[media] saa6588: add support for non-blocking mode

saa6588 always blocked while waiting for data, even if the filehandle
was in non-blocking mode.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

3 files changed, 29 insertions, 21 deletions

diff --git a/drivers/media/i2c/saa6588.c b/drivers/media/i2c/saa6588.c
index 21cf940f5ea0..2960b5a8362a 100644
--- a/drivers/media/i2c/saa6588.c
+++ b/drivers/media/i2c/saa6588.c
@@ -150,14 +150,14 @@ static inline struct saa6588 *to_saa6588(struct v4l2_subdev *sd)
 
 /* ---------------------------------------------------------------------- */
 
-static int block_to_user_buf(struct saa6588 *s, unsigned char __user *user_buf)
+static bool block_from_buf(struct saa6588 *s, unsigned char *buf)
 {
         int i;
 
         if (s->rd_index == s->wr_index) {
                 if (debug > 2)
                         dprintk(PREFIX "Read: buffer empty.\n");
-                return 0;
+                return false;
         }
 
         if (debug > 2) {
@@ -166,8 +166,7 @@ static int block_to_user_buf(struct saa6588 *s, unsigned char __user *user_buf)
                         dprintk("0x%02x ", s->buffer[i]);
         }
 
-        if (copy_to_user(user_buf, &s->buffer[s->rd_index], 3))
-                return -EFAULT;
+        memcpy(buf, &s->buffer[s->rd_index], 3);
 
         s->rd_index += 3;
         if (s->rd_index >= s->buf_size)
@@ -177,22 +176,22 @@ static int block_to_user_buf(struct saa6588 *s, unsigned char __user *user_buf)
         if (debug > 2)
                 dprintk("%d blocks total.\n", s->block_count);
 
-        return 1;
+        return true;
 }
 
 static void read_from_buf(struct saa6588 *s, struct saa6588_command *a)
 {
-        unsigned long flags;
-
         unsigned char __user *buf_ptr = a->buffer;
-        unsigned int i;
+        unsigned char buf[3];
+        unsigned long flags;
         unsigned int rd_blocks;
+        unsigned int i;
 
         a->result = 0;
         if (!a->buffer)
                 return;
 
-        while (!s->data_available_for_read) {
+        while (!a->nonblocking && !s->data_available_for_read) {
                 int ret = wait_event_interruptible(s->read_queue,
                                              s->data_available_for_read);
                 if (ret == -ERESTARTSYS) {
@@ -201,24 +200,31 @@ static void read_from_buf(struct saa6588 *s, struct saa6588_command *a)
                 }
         }
 
-        spin_lock_irqsave(&s->lock, flags);
         rd_blocks = a->block_count;
+        spin_lock_irqsave(&s->lock, flags);
         if (rd_blocks > s->block_count)
                 rd_blocks = s->block_count;
+        spin_unlock_irqrestore(&s->lock, flags);
 
-        if (!rd_blocks) {
-                spin_unlock_irqrestore(&s->lock, flags);
+        if (!rd_blocks)
                 return;
-        }
 
         for (i = 0; i < rd_blocks; i++) {
-                if (block_to_user_buf(s, buf_ptr)) {
-                        buf_ptr += 3;
-                        a->result++;
-                } else
+                bool got_block;
+
+                spin_lock_irqsave(&s->lock, flags);
+                got_block = block_from_buf(s, buf);
+                spin_unlock_irqrestore(&s->lock, flags);
+                if (!got_block)
                         break;
+                if (copy_to_user(buf_ptr, buf, 3)) {
+                        a->result = -EFAULT;
+                        return;
+                }
+                buf_ptr += 3;
+                a->result += 3;
         }
-        a->result *= 3;
+        spin_lock_irqsave(&s->lock, flags);
         s->data_available_for_read = (s->block_count > 0);
         spin_unlock_irqrestore(&s->lock, flags);
 }
@@ -408,9 +414,8 @@ static long saa6588_ioctl(struct v4l2_subdev *sd, unsigned int cmd, void *arg)
                 /* --- poll() for /dev/radio --- */
         case SAA6588_CMD_POLL:
                 a->result = 0;
-                if (s->data_available_for_read) {
+                if (s->data_available_for_read)
                         a->result |= POLLIN | POLLRDNORM;
-                }
                 poll_wait(a->instance, &s->read_queue, a->event_list);
                 break;
 
diff --git a/drivers/media/pci/bt8xx/bttv-driver.c b/drivers/media/pci/bt8xx/bttv-driver.c
index 92a06fd85865..c2aaadcd9318 100644
--- a/drivers/media/pci/bt8xx/bttv-driver.c
+++ b/drivers/media/pci/bt8xx/bttv-driver.c
@@ -3266,7 +3266,9 @@ static ssize_t radio_read(struct file *file, char __user *data,
         struct bttv_fh *fh = file->private_data;
         struct bttv *btv = fh->btv;
         struct saa6588_command cmd;
-        cmd.block_count = count/3;
+
+        cmd.block_count = count / 3;
+        cmd.nonblocking = file->f_flags & O_NONBLOCK;
         cmd.buffer = data;
         cmd.instance = file;
         cmd.result = -ENODEV;
diff --git a/drivers/media/pci/saa7134/saa7134-video.c b/drivers/media/pci/saa7134/saa7134-video.c
index 88e64055f0a4..36026b1cb3f8 100644
--- a/drivers/media/pci/saa7134/saa7134-video.c
+++ b/drivers/media/pci/saa7134/saa7134-video.c
@@ -1285,6 +1285,7 @@ static ssize_t radio_read(struct file *file, char __user *data,
         struct saa6588_command cmd;
 
         cmd.block_count = count/3;
+        cmd.nonblocking = file->f_flags & O_NONBLOCK;
         cmd.buffer = data;
         cmd.instance = file;
         cmd.result = -ENODEV;