On Tue, Nov 25, 2014 at 01:56:38AM +0100, Ricardo Ribalda Delgado wrote:
> Hello
> 
> I cannot make work the parameter use_dma_chaining with g_mass_storage
> and a usb3380 device. The initial enumeration works, but after a
> couple of frames the enumeration is restarted. If I compare usbmon
> with and without the parameter I can see that the device fails to
> reply to the host.
> 
>  While going through the code I realized that there is only on scathe
> gather descriptor per endpoint and I wonder how can you make work a
> dma_chain with only one descriptor!.
> 
>  I think the driver is expecting a special pattern of execution or
> maybe (probably) I am not understanding the code right.
> 
>   Can somebody confirm that this parameter works on a net2280, and if
> not, can I remove the obsolete code, so no other person loses some
> hours and gray hair :) ?

might be better if you can fix the code, instead. We have a "better"
scatter-gather support in the framework itself.

UDC needs to set gadget->sg_supported and a pointer to the sg should be
passed in by the gadget driver through usb_request->sg.

cheers

-- 
balbi

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