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V4L/DVB (12755): af9015: improve usb control message function slightly 

* define names for few values
* decrease buffer len by one byte which was not used
* add check for buffer overflow for sure
* indentation fixes
* remove useless 0 len check from memcpy
It should not happen and if it happens memcpy should not do anything.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Antti Palosaari 2009-09-12 20:46:30 -03:00 committed by Mauro Carvalho Chehab
parent 9c86327809
commit 06565d7a42
1 changed files with 24 additions and 8 deletions
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32
drivers/media/dvb/dvb-usb/af9015.c
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@ -61,10 +61,13 @@ static struct af9013_config af9015_af9013_config[] = {
static int af9015_rw_udev(struct usb_device *udev, struct req_t *req)
{
#define BUF_LEN 63
#define REQ_HDR_LEN 8 /* send header size */
#define ACK_HDR_LEN 2 /* rece header size */
int act_len, ret;
u8 buf[64];
u8 buf[BUF_LEN];
u8 write = 1;
u8 msg_len = 8;
u8 msg_len = REQ_HDR_LEN;
static u8 seq; /* packet sequence number */
if (mutex_lock_interruptible(&af9015_usb_mutex) < 0)
@ -107,17 +110,26 @@ static int af9015_rw_udev(struct usb_device *udev, struct req_t *req)
goto error_unlock;
}
/* buffer overflow check */
if ((write && (req->data_len > BUF_LEN - REQ_HDR_LEN)) ||
(!write && (req->data_len > BUF_LEN - ACK_HDR_LEN))) {
err("too much data; cmd:%d len:%d", req->cmd, req->data_len);
ret = -EINVAL;
goto error_unlock;
}
/* write requested */
if (write) {
memcpy(&buf[8], req->data, req->data_len);
memcpy(&buf[REQ_HDR_LEN], req->data, req->data_len);
msg_len += req->data_len;
}
deb_xfer(">>> ");
debug_dump(buf, msg_len, deb_xfer);
/* send req */
ret = usb_bulk_msg(udev, usb_sndbulkpipe(udev, 0x02), buf, msg_len,
&act_len, AF9015_USB_TIMEOUT);
&act_len, AF9015_USB_TIMEOUT);
if (ret)
err("bulk message failed:%d (%d/%d)", ret, msg_len, act_len);
else
@ -130,10 +142,14 @@ static int af9015_rw_udev(struct usb_device *udev, struct req_t *req)
if (req->cmd == DOWNLOAD_FIRMWARE || req->cmd == RECONNECT_USB)
goto exit_unlock;
/* receive ack and data if read req */
msg_len = 1 + 1 + req->data_len; /* seq + status + data len */
/* write receives seq + status = 2 bytes
read receives seq + status + data = 2 + N bytes */
msg_len = ACK_HDR_LEN;
if (!write)
msg_len += req->data_len;
ret = usb_bulk_msg(udev, usb_rcvbulkpipe(udev, 0x81), buf, msg_len,
&act_len, AF9015_USB_TIMEOUT);
&act_len, AF9015_USB_TIMEOUT);
if (ret) {
err("recv bulk message failed:%d", ret);
ret = -1;
@ -159,7 +175,7 @@ static int af9015_rw_udev(struct usb_device *udev, struct req_t *req)
/* read request, copy returned data to return buf */
if (!write)
memcpy(req->data, &buf[2], req->data_len);
memcpy(req->data, &buf[ACK_HDR_LEN], req->data_len);
error_unlock:
exit_unlock: