From: Bhaumik Bhatt <bbhatt@xxxxxxxxxxxxxx>
Protect WP accesses such that multiple threads queueing buffers for
incoming data do not race.
Cc: <stable@xxxxxxxxxxxxxxx>
Fixes: 189ff97cca53 ("bus: mhi: core: Add support for data transfer")
Signed-off-by: Bhaumik Bhatt <bbhatt@xxxxxxxxxxxxxx>
Signed-off-by: Qiang Yu <quic_qianyu@xxxxxxxxxxx>
---
drivers/bus/mhi/host/main.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c
index 6cf1145..c9415b0 100644
--- a/drivers/bus/mhi/host/main.c
+++ b/drivers/bus/mhi/host/main.c
@@ -1205,6 +1205,9 @@ int mhi_gen_tre(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan,
int eot, eob, chain, bei;
int ret;
+ /* Protect accesses for reading and incrementing WP */
+ write_lock_bh(&mhi_chan->lock);
+
buf_ring = &mhi_chan->buf_ring;
tre_ring = &mhi_chan->tre_ring;
@@ -1222,8 +1225,10 @@ int mhi_gen_tre(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan,
if (!info->pre_mapped) {
ret = mhi_cntrl->map_single(mhi_cntrl, buf_info);
- if (ret)
+ if (ret) {
+ write_unlock_bh(&mhi_chan->lock);
return ret;
+ }
}
eob = !!(flags & MHI_EOB);
@@ -1240,6 +1245,8 @@ int mhi_gen_tre(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan,
mhi_add_ring_element(mhi_cntrl, tre_ring);
mhi_add_ring_element(mhi_cntrl, buf_ring);
+ write_unlock_bh(&mhi_chan->lock);
+
return 0;
}
--
2.7.4
