From: Andre Herms Date: Thu, 19 Nov 2009 17:14:49 +0000 (+0100) Subject: USB: usbtmc: repeat usb_bulk_msg until whole message is transfered X-Git-Tag: firefly_0821_release~11625^2~584 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=f4c0cf18d2b21dd614662c3b95ce0ffd0a4aa881;p=firefly-linux-kernel-4.4.55.git USB: usbtmc: repeat usb_bulk_msg until whole message is transfered commit ec412b92dbe3ea839716853eea058d1bcc5e6ca4 upstream. usb_bulk_msg() transfers only bytes up to the maximum packet size. It must be repeated by the usbtmc driver until all bytes of a TMC message are transfered. Without this patch, ETIMEDOUT is reported when writing TMC messages larger than the maximum USB bulk size and the transfer remains incomplete. The user will notice that the device hangs and must be reset by either closing the application or pulling the plug. Signed-off-by: Andre Herms Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c index 2473cf0c6b1d..d9461c91b8c9 100644 --- a/drivers/usb/class/usbtmc.c +++ b/drivers/usb/class/usbtmc.c @@ -562,10 +562,16 @@ static ssize_t usbtmc_write(struct file *filp, const char __user *buf, n_bytes = roundup(12 + this_part, 4); memset(buffer + 12 + this_part, 0, n_bytes - (12 + this_part)); - retval = usb_bulk_msg(data->usb_dev, - usb_sndbulkpipe(data->usb_dev, - data->bulk_out), - buffer, n_bytes, &actual, USBTMC_TIMEOUT); + do { + retval = usb_bulk_msg(data->usb_dev, + usb_sndbulkpipe(data->usb_dev, + data->bulk_out), + buffer, n_bytes, + &actual, USBTMC_TIMEOUT); + if (retval != 0) + break; + n_bytes -= actual; + } while (n_bytes); data->bTag_last_write = data->bTag; data->bTag++;