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authorBen Skeggs <bskeggs@redhat.com>2010-03-15 23:45:07 +0100
committerBen Skeggs <bskeggs@redhat.com>2010-04-09 02:20:15 +0200
commit8e024f13142fbbca5fbe14a6926516a45bd70c3a (patch)
tree3b9300b6afa1f0bd180ecf7be91a65c185ddf712 /drivers
parentdrm/nv50: implement gpio set/get routines (diff)
downloadlinux-8e024f13142fbbca5fbe14a6926516a45bd70c3a.tar.xz
linux-8e024f13142fbbca5fbe14a6926516a45bd70c3a.zip
drm/nouveau: bail out of auxch transaction if we repeatedly recieve defers
There's one known case where we never stop recieving DEFER, and loop here forever. Lets not do that.. Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/gpu/drm/nouveau/nouveau_dp.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/gpu/drm/nouveau/nouveau_dp.c b/drivers/gpu/drm/nouveau/nouveau_dp.c
index f954ad93e81f..deeb21c6865c 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dp.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dp.c
@@ -483,7 +483,7 @@ nouveau_dp_auxch(struct nouveau_i2c_chan *auxch, int cmd, int addr,
ctrl |= (cmd << NV50_AUXCH_CTRL_CMD_SHIFT);
ctrl |= ((data_nr - 1) << NV50_AUXCH_CTRL_LEN_SHIFT);
- for (;;) {
+ for (i = 0; i < 16; i++) {
nv_wr32(dev, NV50_AUXCH_CTRL(index), ctrl | 0x80000000);
nv_wr32(dev, NV50_AUXCH_CTRL(index), ctrl);
nv_wr32(dev, NV50_AUXCH_CTRL(index), ctrl | 0x00010000);
@@ -502,6 +502,12 @@ nouveau_dp_auxch(struct nouveau_i2c_chan *auxch, int cmd, int addr,
break;
}
+ if (i == 16) {
+ NV_ERROR(dev, "auxch DEFER too many times, bailing\n");
+ ret = -EREMOTEIO;
+ goto out;
+ }
+
if (cmd & 1) {
if ((stat & NV50_AUXCH_STAT_COUNT) != data_nr) {
ret = -EREMOTEIO;