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).

Fix this by using usb_ep_set_maxpacket_limit().

Fixes: 7e91f6ccdc84 ("usb: Add Cadence USB3 host and gadget driver") Signed-off-by: Siddharth Vadapalli s-vadapalli@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.

Patch has been tested on AM642-EVM.

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..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;

ret = cdns3_ep_onchip_buffer_reserve(priv_dev, buffering + 1, !!priv_ep->dir); if (ret) {