2008-03-21 23:10:48

by Chris Wright

[permalink] [raw]
Subject: [patch 56/76] USB: ehci: handle large bulk URBs correctly (again)

-stable review patch. If anyone has any objections, please let us know.
---------------------

From: Misha Zhilin <[email protected]>

When use of urb->status in the EHCI driver was reworked last August
(commit 14c04c0f88f228fee1f412be91d6edcb935c78aa), a bug was inserted
in the handling of early completion for bulk transactions that need
more than one qTD (e.g. more than 20KB in one URB).

This patch resolves that problem by ensuring that the early completion
status is preserved until the URB is handed back to its submitter,
instead of resetting it after each qTD.

Signed-off-by: Misha Zhilin <[email protected]>
Signed-off-by: David Brownell <[email protected]>
Acked-by: Alan Stern <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Chris Wright <[email protected]>
---
drivers/usb/host/ehci-q.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/usb/host/ehci-q.c
+++ b/drivers/usb/host/ehci-q.c
@@ -315,10 +315,10 @@ qh_completions (struct ehci_hcd *ehci, s
if (likely (last->urb != urb)) {
ehci_urb_done(ehci, last->urb, last_status);
count++;
+ last_status = -EINPROGRESS;
}
ehci_qtd_free (ehci, last);
last = NULL;
- last_status = -EINPROGRESS;
}

/* ignore urbs submitted during completions we reported */

--