From patchwork Thu Jan 12 00:22:02 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Stultz X-Patchwork-Id: 91010 Delivered-To: patches@linaro.org Received: by 10.140.20.99 with SMTP id 90csp1381175qgi; Wed, 11 Jan 2017 16:22:11 -0800 (PST) X-Received: by 10.84.231.2 with SMTP id f2mr17277785plk.28.1484180531166; Wed, 11 Jan 2017 16:22:11 -0800 (PST) Return-Path: Received: from mail-pf0-x22d.google.com (mail-pf0-x22d.google.com. [2607:f8b0:400e:c00::22d]) by mx.google.com with ESMTPS id m5si7288424pgj.182.2017.01.11.16.22.11 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 11 Jan 2017 16:22:11 -0800 (PST) Received-SPF: pass (google.com: domain of john.stultz@linaro.org designates 2607:f8b0:400e:c00::22d as permitted sender) client-ip=2607:f8b0:400e:c00::22d; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org; spf=pass (google.com: domain of john.stultz@linaro.org designates 2607:f8b0:400e:c00::22d as permitted sender) smtp.mailfrom=john.stultz@linaro.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: by mail-pf0-x22d.google.com with SMTP id y143so2431578pfb.0 for ; Wed, 11 Jan 2017 16:22:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=IewvznMrB3ERhAfYs9BlHkz7dlWcAq5gcTRBL55Ss6k=; b=TCVElBhInnRNlm9IEnYZunTv3LS4XWwjr6uTuYqehBvynzMAt9fwe0Cl61eSNkpKYi 6OVrbe1dvimizEKveius1oKU4kquBICfRoxxfP7OYUyu1M7El1lOTaRkrBhNSj2AlK7e Z98Ebh6dev7ZEvKPYIFk50c83ApmpmebYt7aQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=IewvznMrB3ERhAfYs9BlHkz7dlWcAq5gcTRBL55Ss6k=; b=njyD36Ip9zUS0Dy39yJslPNfuwpQK3UCCWUXdBKW4LbEdQiojmhzQ5XSdhOcNd+kvq moqwD54NaPGFG9glIOcTlqUWQDzCfWgjvUWO2KY9AEBKcCz4eOli6+COxSwS6Bxh7Ptc 9Wa8zZJpA0Eqx13sWEF7td2drJoOpV4W+6nZ24jIlZuKmUnkjJEidpWD2GfVjzEe/0Cc KsgopPl7pWY+uZJjYSkbgkGMj3XVVOpy6WdDURs6j4XEjbD9zD8VCTT0nJS7AUnRuD8x F1lpkzPIIulskhCbXDRwSZSb8C1+RyA6SRPyzJBRlMkxz9t4xtoVmmyzdJGYjhhcoI9p PnoQ== X-Gm-Message-State: AIkVDXLLgqmsnoqg3ZH2LCSveO9ZJkK5Nfyrx/3fhxVaAQNDX7Ri1TnAC3zkBZORJznrdxbsUeY= X-Received: by 10.84.194.37 with SMTP id g34mr17111108pld.105.1484180530871; Wed, 11 Jan 2017 16:22:10 -0800 (PST) Return-Path: Received: from localhost.localdomain ([2601:1c2:1002:83f0:4e72:b9ff:fe99:466a]) by smtp.gmail.com with ESMTPSA id g85sm16364419pfe.38.2017.01.11.16.22.09 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 11 Jan 2017 16:22:10 -0800 (PST) From: John Stultz To: lkml Cc: John Stultz , Wei Xu , Guodong Xu , Amit Pundir , Rob Herring , John Youn , Douglas Anderson , Chen Yu , Vardan Mikayelyan , Kishon Vijay Abraham I , Felipe Balbi , Greg Kroah-Hartman , linux-usb@vger.kernel.org Subject: [PATCH 2/4 v3] usb: dwc2: Workaround case where GOTGCTL state is wrong Date: Wed, 11 Jan 2017 16:22:02 -0800 Message-Id: <1484180524-4087-3-git-send-email-john.stultz@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1484180524-4087-1-git-send-email-john.stultz@linaro.org> References: <1484180524-4087-1-git-send-email-john.stultz@linaro.org> When removing a USB-A to USB-otg adapter cable, we get a change status irq, and then in dwc2_conn_id_status_change, we erroniously see the GOTGCTL_CONID_B flag set. This causes us to get stuck in the "while (!dwc2_is_device_mode(hsotg))" loop, spitting out "Waiting for Peripheral Mode, Mode=Host" warnings until it fails out many seconds later. This patch works around the issue by re-reading the GOTGCTL state to check if the GOTGCTL_CONID_B is still set and if not restarting the change status logic. I suspect this isn't the best solution, but it seems to work well for me. Feedback would be greatly appreciated! Cc: Wei Xu Cc: Guodong Xu Cc: Amit Pundir Cc: Rob Herring Cc: John Youn Cc: Douglas Anderson Cc: Chen Yu Cc: Vardan Mikayelyan Cc: Kishon Vijay Abraham I Cc: Felipe Balbi Cc: Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org Acked-by: John Youn Reviewed-by: Vardan Mikayelyan Signed-off-by: John Stultz --- v2: Rework goto logic suggested by Vardan, and add a comment v3: * Rebased to synopsys-usb/next branch --- drivers/usb/dwc2/hcd.c | 9 +++++++++ 1 file changed, 9 insertions(+) -- 2.7.4 diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c index b63b14f..888923c 100644 --- a/drivers/usb/dwc2/hcd.c +++ b/drivers/usb/dwc2/hcd.c @@ -3238,6 +3238,14 @@ static void dwc2_conn_id_status_change(struct work_struct *work) dwc2_is_host_mode(hsotg) ? "Host" : "Peripheral"); usleep_range(20000, 40000); + /* + * Sometimes the initial GOTGCTRL read is wrong, so + * check it again and jump to host mode if that was + * the case. + */ + gotgctl = dwc2_readl(hsotg->regs + GOTGCTL); + if (!(gotgctl & GOTGCTL_CONID_B)) + goto host; if (++count > 250) break; } @@ -3252,6 +3260,7 @@ static void dwc2_conn_id_status_change(struct work_struct *work) spin_unlock_irqrestore(&hsotg->lock, flags); dwc2_hsotg_core_connect(hsotg); } else { +host: /* A-Device connector (Host Mode) */ dev_dbg(hsotg->dev, "connId A\n"); while (!dwc2_is_host_mode(hsotg)) {