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Subject[PATCH 8/9] [media] vp702x: use preallocated buffer in vp702x_usb_inout_cmd
Date
If we need a bigger buffer, we reallocte a new buffer and free the old
one.

Note: This change is tested to compile only as I don't have the
hardware.

Signed-off-by: Florian Mickler <florian@mickler.org>
---
drivers/media/dvb/dvb-usb/vp702x.c | 23 +++++++++++++++++++----
1 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/drivers/media/dvb/dvb-usb/vp702x.c b/drivers/media/dvb/dvb-usb/vp702x.c
index 6dd50bc..54355f8 100644
--- a/drivers/media/dvb/dvb-usb/vp702x.c
+++ b/drivers/media/dvb/dvb-usb/vp702x.c
@@ -116,13 +116,28 @@ int vp702x_usb_inout_op(struct dvb_usb_device *d, u8 *o, int olen, u8 *i, int il
static int vp702x_usb_inout_cmd(struct dvb_usb_device *d, u8 cmd, u8 *o,
int olen, u8 *i, int ilen, int msec)
{
+ struct vp702x_device_state *st = d->priv;
int ret = 0;
u8 *buf;
int buflen = max(olen + 2, ilen + 1);

- buf = kmalloc(buflen, GFP_KERNEL);
- if (!buf)
- return -ENOMEM;
+ ret = mutex_lock_interruptible(&st->buf_mutex);
+ if (ret < 0)
+ return ret;
+
+ if (buflen > st->buf_len) {
+ buf = kmalloc(buflen, GFP_KERNEL);
+ if (!buf) {
+ mutex_unlock(&st->buf_mutex);
+ return -ENOMEM;
+ }
+ info("successfully reallocated a bigger buffer");
+ kfree(st->buf);
+ st->buf = buf;
+ st->buf_len = buflen;
+ } else {
+ buf = st->buf;
+ }

buf[0] = 0x00;
buf[1] = cmd;
@@ -132,8 +147,8 @@ static int vp702x_usb_inout_cmd(struct dvb_usb_device *d, u8 cmd, u8 *o,

if (ret == 0)
memcpy(i, &buf[1], ilen);
+ mutex_unlock(&st->buf_mutex);

- kfree(buf);
return ret;
}

--
1.7.4.1


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