On 24-09-23 16:12:02, Xu Yang wrote: > To let the device controller work properly on short packet limitations, > one usb request should only correspond to one dTD. Then every dTD will > set IOC. In theory, each dTD support up to 20KB data transfer if the > offset is 0. Due to we cannot predetermine the offset, this will limit > the usb request length to max 16KB. This should be fine since most of > the user transfer data based on this size policy. > > Signed-off-by: Xu Yang <xu.yang_2@xxxxxxx> Acked-by: Peter Chen <peter.chen@xxxxxxxxxx> > > --- > Changes in v2: > - limit request length only when ci->has_short_pkt_limit set > - modify commit message > --- > drivers/usb/chipidea/ci.h | 1 + > drivers/usb/chipidea/udc.c | 6 ++++++ > 2 files changed, 7 insertions(+) > > diff --git a/drivers/usb/chipidea/ci.h b/drivers/usb/chipidea/ci.h > index e4b003d060c2..97437de52ef6 100644 > --- a/drivers/usb/chipidea/ci.h > +++ b/drivers/usb/chipidea/ci.h > @@ -25,6 +25,7 @@ > #define TD_PAGE_COUNT 5 > #define CI_HDRC_PAGE_SIZE 4096ul /* page size for TD's */ > #define ENDPT_MAX 32 > +#define CI_MAX_REQ_SIZE (4 * CI_HDRC_PAGE_SIZE) > #define CI_MAX_BUF_SIZE (TD_PAGE_COUNT * CI_HDRC_PAGE_SIZE) > > /****************************************************************************** > diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c > index 18c1882cf088..5badb39cb2bf 100644 > --- a/drivers/usb/chipidea/udc.c > +++ b/drivers/usb/chipidea/udc.c > @@ -972,6 +972,12 @@ static int _ep_queue(struct usb_ep *ep, struct usb_request *req, > return -EMSGSIZE; > } > > + if (ci->has_short_pkt_limit && > + hwreq->req.length > CI_MAX_REQ_SIZE) { > + dev_err(hwep->ci->dev, "request length too big (max 16KB)\n"); > + return -EMSGSIZE; > + } > + > /* first nuke then test link, e.g. previous status has not sent */ > if (!list_empty(&hwreq->queue)) { > dev_err(hwep->ci->dev, "request already in queue\n"); > -- > 2.34.1 >