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authorQiang Yu <quic_qianyu@quicinc.com>2023-12-11 09:42:52 +0300
committerManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>2023-12-16 08:24:29 +0300
commit01bd694ac2f682fb8017e16148b928482bc8fa4b (patch)
tree1247cd426e4cee168210732d0a2b983ab21ccbd5 /drivers/bus
parentb89b6a863dd53bc70d8e52d50f9cfaef8ef5e9c9 (diff)
downloadlinux-01bd694ac2f682fb8017e16148b928482bc8fa4b.tar.xz
bus: mhi: host: Drop chan lock before queuing buffers
Ensure read and write locks for the channel are not taken in succession by dropping the read lock from parse_xfer_event() such that a callback given to client can potentially queue buffers and acquire the write lock in that process. Any queueing of buffers should be done without channel read lock acquired as it can result in multiple locks and a soft lockup. Cc: <stable@vger.kernel.org> # 5.7 Fixes: 1d3173a3bae7 ("bus: mhi: core: Add support for processing events from client device") Signed-off-by: Qiang Yu <quic_qianyu@quicinc.com> Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com> Tested-by: Jeffrey Hugo <quic_jhugo@quicinc.com> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Link: https://lore.kernel.org/r/1702276972-41296-3-git-send-email-quic_qianyu@quicinc.com [mani: added fixes tag and cc'ed stable] Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Diffstat (limited to 'drivers/bus')
-rw-r--r--drivers/bus/mhi/host/main.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c
index ad7807e4b523..abb561db9ae1 100644
--- a/drivers/bus/mhi/host/main.c
+++ b/drivers/bus/mhi/host/main.c
@@ -644,6 +644,8 @@ static int parse_xfer_event(struct mhi_controller *mhi_cntrl,
mhi_del_ring_element(mhi_cntrl, tre_ring);
local_rp = tre_ring->rp;
+ read_unlock_bh(&mhi_chan->lock);
+
/* notify client */
mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);
@@ -669,6 +671,8 @@ static int parse_xfer_event(struct mhi_controller *mhi_cntrl,
kfree(buf_info->cb_buf);
}
}
+
+ read_lock_bh(&mhi_chan->lock);
}
break;
} /* CC_EOT */