From: Ben Dooks Date: Mon, 19 Jul 2010 08:40:45 +0000 (+0100) Subject: USB: s3c-hsotg: Only load packet per fifo write X-Git-Tag: firefly_0821_release~9833^2~1028^2~35 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=03e10e5ab5ba6511ddaf80085cf08c62e9336fa5;p=firefly-linux-kernel-4.4.55.git USB: s3c-hsotg: Only load packet per fifo write Limit the IN FIFO write to a single packet per attempt at writing, as per the specifications and ensure that we don't return fifo-full so that we can continue writing packets if we have the space. Signed-off-by: Ben Dooks Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/gadget/s3c-hsotg.c b/drivers/usb/gadget/s3c-hsotg.c index 4196e376a346..df6a39d6270f 100644 --- a/drivers/usb/gadget/s3c-hsotg.c +++ b/drivers/usb/gadget/s3c-hsotg.c @@ -538,6 +538,17 @@ static int s3c_hsotg_write_fifo(struct s3c_hsotg *hsotg, if (can_write > 512) can_write = 512; + /* limit the write to one max-packet size worth of data, but allow + * the transfer to return that it did not run out of fifo space + * doing it. */ + if (to_write > hs_ep->ep.maxpacket) { + to_write = hs_ep->ep.maxpacket; + + s3c_hsotg_en_gsint(hsotg, + periodic ? S3C_GINTSTS_PTxFEmp : + S3C_GINTSTS_NPTxFEmp); + } + /* see if we can write data */ if (to_write > can_write) {