From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1034232AbcJ1Rum (ORCPT ); Fri, 28 Oct 2016 13:50:42 -0400 Received: from vern.gendns.com ([206.190.152.46]:52877 "EHLO vern.gendns.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S942347AbcJ1Ruj (ORCPT ); Fri, 28 Oct 2016 13:50:39 -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> <245c574f-912a-9997-094e-069211dd2c2e@lechnology.com> Cc: linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org From: David Lechner Message-ID: Date: Fri, 28 Oct 2016 12:50:36 -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: 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 10/28/2016 04:31 AM, Alexandre Bailon wrote: > On 10/27/2016 08:44 PM, David Lechner wrote: >> 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. > How have you found it ? Does it cause any issues ? > I mean I had to enable traces to see that disconnect was not happening. I am also using the device tree patch series. I specified dr_mode = "peripheral" in my device tree because the device is only wired for use as a peripheral port. I have actually known about this issue for a long time. See and >>> >>> 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. > Actually, I'm wonder if that if not related to VBUS sensing. > May be we should set CFGCHIP2_VBDTCTEN in device mode. Yes, as we discussed in another thread, we should set CFGCHIP2_VBDTCTEN and CFGCHIP2_SESNDEN *always* regardless of mode. I still have the problem described above with these two enabled if and only if we are also setting CFGCHIP2_OTG_FORCE_PERIPHERAL. >>> >>> --- >>> >>> 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. >> > Actually, I'm sure that is related to ID The ID pin on my device is not connected, so I don't think this has to do with ID. It is always high (internally pulled up). > I have the same issue except the disconnect is called when I use the > OTG mode. > This is exactly the behavior I am seeing.