From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753263AbdJaN1m (ORCPT ); Tue, 31 Oct 2017 09:27:42 -0400 Received: from lelnx194.ext.ti.com ([198.47.27.80]:30154 "EHLO lelnx194.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751588AbdJaN1k (ORCPT ); Tue, 31 Oct 2017 09:27:40 -0400 Subject: Re: [PATCH] usb: dwc3: gadget: Fix .udc_set_speed() To: Felipe Balbi CC: , , , "# v4 . 13+" References: <1509454904-4966-1-git-send-email-rogerq@ti.com> <87a807cuvr.fsf@linux.intel.com> From: Roger Quadros Message-ID: Date: Tue, 31 Oct 2017 15:27:34 +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: <87a807cuvr.fsf@linux.intel.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-GB 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 Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id v9VDRkoP002846  Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki On 31/10/17 15:24, Felipe Balbi wrote: > Roger Quadros writes: > >> 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 or less than that >> supported by the dwc3 controller driver. >> >> Select the lesser of the 2 speeds so both are operating >> within limits. >> >> This fixes PHY Erratic errors and 2 second enumeration delay on >> TI's AM437x platforms. >> >> Fixes: 7d8d0639565f ("usb: dwc3: gadget: implement ->udc_set_speed()") >> Cc: # v4.13+ >> Reported-by: Dylan Howey >> Signed-off-by: Roger Quadros >> --- >> drivers/usb/dwc3/gadget.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c >> index f064f15..9f27ec0 100644 >> --- a/drivers/usb/dwc3/gadget.c >> +++ b/drivers/usb/dwc3/gadget.c >> @@ -2008,6 +2008,8 @@ static void dwc3_gadget_set_speed(struct usb_gadget *g, >> unsigned long flags; >> u32 reg; >> >> + speed = min(g->max_speed, speed); > > should we do that in udc core itself? > > @@ -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); > + } > } > > /** > > then the fix applies for all UDCs. > Sounds like a good idea. Will re-spin this patch. -- cheers, -roger Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki