On Mon, Oct 07, 2024 at 03:02:34PM +0300, Roger Quadros wrote: Hello Roger,
> On 07/10/2024 13:42, Siddharth Vadapalli wrote: > > The function cdns3_ep_config() calculates the maximum packet size based > > on the Endpoint Type and the Gadget Speed and stores it in the variable > > "max_packet_size". This value is then programmed in the USB Controller > > for the corresponding Endpoint. This may result in a mismatch between > > the maximum packet size programmed in the USB controller and the maximum > > packet size seen by the UDC Core via "maxpacket" member of "struct usb_ep". > > Additionally, since TD_SIZE is calculated in cdns3_ep_run_transfer() on the > > basis of the maximum packet size stored in the "maxpacket" member of > > "struct usb_ep", it may lead to an incorrect value of TD_SIZE when compared > > with what the USB controller actually expects (max_packet_size). > > [...] > > diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c > > index ac7e469469..b0b08768d9 100644 > > --- a/drivers/usb/cdns3/gadget.c > > +++ b/drivers/usb/cdns3/gadget.c > > @@ -1637,6 +1637,14 @@ void cdns3_ep_config(struct cdns3_endpoint *priv_ep) > > else > > priv_ep->trb_burst_size = 16; > > > > + /* > > + * The Endpoint is configured to handle a maximum packet size of > > + * max_packet_size. Hence, set priv_ep->endpoint.maxpacket to > > + * max_packet_size. This is necessary to ensure that the TD_SIZE > > + * is calculated correctly in cdns3_ep_run_transfer(). > > + */ > > + usb_ep_set_maxpacket_limit(&priv_ep->endpoint, max_packet_size); > > + > > from include/linux/usb/gadget.h > > * struct usb_ep - device side representation of USB endpoint > ... > * @maxpacket:The maximum packet size used on this endpoint. The initial > * value can sometimes be reduced (hardware allowing), according to > * the endpoint descriptor used to configure the endpoint. > * @maxpacket_limit:The maximum packet size value which can be handled by this > * endpoint. It's set once by UDC driver when endpoint is initialized, > and > * should not be changed. Should not be confused with maxpacket. > > What you want to change is ep->maxpacket and not ep->maxpacket_limit as that > is > fixed for a particular UDC. > > how about? > priv-ep->endpoint.maxpacket = max_packet_size; Yes, this is accurate. I will post the v2 patch with this change. Thank you for reviewing the patch. Regards, Siddharth.
