On Sun, 11 Jul 2010, Bob Copeland wrote: > Good idea. I didn't save the output, but the 'dma already free' > error happens in the error path after the initialization already > failed, so that's probably a red herring. The transfer sequence > looked like: > > send cmd 1 > recv ack > send cmd 2 > recv -> -EPIPE > > The recv side isn't using us->iobuf after all, it's the second > use of a driver-allocated buffer. > > This patch fixes it for me, what do you think? > > From: Bob Copeland <me@xxxxxxxxxxxxxxx> > Date: Sun, 11 Jul 2010 09:21:56 -0400 > Subject: [PATCH] usb: initialize transfer flags in usb storage > > Commit 0ede76fcec5415ef82a423a95120286895822e2d, "USB: remove uses of > URB_NO_SETUP_DMA_MAP" introduced a regression by inadvertantly removing > initialization of the transfer flags. This caused initialization > failures in the ums-karma driver. > > Signed-off-by: Bob Copeland <me@xxxxxxxxxxxxxxx> > --- > drivers/usb/storage/transport.c | 1 + > 1 files changed, 1 insertions(+), 0 deletions(-) > > diff --git a/drivers/usb/storage/transport.c b/drivers/usb/storage/transport.c > index 4471642..c17b7b0 100644 > --- a/drivers/usb/storage/transport.c > +++ b/drivers/usb/storage/transport.c > @@ -142,6 +142,7 @@ static int usb_stor_msg_common(struct us_data *us, int timeout) > us->current_urb->actual_length = 0; > us->current_urb->error_count = 0; > us->current_urb->status = 0; > + us->current_urb->transfer_flags = 0; > > /* we assume that if transfer_buffer isn't us->iobuf then it > * hasn't been mapped for DMA. Yes, this is clunky, but it's Yep, that looks right. The URB_NO_TRANSFER_DMA_MAP flag is getting set but never cleared. While you're at it, you could remove the lines that reset actual_length, error_count, and status. The core takes care of actual_length and status when an URB is submitted, and error_count is used only for isochronous URBs. Kind of ironic that the driver was resetting a bunch of flags that didn't need it but ignoring the one flag that did! Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
