Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936373AbcJ1Jbk (ORCPT ); Fri, 28 Oct 2016 05:31:40 -0400 Received: from mail-wm0-f44.google.com ([74.125.82.44]:38234 "EHLO mail-wm0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752046AbcJ1Jbi (ORCPT ); Fri, 28 Oct 2016 05:31:38 -0400 Subject: Re: [PATCH v2 0/3] usb: musb: da8xx: Fix few issues To: David Lechner , 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: Alexandre Bailon Message-ID: Date: Fri, 28 Oct 2016 11:31:35 +0200 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: <245c574f-912a-9997-094e-069211dd2c2e@lechnology.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2730 Lines: 65 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. >> >> 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. >> >> --- >> >> 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 I have the same issue except the disconnect is called when I use the OTG mode.