[PATCH v6 8/8] bus: mhi: core: Do not clear channel context more than once

From: Bhaumik Bhatt
Date: Thu Feb 04 2021 - 15:34:00 EST


Clearing a channel context can happen twice if the client driver
unprepares and reset the channels from the remove() callback from
a controller requested MHI power down sequence. If there are
multiple attempts at calling the mhi_free_coherent() API, we see
kernel warnings such as "trying to free invalid coherent area".
Example for one such client is the QRTR MHI driver. Avoid these
warnings by skipping mhi_deinit_chan_ctxt() API call and prevent
extra work from MHI as the channels are already disabled.

Signed-off-by: Bhaumik Bhatt <bbhatt@xxxxxxxxxxxxxx>
---
drivers/bus/mhi/core/init.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index 30eef19..272f350 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -1314,6 +1314,7 @@ static int mhi_driver_remove(struct device *dev)

if ((ch_state[dir] == MHI_CH_STATE_ENABLED ||
ch_state[dir] == MHI_CH_STATE_STOP) &&
+ mhi_chan->ch_state != MHI_CH_STATE_DISABLED &&
!mhi_chan->offload_ch)
mhi_deinit_chan_ctxt(mhi_cntrl, mhi_chan);

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