Re: videobuf2-vmalloc suspect for corrupted data

[Hans Verkuil <hverkuil@xs4all.nl>]

On 04/07/2014 12:49 PM, Divneil Wadhawan wrote:
> Hi Pawel,
> 
> Thanks for the quick response.
> 
>> Is it possible that your userspace is not always queuing the same
>> userptr memory areas with the same v4l2_buffer index values?
> No, userptr is always consistent with the index.
> In fact, when we dump the captured buffer (Transport Stream) in this case, kernel space data and user-space are different.
> When that TS is played, macroblocks are observed from user-space and not from the kernel space dump.
> Although, user-space bad data is random, but, I have never seen kernel space dumped TS as bad.
> 
>> In other words, if you have 2 buffers in use, under userspace mapping
>> at addr1 and addr2, if you queue addr1 with index=0 and addr2 with
>> index=1 initially,
>> you should always keep queuing addr1 with index=0 and never 1, etc.
> Yeah! this is the same rule which is being followed.
> 
>> Also, what architecture are you running this on?
> ARM Cortex A9 SMP

Two more questions:

Which kernel version are you using?

Which capture driver are you using?

Regards,

	Hans