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Message-Id: <20240506-cocci-locks-v1-1-a67952fe5d19@chromium.org>
Date: Mon, 06 May 2024 21:10:26 +0000
From: Ricardo Ribalda <ribalda@...omium.org>
To: Andy Walls <awalls@...metrocast.net>,
Mauro Carvalho Chehab <mchehab@...nel.org>, Sean Young <sean@...s.org>,
Jarod Wilson <jarod@...hat.com>
Cc: Hans Verkuil <hverkuil-cisco@...all.nl>, linux-media@...r.kernel.org,
linux-kernel@...r.kernel.org, Ricardo Ribalda <ribalda@...omium.org>
Subject: [PATCH 1/5] media: ivtv: Factor out schedule functions
Cocci is very confused by unlock-lock a mutex in the middle of a
function.
Factor the schedules out, avoid code duplication and make cocci a bit
happier.
Fix the following cocci warnings:
drivers/media/pci/ivtv/ivtv-fileops.c:223:4-10: preceding lock on line 267
drivers/media/pci/ivtv/ivtv-fileops.c:230:3-9: preceding lock on line 267
drivers/media/pci/ivtv/ivtv-fileops.c:236:4-10: preceding lock on line 267
drivers/media/pci/ivtv/ivtv-fileops.c:245:3-9: preceding lock on line 267
drivers/media/pci/ivtv/ivtv-fileops.c:251:3-9: preceding lock on line 267
drivers/media/pci/ivtv/ivtv-fileops.c:257:3-9: preceding lock on line 267
drivers/media/pci/ivtv/ivtv-fileops.c:272:3-9: preceding lock on line 267
drivers/media/pci/ivtv/ivtv-fileops.c:598:4-10: preceding lock on line 627
drivers/media/pci/ivtv/ivtv-fileops.c:598:4-10: preceding lock on line 689
drivers/media/pci/ivtv/ivtv-fileops.c:606:3-9: preceding lock on line 627
drivers/media/pci/ivtv/ivtv-fileops.c:606:3-9: preceding lock on line 689
drivers/media/pci/ivtv/ivtv-fileops.c:648:3-9: preceding lock on line 627
drivers/media/pci/ivtv/ivtv-fileops.c:648:3-9: preceding lock on line 689
drivers/media/pci/ivtv/ivtv-fileops.c:692:4-10: preceding lock on line 689
Signed-off-by: Ricardo Ribalda <ribalda@...omium.org>
---
drivers/media/pci/ivtv/ivtv-fileops.c | 66 +++++++++++++++++++++--------------
1 file changed, 39 insertions(+), 27 deletions(-)
diff --git a/drivers/media/pci/ivtv/ivtv-fileops.c b/drivers/media/pci/ivtv/ivtv-fileops.c
index 4202c3a47d33..cfa28d035586 100644
--- a/drivers/media/pci/ivtv/ivtv-fileops.c
+++ b/drivers/media/pci/ivtv/ivtv-fileops.c
@@ -21,6 +21,7 @@
#include "ivtv-ioctl.h"
#include "ivtv-cards.h"
#include "ivtv-firmware.h"
+#include <linux/lockdep.h>
#include <media/v4l2-event.h>
#include <media/i2c/saa7115.h>
@@ -190,12 +191,27 @@ static void ivtv_update_pgm_info(struct ivtv *itv)
itv->pgm_info_write_idx = (itv->pgm_info_write_idx + i) % itv->pgm_info_num;
}
+static void ivtv_schedule(struct ivtv_stream *s)
+{
+ struct ivtv *itv = s->itv;
+ DEFINE_WAIT(wait);
+
+ lockdep_assert_held(&itv->serialize_lock);
+
+ mutex_unlock(&itv->serialize_lock);
+ prepare_to_wait(&s->waitq, &wait, TASK_INTERRUPTIBLE);
+ /* New buffers might have become free before we were added to the waitqueue */
+ if (!s->q_free.buffers)
+ schedule();
+ finish_wait(&s->waitq, &wait);
+ mutex_lock(&itv->serialize_lock);
+}
+
static struct ivtv_buffer *ivtv_get_buffer(struct ivtv_stream *s, int non_block, int *err)
{
struct ivtv *itv = s->itv;
struct ivtv_stream *s_vbi = &itv->streams[IVTV_ENC_STREAM_TYPE_VBI];
struct ivtv_buffer *buf;
- DEFINE_WAIT(wait);
*err = 0;
while (1) {
@@ -258,13 +274,7 @@ static struct ivtv_buffer *ivtv_get_buffer(struct ivtv_stream *s, int non_block,
}
/* wait for more data to arrive */
- mutex_unlock(&itv->serialize_lock);
- prepare_to_wait(&s->waitq, &wait, TASK_INTERRUPTIBLE);
- /* New buffers might have become available before we were added to the waitqueue */
- if (!s->q_full.buffers)
- schedule();
- finish_wait(&s->waitq, &wait);
- mutex_lock(&itv->serialize_lock);
+ ivtv_schedule(s);
if (signal_pending(current)) {
/* return if a signal was received */
IVTV_DEBUG_INFO("User stopped %s\n", s->name);
@@ -533,6 +543,25 @@ int ivtv_start_decoding(struct ivtv_open_id *id, int speed)
return 0;
}
+static int ivtv_schedule_dma(struct ivtv_stream *s)
+{
+ struct ivtv *itv = s->itv;
+ int got_sig;
+ DEFINE_WAIT(wait);
+
+ lockdep_assert_held(&itv->serialize_lock);
+
+ mutex_unlock(&itv->serialize_lock);
+ prepare_to_wait(&itv->dma_waitq, &wait, TASK_INTERRUPTIBLE);
+ while (!(got_sig = signal_pending(current)) &&
+ test_bit(IVTV_F_S_DMA_PENDING, &s->s_flags))
+ schedule();
+ finish_wait(&itv->dma_waitq, &wait);
+ mutex_lock(&itv->serialize_lock);
+
+ return got_sig;
+}
+
static ssize_t ivtv_write(struct file *filp, const char __user *user_buf, size_t count, loff_t *pos)
{
struct ivtv_open_id *id = fh2id(filp->private_data);
@@ -544,7 +573,6 @@ static ssize_t ivtv_write(struct file *filp, const char __user *user_buf, size_t
int bytes_written = 0;
int mode;
int rc;
- DEFINE_WAIT(wait);
IVTV_DEBUG_HI_FILE("write %zd bytes to %s\n", count, s->name);
@@ -618,13 +646,7 @@ static ssize_t ivtv_write(struct file *filp, const char __user *user_buf, size_t
break;
if (filp->f_flags & O_NONBLOCK)
return -EAGAIN;
- mutex_unlock(&itv->serialize_lock);
- prepare_to_wait(&s->waitq, &wait, TASK_INTERRUPTIBLE);
- /* New buffers might have become free before we were added to the waitqueue */
- if (!s->q_free.buffers)
- schedule();
- finish_wait(&s->waitq, &wait);
- mutex_lock(&itv->serialize_lock);
+ ivtv_schedule(s);
if (signal_pending(current)) {
IVTV_DEBUG_INFO("User stopped %s\n", s->name);
return -EINTR;
@@ -674,20 +696,10 @@ static ssize_t ivtv_write(struct file *filp, const char __user *user_buf, size_t
if (test_bit(IVTV_F_S_NEEDS_DATA, &s->s_flags)) {
if (s->q_full.length >= itv->dma_data_req_size) {
- int got_sig;
-
if (mode == OUT_YUV)
ivtv_yuv_setup_stream_frame(itv);
- mutex_unlock(&itv->serialize_lock);
- prepare_to_wait(&itv->dma_waitq, &wait, TASK_INTERRUPTIBLE);
- while (!(got_sig = signal_pending(current)) &&
- test_bit(IVTV_F_S_DMA_PENDING, &s->s_flags)) {
- schedule();
- }
- finish_wait(&itv->dma_waitq, &wait);
- mutex_lock(&itv->serialize_lock);
- if (got_sig) {
+ if (ivtv_schedule_dma(s)) {
IVTV_DEBUG_INFO("User interrupted %s\n", s->name);
return -EINTR;
}
--
2.45.0.rc1.225.g2a3ae87e7f-goog
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