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SubjectRe: [PATCH v4 1/6] usb: musb: core: Handle Babble condition only in HOST mode
Hi Bin,
On 5/19/2014 9:24 PM, Bin Liu wrote:
> Hi,
>
> On Mon, May 19, 2014 at 8:39 AM, George Cherian <george.cherian@ti.com> wrote:
>> BABBLE and RESET share the same interrupt. The interrupt
>> is considered to be RESET if MUSB is in peripheral mode and
>> as a BABBLE if MUSB is in HOST mode.
>>
>> Handle babble condition iff MUSB is in HOST mode.
>>
>> Signed-off-by: George Cherian <george.cherian@ti.com>
>> ---
>> drivers/usb/musb/musb_core.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
>> index 61da471..eff3c5c 100644
>> --- a/drivers/usb/musb/musb_core.c
>> +++ b/drivers/usb/musb/musb_core.c
>> @@ -849,7 +849,7 @@ b_host:
>> }
>>
>> /* handle babble condition */
>> - if (int_usb & MUSB_INTR_BABBLE)
>> + if (int_usb & MUSB_INTR_BABBLE && is_host_active(musb))
>> schedule_work(&musb->recover_work);
> I guess my following comments are for Daniel's patch as while which
> initially added the babble work.
>
> Should this if statement be merged into the previous 'if(int_usb &
> MUSB_INTR_RESET)' one, which handles the same interrupt and already
> handles host and device mode respectively.

Initially I too had the babble handling as part of 'if(int_usb &
MUSB_INTR_RESET)'
one. But during my tests I hit a corner case where in we hit a BABBLE
condition
on disconnect. In such case the babble interrupt can be handled only if
we have a seperate
check, else its considered as a BUS RESET.

When all devices are disconnected MUSB_DEVCTL_HM = 0 and the code
always enter the
else path. In this path it treats the BABBLE as a BUS RESET.

> Regards,
> -Bin.
>
>> #if 0
>> --
>> 1.8.3.1
>>
>> --
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--
-George



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