diff mbox

[3/6] ALSA: line6: Return error if device not responding

Message ID 1423630997-25464-4-git-send-email-chris@rorvick.com (mailing list archive)
State Accepted
Commit f3dfd1be08cc55f930f32e714fb1967630c47991
Headers show

Commit Message

Chris Rorvick Feb. 11, 2015, 5:03 a.m. UTC 
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>
---
 sound/usb/line6/driver.c | 29 +++++++++++++++++++++++------
 1 file changed, 23 insertions(+), 6 deletions(-)

Comments

Takashi Iwai Feb. 11, 2015, 9:43 a.m. UTC | #1 
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
>
diff mbox

Patch

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;
 	}