On Wed, Mar 20, 2013 at 11:26:49PM +0100, Michael Grzeschik wrote: > Each TD can maintain five buffer pointers. Each of them is 4k aligned. > There is no need to limit this to less then possible. This patch lowers > the overhead of extra TDs. > > Signed-off-by: Michael Grzeschik <[email protected]> > --- > drivers/usb/chipidea/udc.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c > index 70296c7..007a97a 100644 > --- a/drivers/usb/chipidea/udc.c > +++ b/drivers/usb/chipidea/udc.c > @@ -693,8 +693,8 @@ static int _ep_queue(struct usb_ep *ep, struct > usb_request *req, > goto done; > } > > - if (req->length > 4 * CI13XXX_PAGE_SIZE) { > - req->length = 4 * CI13XXX_PAGE_SIZE; > + if (req->length > 5 * CI13XXX_PAGE_SIZE) { > + req->length = 5 * CI13XXX_PAGE_SIZE; > retval = -EMSGSIZE; > dev_warn(mEp->ci->dev, "request length truncated\n"); > } > -- > 1.8.2.rc2
>From the discussion with Peter, this patch is wrong. We have to keep that limit to 4 in the special case when (req->dma % PAGE_COUNT). Michael -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
