Hi, On 27/06/2023 15:56, Ravi Gunasekaran wrote: > Hi, > > Firstly, I'm not sure if it is alright to post queries this way. > If it is wrong, I apologize for it. Please let me know the right path/forum to ask the questions. > > This is regarding the commit > dce49449e04f usb: cdns3: allocate TX FIFO size according to composite EP number > > This commit introduced cdns3_gadget_check_config() which is invoked while binding gadget created via configfs and > also a logic to calculate ep_buf_size (which was CDNS3_EP_BUF_SIZE = 4). > > But for gadgets such as g_ether, g_cdc, the checks are not performed. And also for these legacy gadget drivers, > memory needs to be reserved for multiple IN end points and shared memory for OUT end points. So when ep_buf_size = 15, > the memory reservation fails, as it exceeds total onchip memory. > > So I was wondering if additional checks need to done in the cadence gadget driver or am I doing something wrong while > loading gadgets such as g_ether. > I think Ravi's concern is that. prior to commit dce49449e04f, priv_dev->ep_buf_size was fixed at 4. After commit dce49449e04f, it is at 0 if check_config() is not called e.g. in the legacy gadget cases (e.g. g_ether). So cdns3_ep_config() fails with dev_err(priv_dev->dev, "onchip mem is full, ep is invalid\n"). A potential fix might be to start with priv_dev->ep_buf_size = 4 instead of 0 so it works for legacy gadgets as well where check_config() is not invoked. -- cheers, -roger
