Hi, On Tue, Mar 22, 2011 at 10:42:08AM +0100, Mian Yousaf Kaukab wrote: > Hi, > > Thank you for applying the following patches. > > [PATCH 1/8] usb: musb: clear AUTOSET while clearing DMAENAB > [PATCH 6/8] usb: musb: ux500: copy dma mask from platform device to > musb device > > Please disregard the rest of the patchset. I will send the second > version (without above two patches) in a short while. > > On 03/22/2011 10:05 AM, Felipe Balbi wrote: > >On Tue, Mar 15, 2011 at 04:24:25PM +0100, Mian Yousaf Kaukab wrote: > >>For Inventra dma, dma is configured for rx transfers after receiving first > >>packet (MUSB_RXCSR_RXPKTRDY set in RXCSR). DMA is configured based on the > >>requested length or the maximum length dma can handle. However, if the > >>received packet is less than the maximum packet size, length of this packet > >>should be used to configure the dma. As it will be the only packet to transfer > >>for this request. > >> > >>Signed-off-by: Mian Yousaf Kaukab<mian.yousaf.kaukab@xxxxxxxxxxxxxx> > >AFAIK a short packet can't be transferred with mode1 DMA, so why even > >bother ? Or did you manage to get mode1 to transfer this short packet ? > > > > Without this patch, on the arrival of CBW rxstate() will pass > transfer_size = min(request->length - request->actual, channel->max_len); > to channel_program() when USE_MODE1 is set. So DMA will not know that > already a short packet has arrived. When channel_program() is called > with the > length of the short packet, DMA has the chance to reject the transfer. > > Part of the problem is that when g_mass_storage sends the request for CBW > it aligns the length to maxp even though it knows that CBW length is > expected. It > is done in set_bulk_out_req_length() in f_mass_storage.c. Not sure > why it is done. > If it is not needed, should I send a patch to fix that as well? I can't remember the details from the Mass Storage specification, but a patch to start a discussion with the authors wouldn't hurt ;-) -- balbi -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
