From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S942666AbcJ0SpA (ORCPT ); Thu, 27 Oct 2016 14:45:00 -0400 Received: from vern.gendns.com ([206.190.152.46]:53502 "EHLO vern.gendns.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934164AbcJ0So4 (ORCPT ); Thu, 27 Oct 2016 14:44:56 -0400 Subject: Re: [PATCH v2 0/3] usb: musb: da8xx: Fix few issues To: Alexandre Bailon , khilman@baylibre.com, b-liu@ti.com, balbi@kernel.org References: <1477479503-5131-1-git-send-email-abailon@baylibre.com> <2220c0c3-de72-4d3e-f438-56cb6e9cac15@lechnology.com> Cc: linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org From: David Lechner Message-ID: <245c574f-912a-9997-094e-069211dd2c2e@lechnology.com> Date: Thu, 27 Oct 2016 13:44:52 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.3.0 MIME-Version: 1.0 In-Reply-To: <2220c0c3-de72-4d3e-f438-56cb6e9cac15@lechnology.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - vern.gendns.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - lechnology.com X-Get-Message-Sender-Via: vern.gendns.com: authenticated_id: davidmain+lechnology.com/only user confirmed/virtual account not confirmed X-Authenticated-Sender: vern.gendns.com: davidmain@lechnology.com X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/27/2016 12:16 PM, David Lechner wrote: > On 10/26/2016 05:58 AM, Alexandre Bailon wrote: >> Currently, the USB OTG of the da8xx doesn't work. >> This series intend to fix them. >> >> Change in v2: >> * Fix the error path da8xx_musb_init() >> >> Alexandre Bailon (3): >> usb: musb: da8xx: Call earlier clk_prepare_enable() >> phy: da8xx-usb: Configure CFGCHIP2 to support OTG workaround >> usb: musb: da8xx: Only execute the OTG workaround when phy in OTG mode >> >> drivers/phy/phy-da8xx-usb.c | 17 ++++++++++++----- >> drivers/usb/musb/da8xx.c | 28 +++++++++++++++++++--------- >> 2 files changed, 31 insertions(+), 14 deletions(-) >> > > I have found another problem with peripheral mode. When we force > peripheral mode, the glue layer currently uses CFGCHIP2 to override the > VBUS and ID. This causes it to not be able to detect disconnection > because the VBUS is overridden. > > Here is a patch to fix the problem. I have tested this on LEGO > MINDSTORMS EV3 (AM1808). This works because the ID pin is internally > pulled up on the SoC, so we don't need to override it. > > --- > > diff --git a/drivers/usb/musb/da8xx.c b/drivers/usb/musb/da8xx.c > index 2bc12a2..33daa3b 100644 > --- a/drivers/usb/musb/da8xx.c > +++ b/drivers/usb/musb/da8xx.c > @@ -374,9 +374,7 @@ static int da8xx_musb_set_mode(struct musb *musb, u8 > musb_mode) > case MUSB_HOST: /* Force VBUS valid, ID = 0 */ > phy_mode = PHY_MODE_USB_HOST; > break; > - case MUSB_PERIPHERAL: /* Force VBUS valid, ID = 1 */ > - phy_mode = PHY_MODE_USB_DEVICE; > - break; > + case MUSB_PERIPHERAL: > case MUSB_OTG: /* Don't override the VBUS/ID > comparators */ > phy_mode = PHY_MODE_USB_OTG; > break; > > --- > > If this works for other SoCs/boards, I think we should make this change. > If it doesn't work, we could work around the VBUS problem by polling > VBUSSENSE in CFGCHIP2. But, I like the simple solution above better. I have realized that due to the way my device is wired, I can actually use OTG mode and it will behave exactly as peripheral mode because the ID pin is not connected. So, maybe this patch is not needed after all.