From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752191AbdJaNyl (ORCPT ); Tue, 31 Oct 2017 09:54:41 -0400 Received: from lelnx193.ext.ti.com ([198.47.27.77]:49713 "EHLO lelnx193.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751050AbdJaNyj (ORCPT ); Tue, 31 Oct 2017 09:54:39 -0400 Subject: Re: [PATCH v2] usb: dwc3: gadget: Fix .udc_set_speed() To: CC: , , , "# v4 . 13+" References: <1509454904-4966-1-git-send-email-rogerq@ti.com> <3773d6f2-113b-862e-3365-d47efa3a77ed@ti.com> From: Roger Quadros Message-ID: <832a42bb-aaa3-68a3-72f9-1938e48a484a@ti.com> Date: Tue, 31 Oct 2017 15:54:34 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: <3773d6f2-113b-862e-3365-d47efa3a77ed@ti.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-GB Content-Transfer-Encoding: 7bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Felipe, Forgot to update subject :P. Will resend. On 31/10/17 15:47, Roger Quadros wrote: > Currently UDC core calls ->udc_set_speed() with the speed parameter > containing the maximum speed supported by the gadget function > driver. This might very well be more than that supported by the > UDC controller driver. > > Select the lesser of the 2 speeds so both UDC and gadget function > driver are operating within limits. > > This fixes PHY Erratic errors and 2 second enumeration delay on > TI's AM437x platforms. > > Fixes: 6099eca796ae ("usb: gadget: core: introduce ->udc_set_speed() method") > Cc: # v4.13+ > Reported-by: Dylan Howey > Signed-off-by: Roger Quadros > --- > v2: > - Move speed limiting code to UDC core. > > drivers/usb/gadget/udc/core.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c > index d41d07a..def1b05 100644 > --- a/drivers/usb/gadget/udc/core.c > +++ b/drivers/usb/gadget/udc/core.c > @@ -1080,8 +1080,12 @@ static inline void usb_gadget_udc_stop(struct usb_udc *udc) > static inline void usb_gadget_udc_set_speed(struct usb_udc *udc, > enum usb_device_speed speed) > { > - if (udc->gadget->ops->udc_set_speed) > - udc->gadget->ops->udc_set_speed(udc->gadget, speed); > + if (udc->gadget->ops->udc_set_speed) { > + enum usb_device_speed s; > + > + s = min(speed, udc->gadget->max_speed); > + udc->gadget->ops->udc_set_speed(udc->gadget, s); > + } > } > > /** > -- cheers, -roger Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki