[PATCH] NFC: nxp-nci: fix deadlock between firmware download and IRQ handler

[Ian Ray]

The firmware download work function holds `info_lock' while calling the
nxp_nci_fw_send(), which waits for a completion.

The completion is signalled by the IRQ thread handler, which also takes
`info_lock', causing a deadlock.

Fix by dropping the mutex while waiting for the completion.

Signed-off-by: Ian Ray <ian.ray@xxxxxxxxxxxxxxxx>
---
 drivers/nfc/nxp-nci/firmware.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/nfc/nxp-nci/firmware.c b/drivers/nfc/nxp-nci/firmware.c
index a9533977aff8..38fcac26ce56 100644
--- a/drivers/nfc/nxp-nci/firmware.c
+++ b/drivers/nfc/nxp-nci/firmware.c
@@ -154,8 +154,13 @@ static int nxp_nci_fw_send(struct nxp_nci_info *info)
 		if (fw_info->fw)
 			schedule_work(&fw_info->work);
 	} else {
+		mutex_unlock(&info->info_lock);
+
 		completion_rc = wait_for_completion_interruptible_timeout(
 			&fw_info->cmd_completion, NXP_NCI_FW_ANSWER_TIMEOUT);
+
+		mutex_lock(&info->info_lock);
+
 		if (completion_rc == 0)
 			return -ETIMEDOUT;
 	}
-- 
2.47.3