At Tue, 10 Feb 2015 23:03:14 -0600, Chris Rorvick wrote:
Put an upper bound on how long we will wait for the device to respond to a read/write request (i.e., 100 milliseconds) and return an error if this is reached.
Signed-off-by: Chris Rorvick chris@rorvick.com
Applied, thanks.
Takashi
sound/usb/line6/driver.c | 29 +++++++++++++++++++++++------ 1 file changed, 23 insertions(+), 6 deletions(-)
diff --git a/sound/usb/line6/driver.c b/sound/usb/line6/driver.c index 222c14f..2a33f3e 100644 --- a/sound/usb/line6/driver.c +++ b/sound/usb/line6/driver.c @@ -297,6 +297,7 @@ static void line6_data_received(struct urb *urb) }
#define LINE6_READ_WRITE_STATUS_DELAY 2 /* milliseconds */ +#define LINE6_READ_WRITE_MAX_RETRIES 50
/* Read data from device. @@ -307,6 +308,7 @@ int line6_read_data(struct usb_line6 *line6, u16 address, void *data, struct usb_device *usbdev = line6->usbdev; int ret; unsigned char len;
unsigned count;
/* query the serial number: */ ret = usb_control_msg(usbdev, usb_sndctrlpipe(usbdev, 0), 0x67,
@@ -320,7 +322,7 @@ int line6_read_data(struct usb_line6 *line6, u16 address, void *data, }
/* Wait for data length. We'll get 0xff until length arrives. */
- do {
for (count = 0; count < LINE6_READ_WRITE_MAX_RETRIES; count++) { mdelay(LINE6_READ_WRITE_STATUS_DELAY);
ret = usb_control_msg(usbdev, usb_rcvctrlpipe(usbdev, 0), 0x67,
@@ -333,9 +335,16 @@ int line6_read_data(struct usb_line6 *line6, u16 address, void *data, "receive length failed (error %d)\n", ret); return ret; }
} while (len == 0xff);
if (len != datalen) {
if (len != 0xff)break;- }
- if (len == 0xff) {
dev_err(line6->ifcdev, "read failed after %d retries\n",count);return -EIO;- } else if (len != datalen) { /* should be equal or something went wrong */ dev_err(line6->ifcdev, "length mismatch (expected %d, got %d)\n",
@@ -367,6 +376,7 @@ int line6_write_data(struct usb_line6 *line6, u16 address, void *data, struct usb_device *usbdev = line6->usbdev; int ret; unsigned char status;
int count;
ret = usb_control_msg(usbdev, usb_sndctrlpipe(usbdev, 0), 0x67, USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
@@ -379,7 +389,7 @@ int line6_write_data(struct usb_line6 *line6, u16 address, void *data, return ret; }
- do {
for (count = 0; count < LINE6_READ_WRITE_MAX_RETRIES; count++) { mdelay(LINE6_READ_WRITE_STATUS_DELAY);
ret = usb_control_msg(usbdev, usb_rcvctrlpipe(usbdev, 0),
@@ -394,9 +404,16 @@ int line6_write_data(struct usb_line6 *line6, u16 address, void *data, "receiving status failed (error %d)\n", ret); return ret; }
} while (status == 0xff);
if (status != 0) {
if (status != 0xff)break;- }
- if (status == 0xff) {
dev_err(line6->ifcdev, "write failed after %d retries\n",count);return -EIO;- } else if (status != 0) { dev_err(line6->ifcdev, "write failed (error %d)\n", ret); return -EINVAL; }
-- 2.1.0