On Wed, Jul 20, 2011 at 11:15 AM, Pandita, Vikram <[email protected]> wrote: > On Tue, Jul 19, 2011 at 10:34 PM, Jassi Brar <[email protected]> wrote: >> >> On Wed, Jul 20, 2011 at 10:41 AM, Vikram Pandita <[email protected]> >> wrote: >> > From: Anand Gadiyar <[email protected]> >> > >> > This patch enables the DMA mode1 RX support. >> > This feature is enabled based on the short_not_ok flag passed from >> > gadget drivers. >> > >> > This will result in a thruput performance gain of around >> > 40% for USB mass-storage/mtp use cases. >> > >> > Signed-off-by: Anand Gadiyar <[email protected]> >> > Signed-off-by: Moiz Sonasath <[email protected]> >> > Signed-off-by: Vikram Pandita <[email protected]> >> > Tested-by: Vikram Pandita <[email protected]> >> > --- >> > v1 - initial push >> > v2 - fixed whitespace issues as per Sergei Shtylyov<[email protected]> >> > comments >> > v3 - restor authorship to Anand Gadiyar <[email protected]> >> > v4 - adding my signed-off as per Kevin Hilman <[email protected]> >> > >> > drivers/usb/musb/musb_gadget.c | 68 >> > ++++++++++++++++++++++++--------------- >> > 1 files changed, 42 insertions(+), 26 deletions(-) >> >> > @@ -683,6 +684,18 @@ static void rxstate(struct musb *musb, struct >> > musb_request *req) >> > >> > if (csr & MUSB_RXCSR_RXPKTRDY) { >> > len = musb_readw(epio, MUSB_RXCOUNT); >> > + >> > + /* >> > + * Enable Mode 1 for RX transfers only for mass-storage >> > + * use-case, based on short_not_ok flag which is set only >> > + * from file_storage and f_mass_storage drivers >> > + */ >> > + >> > + if (request->short_not_ok && len == musb_ep->packet_sz) >> > + use_mode_1 = 1; >> > + else >> > + use_mode_1 = 0; >> > + >> There is nothing UMS class specific in this patch... >> (request->short_not_ok && len == musb_ep->packet_sz) may not be the >> signature of, and only of, Mass Storage Functions. So maybe removing >> the UMS mention from >> comment and change-log is a good idea. > > Have you grepped the code in drivers/usb/gadget/*.* > only UMS sets this flag today and hence the use of this flag. > > As i understand, on UMS, CSW/data/CBW - the data part size is a known > size and to be safe that mode=1 dma is not stuck up, > the mode is enabled only for the gadget driver that sets short_not_ok > flag - and that today happens to be only UMS.
This *today happens to be only UMS* is my exact point here. Can you guarantee no other function driver will ever expect only full packet xfers and treat short as errors ? >> You might want to add is-ep-type-bulk-out check to the condition >> though, so that it doesn't affect >> cases that you didn't verify. > > TX path (IN host), already uses the mode=1 DMA and hence the comment > is not valid. > This patch just also enables mode=1 on RX path. Well, then no need for the ep-type check. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
