diff options
| author | Chris Rorvick <chris@rorvick.com> | 2015-02-11 06:03:14 +0100 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2015-02-11 10:37:30 +0100 |
| commit | f3dfd1be08cc55f930f32e714fb1967630c47991 (patch) | |
| tree | d150f709d2a8d9ad4015db521e1ae376c36cf18b /sound/usb/line6 | |
| parent | ALSA: line6: Add delay before reading status (diff) | |
| download | linux-f3dfd1be08cc55f930f32e714fb1967630c47991.tar.xz linux-f3dfd1be08cc55f930f32e714fb1967630c47991.zip | |
ALSA: line6: Return error if device not responding
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>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/usb/line6')
| -rw-r--r-- | sound/usb/line6/driver.c | 29 |
1 files changed, 23 insertions, 6 deletions
diff --git a/sound/usb/line6/driver.c b/sound/usb/line6/driver.c index 2f9b74e7accb..f2ee8046271a 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, int 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, int 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, int 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, int 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, int 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, int 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; } |