* [PATCH] usb: at91_udc: correct hanging while disconnecting usb cable
@ 2007-12-06 11:07 Nicolas Ferre
2007-12-06 16:02 ` David Brownell
0 siblings, 1 reply; 2+ messages in thread
From: Nicolas Ferre @ 2007-12-06 11:07 UTC (permalink / raw)
To: David Brownell
Cc: Andrew Victor, Patrice VILCHEZ, ARM Linux Mailing List,
Linux Kernel list
Correct hanging while disconnecting the USB device
cable. Prevent a race between vbus and UDP interrupts.
This bug was tracked on at91sam9260ek boards.
Signed-off-by: Nicolas Ferre <nicolas.ferre@rfo.atmel.com>
---
A usb resume interrupt was firing after the vbus
interrupt : the IP was then already stoped and not able
to deal with it (no more clock). A simple interrupt disabling
is ok as the "end of bus reset" irq is non maskable and ok
to resume the USB device IP.
--- a/drivers/usb/gadget/at91_udc.c
+++ b/drivers/usb/gadget/at91_udc.c
@@ -908,6 +908,7 @@ static void pullup(struct at91_udc *udc,
if (is_on) {
clk_on(udc);
+ at91_udp_write(udc, AT91_UDP_ICR, AT91_UDP_RXRSM);
at91_udp_write(udc, AT91_UDP_TXVC, 0);
if (cpu_is_at91rm9200())
at91_set_gpio_value(udc->board.pullup_pin, 1);
@@ -925,6 +926,7 @@ static void pullup(struct at91_udc *udc,
}
} else {
stop_activity(udc);
+ at91_udp_write(udc, AT91_UDP_IDR, AT91_UDP_RXRSM);
at91_udp_write(udc, AT91_UDP_TXVC, AT91_UDP_TXVC_TXVDIS);
if (cpu_is_at91rm9200())
at91_set_gpio_value(udc->board.pullup_pin, 0);
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] usb: at91_udc: correct hanging while disconnecting usb cable
2007-12-06 11:07 [PATCH] usb: at91_udc: correct hanging while disconnecting usb cable Nicolas Ferre
@ 2007-12-06 16:02 ` David Brownell
0 siblings, 0 replies; 2+ messages in thread
From: David Brownell @ 2007-12-06 16:02 UTC (permalink / raw)
To: Nicolas Ferre
Cc: Andrew Victor, Patrice VILCHEZ, ARM Linux Mailing List,
Linux Kernel list
On Thursday 06 December 2007, Nicolas Ferre wrote:
> Correct hanging while disconnecting the USB device
> cable. Prevent a race between vbus and UDP interrupts.
> This bug was tracked on at91sam9260ek boards.
>
> Signed-off-by: Nicolas Ferre <nicolas.ferre@rfo.atmel.com>
> ---
>
> A usb resume interrupt was firing after the vbus
> interrupt : the IP was then already stoped and not able
> to deal with it (no more clock). A simple interrupt disabling
> is ok as the "end of bus reset" irq is non maskable and ok
> to resume the USB device IP.
Good, thanks for finding this. The bug was reported
recently, and obviously can't be reproduced except on
boards which *have* a VBUS interrupt!
I've signed off on this and suggested Greg merge it
before the 2.6.24-final freeze.
- Dave
^ permalink raw reply [flat|nested] 2+ messages in thread
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2007-12-06 11:07 [PATCH] usb: at91_udc: correct hanging while disconnecting usb cable Nicolas Ferre
2007-12-06 16:02 ` David Brownell
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