On Wed, Jun 3, 2009 at 11:05, Sergei Shtylyov wrote:
> Mike Frysinger wrote:
>> From: Bryan Wu <cooloney@xxxxxxxxxx>
>> Some USB stick does not answer PING correctly which will make USB enumeration fail.
>> We enable the NAK limit value to detect this PING issue, then disable the PING option
>> for such ill-behaviored usb sticks.
>
> You're effectively only doing this during the sattus stage. Is that enough?
>
>> diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
>> index 4000cf6..6f0b471 100644
>> --- a/drivers/usb/musb/musb_core.c
>> +++ b/drivers/usb/musb/musb_core.c
>> @@ -571,6 +571,7 @@ static irqreturn_t musb_stage0_irq(struct musb *musb, u8 int_usb,
>> handled = IRQ_HANDLED;
>> musb->is_active = 1;
>> set_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
>> + musb->disable_ping = 0;
>>
>> musb->ep0_stage = MUSB_EP0_START;
>>
>> diff --git a/drivers/usb/musb/musb_core.h b/drivers/usb/musb/musb_core.h
>> index efb39b5..db013dd 100644
>> --- a/drivers/usb/musb/musb_core.h
>> +++ b/drivers/usb/musb/musb_core.h
>> @@ -386,6 +386,9 @@ struct musb {
>> unsigned is_multipoint:1;
>> unsigned ignore_disconnect:1; /* during bus resets */
>>
>> + /* Disable PING packet to cope with ill-behaved usb thumb drives. */
>> + unsigned disable_ping:1;
>> +
>> #ifdef C_MP_TX
>> unsigned bulk_split:1;
>> #define can_bulk_split(musb,type) \
>> diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
>> index db1b574..a0b3423 100644
>> --- a/drivers/usb/musb/musb_host.c
>> +++ b/drivers/usb/musb/musb_host.c
>> @@ -1026,6 +1026,11 @@ irqreturn_t musb_h_ep0_irq(struct musb *musb)
>> } else if (csr & MUSB_CSR0_H_NAKTIMEOUT) {
>> DBG(2, "control NAK timeout\n");
>>
>> + /* For some ill-behaved USB stick, control transfer should
>> + * disable PING packet
>> + */
>> + musb->disable_ping = 1;
>> +
>> /* NOTE: this code path would be a good place to PAUSE a
>> * control transfer, if another one is queued, so that
>> * ep0 is more likely to stay busy. That's already done
>> @@ -1085,6 +1090,8 @@ irqreturn_t musb_h_ep0_irq(struct musb *musb)
>> else
>> csr = MUSB_CSR0_H_STATUSPKT
>> | MUSB_CSR0_TXPKTRDY;
>> + if (musb->disable_ping)
>> + csr |= MUSB_CSR0_H_DIS_PING;
>
> This fails to set the DIS PING bit set if musb_h_ep_continus() returns
> non-zero above, i.e. during the data transfers.
Cliff can take a look ...
-mike
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