From nobody Mon Apr 13 14:10:42 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4A489C4332F for ; Mon, 5 Dec 2022 20:15:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233182AbiLEUPv (ORCPT ); Mon, 5 Dec 2022 15:15:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55906 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232688AbiLEUPr (ORCPT ); Mon, 5 Dec 2022 15:15:47 -0500 Received: from mailfilter05-out40.webhostingserver.nl (mailfilter05-out40.webhostingserver.nl [195.211.74.36]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8CBE027FCF for ; Mon, 5 Dec 2022 12:15:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=exalondelft.nl; s=whs1; h=content-transfer-encoding:mime-version:references:in-reply-to:message-id:date: subject:cc:to:from:from; bh=dr7UwJp1aWEnCa4twHC7nPXuky/8LKPXZIlvLw50gwY=; b=FiilAHVFYovMsp/DEEMDbX1gG3gpcz315Q+nUTOTDXIpWcAtxGcD8sZLL9ktJL4PIRCsErdW7wg3g XHkTxxmyHesDqCOW1RY435eaIdzPyrbjZ82N2dIRJ9xukVQFf2X78WN9HG1denjgG27VBTQA/xzze8 W1Put4fi07ZFyhsMChyyIEgy/dNqFKalQ5Rd2FGXs47/+NtY/wypFUalv0719UFnWxmPzTGC5mlsIU c8WiWhFZbyIWoI/Izi9qpejhBBJ3QLUKW7ROanWuvv3eZC26eiKhBH/fzet+u+V+69WWLpJkGfL0tY vEIPbfGrQSXT4FPGd+3NclRd62C5szQ== X-Halon-ID: 985df67c-74d9-11ed-9686-001a4a4cb933 Received: from s198.webhostingserver.nl (s198.webhostingserver.nl [141.138.168.154]) by mailfilter05.webhostingserver.nl (Halon) with ESMTPSA id 985df67c-74d9-11ed-9686-001a4a4cb933; Mon, 05 Dec 2022 21:15:43 +0100 (CET) Received: from 2a02-a466-68ed-1-f633-1bb8-92a6-ba5d.fixed6.kpn.net ([2a02:a466:68ed:1:f633:1bb8:92a6:ba5d] helo=delfion.fritz.box) by s198.webhostingserver.nl with esmtpa (Exim 4.96) (envelope-from ) id 1p2HsM-001b54-2t; Mon, 05 Dec 2022 21:15:42 +0100 From: Ferry Toth To: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Heikki Krogerus , Greg Kroah-Hartman , Thinh Nguyen , Sean Anderson , Liu Shixin , Ferry Toth , Andrey Smirnov , Andy Shevchenko , Ferry Toth , stable@vger.kernel.org Subject: [PATCH v5 1/2] usb: ulpi: defer ulpi_register on ulpi_read_id timeout Date: Mon, 5 Dec 2022 21:15:26 +0100 Message-Id: <20221205201527.13525-2-ftoth@exalondelft.nl> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20221205201527.13525-1-ftoth@exalondelft.nl> References: <20221205201527.13525-1-ftoth@exalondelft.nl> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Antivirus-Scanner: Clean mail though you should still use an Antivirus Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Since commit 0f0101719138 ("usb: dwc3: Don't switch OTG -> peripheral if extcon is present") Dual Role support on Intel Merrifield platform broke due to rearranging the call to dwc3_get_extcon(). It appears to be caused by ulpi_read_id() on the first test write failing with -ETIMEDOUT. Currently ulpi_read_id() expects to discover the phy via DT when the test write fails and returns 0 in that case, even if DT does not provide the phy. As a result usb probe completes without phy. Make ulpi_read_id() return -ETIMEDOUT to its user if the first test write fails. The user should then handle it appropriately. A follow up patch will make dwc3_core_init() set -EPROBE_DEFER in this case and bail out. Fixes: ef6a7bcfb01c ("usb: ulpi: Support device discovery via DT") Cc: stable@vger.kernel.org Signed-off-by: Ferry Toth Acked-by: Heikki Krogerus --- drivers/usb/common/ulpi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/common/ulpi.c b/drivers/usb/common/ulpi.c index d7c8461976ce..60e8174686a1 100644 --- a/drivers/usb/common/ulpi.c +++ b/drivers/usb/common/ulpi.c @@ -207,7 +207,7 @@ static int ulpi_read_id(struct ulpi *ulpi) /* Test the interface */ ret =3D ulpi_write(ulpi, ULPI_SCRATCH, 0xaa); if (ret < 0) - goto err; + return ret; =20 ret =3D ulpi_read(ulpi, ULPI_SCRATCH); if (ret < 0) --=20 2.37.2 From nobody Mon Apr 13 14:10:42 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 84182C4321E for ; Mon, 5 Dec 2022 20:16:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232688AbiLEUQD (ORCPT ); Mon, 5 Dec 2022 15:16:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55980 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233250AbiLEUP5 (ORCPT ); Mon, 5 Dec 2022 15:15:57 -0500 Received: from mailfilter02-out40.webhostingserver.nl (mailfilter02-out40.webhostingserver.nl [195.211.72.22]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B965A28725 for ; Mon, 5 Dec 2022 12:15:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=exalondelft.nl; s=whs1; h=content-transfer-encoding:mime-version:references:in-reply-to:message-id:date: subject:cc:to:from:from; bh=AL68zLQaEqSRdRgznjgITv4ps8SL1cEIOEoowj++pC0=; b=LdS12PfvgO5v8km82BezuW5J7/N+8R0QJmVHg5WCv4c2rBVONAILw2o5N2+KXgYO91Zy0658TRUPf o8lpPyIMVCTlQe5ipASaefd3/OsYLGbhrvKQ8g3e+xtusdTdgrwBZilus7V2RkwbgPLhNF1V1Tlc0Z VS/3AT8MmDjNPk9ZfG4vyVS9VCF2K6futTKdwrkRfeXN/WpzXr55i6yaKmaMfgMrOiNOyfN2vkpaQ0 wNtEah/xcTLXS0v28pHx1ZATXIeYXDSsFjdKg40jkO7SmBKqpbMC3HIPbbN/hGl8pW9xyB/r0wqcMW CVGeBWDep4K/pm9cCKIIhUumeLXMMmw== X-Halon-ID: 9e8bd91a-74d9-11ed-aeca-001a4a4cb922 Received: from s198.webhostingserver.nl (s198.webhostingserver.nl [141.138.168.154]) by mailfilter02.webhostingserver.nl (Halon) with ESMTPSA id 9e8bd91a-74d9-11ed-aeca-001a4a4cb922; Mon, 05 Dec 2022 21:15:53 +0100 (CET) Received: from 2a02-a466-68ed-1-f633-1bb8-92a6-ba5d.fixed6.kpn.net ([2a02:a466:68ed:1:f633:1bb8:92a6:ba5d] helo=delfion.fritz.box) by s198.webhostingserver.nl with esmtpa (Exim 4.96) (envelope-from ) id 1p2HsX-001b54-0z; Mon, 05 Dec 2022 21:15:53 +0100 From: Ferry Toth To: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Heikki Krogerus , Greg Kroah-Hartman , Thinh Nguyen , Sean Anderson , Liu Shixin , Ferry Toth , Andrey Smirnov , Andy Shevchenko , Ferry Toth , stable@vger.kernel.org Subject: [PATCH v5 2/2] usb: dwc3: core: defer probe on ulpi_read_id timeout Date: Mon, 5 Dec 2022 21:15:27 +0100 Message-Id: <20221205201527.13525-3-ftoth@exalondelft.nl> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20221205201527.13525-1-ftoth@exalondelft.nl> References: <20221205201527.13525-1-ftoth@exalondelft.nl> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Antivirus-Scanner: Clean mail though you should still use an Antivirus Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Since commit 0f0101719138 ("usb: dwc3: Don't switch OTG -> peripheral if extcon is present"), Dual Role support on Intel Merrifield platform broke due to rearranging the call to dwc3_get_extcon(). It appears to be caused by ulpi_read_id() masking the timeout on the first test write. In the past dwc3 probe continued by calling dwc3_core_soft_rese= t() followed by dwc3_get_extcon() which happend to return -EPROBE_DEFER. On deferred probe ulpi_read_id() finally succeeded. Due to above mentioned rearranging -EPROBE_DEFER is not returned and probe completes without phy. On Intel Merrifield the timeout on the first test write issue is reproducib= le but it is difficult to find the root cause. Using a mainline kernel and rootfs with buildroot ulpi_read_id() succeeds. As soon as adding ftrace / bootconfig to find out why, ulpi_read_id() fails and we can't analyze the flow. Using another rootfs ulpi_read_id() fails even without adding ftrace. We suspect the issue is some kind of timing / race, but merely retrying ulpi_read_id() does not resolve the issue. As we now changed ulpi_read_id() to return -ETIMEDOUT in this case, we need to handle the error by calling dwc3_core_soft_reset() and request -EPROBE_DEFER. On deferred probe ulpi_read_id() is retried and succeeds. Fixes: ef6a7bcfb01c ("usb: ulpi: Support device discovery via DT") Cc: stable@vger.kernel.org Signed-off-by: Ferry Toth Acked-by: Thinh Nguyen --- drivers/usb/dwc3/core.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index 648f1c570021..2779f17bffaf 100644 --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -1106,8 +1106,13 @@ static int dwc3_core_init(struct dwc3 *dwc) =20 if (!dwc->ulpi_ready) { ret =3D dwc3_core_ulpi_init(dwc); - if (ret) + if (ret) { + if (ret =3D=3D -ETIMEDOUT) { + dwc3_core_soft_reset(dwc); + ret =3D -EPROBE_DEFER; + } goto err0; + } dwc->ulpi_ready =3D true; } =20 --=20 2.37.2