From 8937669fd637e2edff05973cb1fdee5f910cbcc7 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Tue, 24 Sep 2013 15:48:05 -0400 Subject: [PATCH] USB: iMX21: accept very late isochronous URBs Commit 24f531371de1 (USB: EHCI: accept very late isochronous URBs) changed the isochronous API provided by ehci-hcd. URBs submitted too late, so that the time slots for all their packets have already expired, are no longer rejected outright. Instead the submission is accepted, and the URB completes normally with a -EXDEV error for each packet. This is what client drivers expect. The same policy should be implemented in imx21-hcd, but I don't know enough about the hardware to do it. As a second-best substitute, this patch treats very late isochronous submissions as though the URB_ISO_ASAP flag were set. I don't have any way to test this change, unfortunately. Signed-off-by: Alan Stern CC: Sascha Hauer CC: Martin Fuzzey Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/imx21-hcd.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/usb/host/imx21-hcd.c b/drivers/usb/host/imx21-hcd.c index 60a5de505ca1..adb01d950a16 100644 --- a/drivers/usb/host/imx21-hcd.c +++ b/drivers/usb/host/imx21-hcd.c @@ -824,13 +824,13 @@ static int imx21_hc_urb_enqueue_isoc(struct usb_hcd *hcd, i = DIV_ROUND_UP(wrap_frame( cur_frame - urb->start_frame), urb->interval); - if (urb->transfer_flags & URB_ISO_ASAP) { + + /* Treat underruns as if URB_ISO_ASAP was set */ + if ((urb->transfer_flags & URB_ISO_ASAP) || + i >= urb->number_of_packets) { urb->start_frame = wrap_frame(urb->start_frame + i * urb->interval); i = 0; - } else if (i >= urb->number_of_packets) { - ret = -EXDEV; - goto alloc_dmem_failed; } } }