slots.
There was a block trying to do that, except that we had some early
continue statements if the signal wasn't a PROG_END or a BRANCH.
The failure mode would be that a valid shader is rejected because some
undefined memory after the PROG_END slots is parsed as a branch and
the rest of its setup is illegal. I haven't seen this in the wild,
but valgrind was complaining when about this up in the userland
simulator mode.
Signed-off-by: Eric Anholt <eric@anholt.net>
(cherry picked from commit 457e67a728696c4f8e6423c64e93def50530db9a)
---
drivers/gpu/drm/vc4/vc4_validate_shaders.c | 19 ++++++++-----------
1 file changed, 8 insertions(+), 11 deletions(-)
--- a/drivers/gpu/drm/vc4/vc4_validate_shaders.c
+++ b/drivers/gpu/drm/vc4/vc4_validate_shaders.c
@@ -608,9 +608,7 @@ static bool
vc4_validate_branches(struct vc4_shader_validation_state *validation_state)
{
uint32_t max_branch_target = 0;
- bool found_shader_end = false;
int ip;
- int shader_end_ip = 0;
int last_branch = -2;
for (ip = 0; ip < validation_state->max_ip; ip++) {
@@ -621,8 +619,13 @@ vc4_validate_branches(struct vc4_shader_
uint32_t branch_target_ip;
if (sig == QPU_SIG_PROG_END) {
- shader_end_ip = ip;
- found_shader_end = true;
+ /* There are two delay slots after program end is
+ * signaled that are still executed, then we're
+ * finished. validation_state->max_ip is the
+ * instruction after the last valid instruction in the
+ * program.
+ */
+ validation_state->max_ip = ip + 3;
continue;
}
@@ -676,15 +679,9 @@ vc4_validate_branches(struct vc4_shader_
}
set_bit(after_delay_ip, validation_state->branch_targets);
max_branch_target = max(max_branch_target, after_delay_ip);
-
- /* There are two delay slots after program end is signaled
- * that are still executed, then we're finished.
- */
- if (found_shader_end && ip == shader_end_ip + 2)
- break;
}
- if (max_branch_target > shader_end_ip) {
+ if (max_branch_target > validation_state->max_ip - 3) {
DRM_ERROR("Branch landed after QPU_SIG_PROG_END");
return false;
}