Messages in this thread Patch in this message | | | Date | Mon, 16 Feb 2004 15:16:21 +0000 | From | Paulo Marques <> | Subject | Re: [linux-usb-devel] Re: [BUG] usblp_write spins forever after an error |
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Greg KH wrote:
> On Sun, Feb 15, 2004 at 01:55:32PM -0800, Andy Lutomirski wrote: > >>I recently cancelled a print job with the printer's cancel function, and >>the CUPS backend got stuck in usblp_write (using 100% CPU and not >>responding to signals). >>
I wrote a patch some time ago to correct a bug exactly at usblp_write. It is still not in the main kernel, but you can give it a try and see if it helps. It applies cleanly against 2.6.2-rc2, but I guess it should apply to 2.6.2-rc3.
This patch corrected a problem for me, that happened when a printer presents an out-of-paper status while printing a document. The driver would send endless garbage to the printer.
I hope this helps,
-- Paulo Marques - www.grupopie.com "In a world without walls and fences who needs windows and gates?" --- drivers/usb/class/usblp.c.orig 2004-02-09 14:46:27.000000000 +0000 +++ drivers/usb/class/usblp.c 2004-02-09 15:03:32.281551096 +0000 @@ -603,7 +603,7 @@ static ssize_t usblp_write(struct file * { DECLARE_WAITQUEUE(wait, current); struct usblp *usblp = file->private_data; - int timeout, err = 0; + int timeout, err = 0, transfer_length; size_t writecount = 0; while (writecount < count) { @@ -654,19 +654,13 @@ static ssize_t usblp_write(struct file * continue; } - writecount += usblp->writeurb->transfer_buffer_length; - usblp->writeurb->transfer_buffer_length = 0; + transfer_length=(count - writecount); + if (transfer_length > USBLP_BUF_SIZE) + transfer_length = USBLP_BUF_SIZE; - if (writecount == count) { - up (&usblp->sem); - break; - } + usblp->writeurb->transfer_buffer_length = transfer_length; - usblp->writeurb->transfer_buffer_length = (count - writecount) < USBLP_BUF_SIZE ? - (count - writecount) : USBLP_BUF_SIZE; - - if (copy_from_user(usblp->writeurb->transfer_buffer, buffer + writecount, - usblp->writeurb->transfer_buffer_length)) { + if (copy_from_user(usblp->writeurb->transfer_buffer, buffer + writecount, transfer_length)) { up(&usblp->sem); return writecount ? writecount : -EFAULT; } @@ -683,6 +677,8 @@ static ssize_t usblp_write(struct file * break; } up (&usblp->sem); + + writecount += transfer_length; } return count; | |