From 7cc2f34e1f4da07c791737cc6b3d965b31815ea0 Mon Sep 17 00:00:00 2001 From: Eddie James Date: Tue, 3 Aug 2021 16:30:16 -0500 Subject: [PATCH] fsi: sbefifo: Use interruptible mutex locking Some SBE operations have extremely large responses and can require several minutes to process the response. During this time, the device lock must be held. If another process attempts an operation, it will wait for the mutex for longer than the kernel hung task watchdog allows. Therefore, use the interruptible function to lock the mutex. Signed-off-by: Eddie James Reviewed-by: Joel Stanley Link: https://lore.kernel.org/r/20210803213016.44739-1-eajames@linux.ibm.com Signed-off-by: Joel Stanley --- drivers/fsi/fsi-sbefifo.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/fsi/fsi-sbefifo.c b/drivers/fsi/fsi-sbefifo.c index b414ab4431ef..52328adef643 100644 --- a/drivers/fsi/fsi-sbefifo.c +++ b/drivers/fsi/fsi-sbefifo.c @@ -752,7 +752,9 @@ int sbefifo_submit(struct device *dev, const __be32 *command, size_t cmd_len, iov_iter_kvec(&resp_iter, WRITE, &resp_iov, 1, rbytes); /* Perform the command */ - mutex_lock(&sbefifo->lock); + rc = mutex_lock_interruptible(&sbefifo->lock); + if (rc) + return rc; rc = __sbefifo_submit(sbefifo, command, cmd_len, &resp_iter); mutex_unlock(&sbefifo->lock); @@ -832,7 +834,9 @@ static ssize_t sbefifo_user_read(struct file *file, char __user *buf, iov_iter_init(&resp_iter, WRITE, &resp_iov, 1, len); /* Perform the command */ - mutex_lock(&sbefifo->lock); + rc = mutex_lock_interruptible(&sbefifo->lock); + if (rc) + goto bail; rc = __sbefifo_submit(sbefifo, user->pending_cmd, cmd_len, &resp_iter); mutex_unlock(&sbefifo->lock); if (rc < 0) @@ -887,7 +891,9 @@ static ssize_t sbefifo_user_write(struct file *file, const char __user *buf, user->pending_len = 0; /* Trigger reset request */ - mutex_lock(&sbefifo->lock); + rc = mutex_lock_interruptible(&sbefifo->lock); + if (rc) + goto bail; rc = sbefifo_request_reset(user->sbefifo); mutex_unlock(&sbefifo->lock); if (rc == 0)