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).
Fix this. Fixes: 7e91f6ccdc84 ("usb: Add Cadence USB3 host and gadget driver") Signed-off-by: Siddharth Vadapalli <s-vadapa...@ti.com> --- Hello, This patch is based on commit dd4d130c8e clk: renesas: rcar-gen3: Fix SSCG caching replacement with MDSEL/PE caching of the master branch of U-Boot. v1: https://patchwork.ozlabs.org/project/uboot/patch/20241007104239.1624430-1-s-vadapa...@ti.com/ Changes since v1: - Based on Roger's feedback at: https://patchwork.ozlabs.org/project/uboot/patch/20241007104239.1624430-1-s-vadapa...@ti.com/#3389960 rather than using usb_ep_set_maxpacket_limit() which changes "maxpacket_limit" in addition to "maxpacket", only update the "maxpacket" member of usb_ep. Regards, Siddharth. drivers/usb/cdns3/gadget.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c index ac7e469469..a30c40ef80 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(). + */ + priv_ep->endpoint.maxpacket = max_packet_size; + ret = cdns3_ep_onchip_buffer_reserve(priv_dev, buffering + 1, !!priv_ep->dir); if (ret) { -- 2.40.1