From: iceberg Date: Fri, 21 Jan 2011 18:00:25 +0000 (-0300) Subject: [media] double mutex lock in drivers/media/radio/si470x/radio-si470x- X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=2b97e2201eb76d56c4901d39e8ed276f2de0e2e9;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git [media] double mutex lock in drivers/media/radio/si470x/radio-si470x- KERNEL_VERSION: 2.6.37 common.c in function ssize_t si470x_fops_read. 1. First mutex_lock on &radio->lock in line 441 2. Second in line 462 I think that mutex in line 462 is not needed. 433static ssize_t si470x_fops_read(struct file *file, char __user *buf, 434 size_t count, loff_t *ppos) 435{ .... 441 mutex_lock(&radio->lock); 442 if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0) 443 si470x_rds_on(radio); 444 445 /* block if no new data available */ 446 while (radio->wr_index == radio->rd_index) { 447 if (file->f_flags & O_NONBLOCK) { 448 retval = -EWOULDBLOCK; 449 goto done; 450 } 451 if (wait_event_interruptible(radio->read_queue, 452 radio->wr_index != radio->rd_index) < 0) { 453 retval = -EINTR; 454 goto done; 455 } 456 } 457 458 /* calculate block count from byte count */ 459 count /= 3; 460 461 /* copy RDS block out of internal buffer and to user buffer */ 462 mutex_lock(&radio->lock); Found by Linux Device Drivers Verification Project Remove second mutex. Signed-off-by: Alexander Strakh Signed-off-by: Mauro Carvalho Chehab --- diff --git a/drivers/media/radio/si470x/radio-si470x-common.c b/drivers/media/radio/si470x/radio-si470x-common.c index 60c176fe328e..38ae6cd65790 100644 --- a/drivers/media/radio/si470x/radio-si470x-common.c +++ b/drivers/media/radio/si470x/radio-si470x-common.c @@ -460,7 +460,6 @@ static ssize_t si470x_fops_read(struct file *file, char __user *buf, count /= 3; /* copy RDS block out of internal buffer and to user buffer */ - mutex_lock(&radio->lock); while (block_count < count) { if (radio->rd_index == radio->wr_index) break;