Re: [PATCH 03/03] omap hsmmc: adaptation of sdma descriptor autoloading feature

Venkatraman S
2010-03-12T08:18:12Z

Tony Lindgren wrote:
> * Venkatraman S <svenkatr@ti.com> [100311 07:04]:
>> Tony Lindgren wrote:
>> >
>> > Does the driver still work in PIO mode?
>> >
>> > We need to have the drivers capable to fail over to PIO mode
>> > as the DMA channels can run out.
>> >
>>
>>    The driver doesn't have an automatic fallback to PIO,
>> even without my patch. A error return from omap_request_dma is
>> propogated all the way back to the transfer request.
>>   The decision to use_dma (the variable) is unaltered.
>
> OK, that might explain some nasty surprises then..
>
> With these patches, does the driver still work in PIO mode though?

No. The workhorse code to actually push the data byte by byte
is not present in the hsmmc driver.