lkml.org 
[lkml]   [2008]   [Aug]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
SubjectRe: USB Serial device disconnect causes IRQ disable after using ehci controller halted
Date
On Tuesday 26 August 2008, Alan Stern wrote:
> While it certainly would be a good idea to prevent the handshake
> failures from occurring in the first place -- Dave, aren't you working
> on a patch for that? -- we should also make sure that when they do
> occur, the controller gets reset properly.  And an error message should
> be printed in the log.

Like this?

Greg, please queue for 2.6.27 unless someone finds a
problem with this patch.


========= SNIP! SNIP! SNIPPITY SNIP!
From: David Brownell <dbrownell@users.sourceforge.net>
I noticed that the "Refactor "if (handshake()) state = HC_STATE_HALT"
patch from earlier this year perpetuated a potential problem: it can
mark the controller as halted when it's still running (but not acting
as, perhaps wrongly, expected).
That caused some hangs and crashes, rather than more polite failure
modes of a truly halted controller. This patch forces a true halt,
and emits a (previously missing) diagnostic.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
---
drivers/usb/host/ehci-hcd.c | 26 ++++++++++++++++----------
1 file changed, 16 insertions(+), 10 deletions(-)
--- a/drivers/usb/host/ehci-hcd.c 2008-08-15 14:04:27.000000000 -0700
+++ b/drivers/usb/host/ehci-hcd.c 2008-08-15 14:04:36.000000000 -0700
@@ -145,16 +145,6 @@ static int handshake (struct ehci_hcd *e
return -ETIMEDOUT;
}

-static int handshake_on_error_set_halt(struct ehci_hcd *ehci, void __iomem *ptr,
- u32 mask, u32 done, int usec)
-{
- int error = handshake(ehci, ptr, mask, done, usec);
- if (error)
- ehci_to_hcd(ehci)->state = HC_STATE_HALT;
-
- return error;
-}
-
/* force HC to halt state from unknown (EHCI spec section 2.3) */
static int ehci_halt (struct ehci_hcd *ehci)
{
@@ -173,6 +163,22 @@ static int ehci_halt (struct ehci_hcd *e
STS_HALT, STS_HALT, 16 * 125);
}

+static int handshake_on_error_set_halt(struct ehci_hcd *ehci, void __iomem *ptr,
+ u32 mask, u32 done, int usec)
+{
+ int error;
+
+ error = handshake(ehci, ptr, mask, done, usec);
+ if (error) {
+ ehci_halt(ehci);
+ ehci_to_hcd(ehci)->state = HC_STATE_HALT;
+ ehci_err(ehci, "force halt; handhake %p %08x %08x -> %d\n",
+ ptr, mask, done, error);
+ }
+
+ return error;
+}
+
/* put TDI/ARC silicon into EHCI mode */
static void tdi_reset (struct ehci_hcd *ehci)
{

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2008-08-26 23:47    [from the cache]
©2003-2011 Jasper Spaans. Advertise on this site