RE: USB driver issue

Dasgupta, Romit
2008-07-30T12:59:14Z

What is the application you are using and could you turn the musb driver debug options? You can try it by

echo "D 3" > /proc/driver/musb_hdrc (Check if MUSB_DEBUG is enabled).

This should give more helpful messages.

>-----Original Message-----
>From: linux-omap-open-source-bounces@linux.omap.com [mailto:linux-omap-open-
>source-bounces@linux.omap.com] On Behalf Of SUBHRANIL CHOUDHURY
>Sent: Wednesday, July 30, 2008 5:50 PM
>To: Gadiyar, Anand
>Cc: linux-omap-open-source@linux.omap.com
>Subject: Re: USB driver issue
>
>hi,
>I am using Mistral OMAP3430 OSK2.1 board. It is the USB OTG port.
>The Philips tranciever ISP1504.
>I am enabling the EHCI and OHCI in the kernel menuconfig.
>
>This was the error print i was getting:
>
>Unable to handle kernel NULL pointer dereference at virtual address 00000000
>pgd = c54d8000
>[00000000] *pgd=81401031, *pte=00000000, *ppte=00000000
>Internal error: Oops: 817 [#1]
>Modules linked in:
>CPU: 0 Not tainted (2.6.22.18-omap3 #29)
>PC is at consistent_sync+0x40/0xa4
>LR is at usb_hcd_submit_urb+0x7b0/0x8b4
>pc : [<c00315ac>] lr : [<c02307e0>] psr: 20000013
>sp : c1403c48 ip : c1403c58 fp : c1403c54
>r10: ffff8003 r9 : 00000020 r8 : 00000020
>r7 : c483dc20 r6 : c0569000 r5 : c23c040c r4 : ff2d2000
>r3 : 00000000 r2 : 00000002 r1 : ff2dba38 r0 : ff2d2000
>Flags: nzCv IRQs on FIQs on Mode SVC_32 Segment user
>Control: 00c5387f Table: 854d8018 DAC: 00000015
>
>Do you get some clue from this about what is happening?
>
>
>
>
>On Wed, Jul 30, 2008 at 5:35 PM, Gadiyar, Anand <gadiyar@ti.com> wrote:
>
>> > Hi all,
>> > I am trying to validate the USB driver on OMAP3430 with the
>> > 2.6.22.18kernel. I am facing problems in the process while trying to
>> > do a USB transfer with DMA enabled.
>> > The apllication is breaking in a function called
>> > consistent_sync. The error message is like "Unable to handle kernel Null
>> pointer".
>>
>> Which board are you using? Which is the USB port - EHCI/OHCI/OTG?
>>
>> Assuming it is the USB OTG port (because that is the only one where you
>> can enable or disable DMA), what is the transceiver being used on the port?
>>
>>
>> > The issue is same with both OHCI and EHCI controller. And the
>> > issue is not coming if i disable DMA.
>>
>> I don't think you have control over DMA disabling with the OHCI/EHCI
>> controller. Are you sure you are using the OHCI/EHCI controller?
>>
>> The "Unable to handle kernel Null pointer" message comes with some more
>> data.
>> We won't be able to help you out without the rest of the log, but the
>> answers to
>> questions above are essential before we move on to this.
>>
>> >
>> > Has anyone tried USB packet transfer with DMA enabled? Please
>> > let me know.
>> >
>> > Regards,
>> > Subhro
>>
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