From patchwork Tue May 18 23:43:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Marangi X-Patchwork-Id: 441548 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EB2A6C433ED for ; Tue, 18 May 2021 23:43:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CC2DC6112F for ; Tue, 18 May 2021 23:43:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235382AbhERXod (ORCPT ); Tue, 18 May 2021 19:44:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39342 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230114AbhERXod (ORCPT ); Tue, 18 May 2021 19:44:33 -0400 Received: from mail-ej1-x636.google.com (mail-ej1-x636.google.com [IPv6:2a00:1450:4864:20::636]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 34CD4C061573; Tue, 18 May 2021 16:43:14 -0700 (PDT) Received: by mail-ej1-x636.google.com with SMTP id lg14so17197251ejb.9; Tue, 18 May 2021 16:43:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=x6BN/PyTHg0vWjClj6KF7Z9rFUMiX9eq6dsc19wtdr4=; b=n6wyx8OsDzlIlED4O93DtiZhz6eERcfdK3k6vpm3EXg5zXa+1oUGm01Phbrrpzs5E5 qQ3tdtBZEEq8WSlUxVi2s6/MX6K+dRSVOMGlPGRcbCYXmOZ98RF7KLngTJLuRvkRM2bZ DXUJtqfYPDb7zHt8Kyxccd5hrAG/hjvmfISMkpLyhd7prJ5RoLlvljk37X/Sa3VoK94d 9zpcJJs5+jU7YZfoLm7PPZLZt1ZjlfzqMnOl2EFg+vb9QDqLxZdp570J0cascxregwnP ArFOogQv4PVTn1HGagK12A7ksXTgk1dCRcYDClJtElglk+t436DyUbYSrRI0dyEWIq8g eMcw== 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:mime-version :content-transfer-encoding; bh=x6BN/PyTHg0vWjClj6KF7Z9rFUMiX9eq6dsc19wtdr4=; b=OS+eSAbOyDTWXeTOziUkrVex3I0qXPQPajvq9JP8RlqutYtb8ZAt4OTLx3e9WJXClt xdVFnZ6XK65AqrEz5Zf1fyZsu3GcnbV9sagM22QUTzC9cZKescUF55oYkcCxV3+6DmYm H6ZdwF84QdiHO7WslXQl+2w3dxFDi3SF6y2Y90hObEAXmMAqwj4CQLYvC3EGFrIw8UFn E9c5SnNWr4Ueykpj71l6cUPVa96EE8YfvwzAVvuQPcMA+X0EsdXSyU2PtT5e4/u2AvJ6 jBvKnSV2kzqNO/w1KbWqw9Q7tW7FUoycAg0qiBOU7OKFhpdbscDOVoRtg6mYYH8kNDW6 uLJQ== X-Gm-Message-State: AOAM532Sz6+r/efZcgrBOG1LppOWk6Oc0mLZ3II6jAtx+RHSyPGXim6F +SX8y8TuNVnwrQ2HMegID30= X-Google-Smtp-Source: ABdhPJyx4g0eF9jK3jR9GNaW4zcqF2TMglN8q9DN3A6CTzKP9unCmlTL3ltDAQYjzDHsTxzjwkO/DQ== X-Received: by 2002:a17:906:640c:: with SMTP id d12mr8429650ejm.70.1621381392638; Tue, 18 May 2021 16:43:12 -0700 (PDT) Received: from Ansuel-xps.localdomain (93-35-189-2.ip56.fastwebnet.it. [93.35.189.2]) by smtp.googlemail.com with ESMTPSA id bm13sm11220567ejb.75.2021.05.18.16.43.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 18 May 2021 16:43:12 -0700 (PDT) From: Ansuel Smith To: Thara Gopinath Cc: Ansuel Smith , Andy Gross , Bjorn Andersson , Amit Kucheria , Zhang Rui , Daniel Lezcano , linux-arm-msm@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/3] drivers: thermal: tsens: add timeout to get_tem_tsens_valid Date: Wed, 19 May 2021 01:43:06 +0200 Message-Id: <20210518234309.29014-1-ansuelsmth@gmail.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org The function can loop and lock the system if for whatever reason the bit for the target sensor is NEVER valid. This is the case if a sensor is disabled by the factory and the valid bit is never reported as actually valid. Add a timeout check and exit if a timeout occurs. As this is a very rare condition, handle the timeout only if the first read fails. Signed-off-by: Ansuel Smith --- drivers/thermal/qcom/tsens.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/drivers/thermal/qcom/tsens.c b/drivers/thermal/qcom/tsens.c index b1162e566a70..38afde1a599f 100644 --- a/drivers/thermal/qcom/tsens.c +++ b/drivers/thermal/qcom/tsens.c @@ -599,6 +599,7 @@ int get_temp_tsens_valid(const struct tsens_sensor *s, int *temp) int hw_id = s->hw_id; u32 temp_idx = LAST_TEMP_0 + hw_id; u32 valid_idx = VALID_0 + hw_id; + unsigned long timeout; u32 valid; int ret; @@ -607,13 +608,21 @@ int get_temp_tsens_valid(const struct tsens_sensor *s, int *temp) ret = regmap_field_read(priv->rf[valid_idx], &valid); if (ret) return ret; - while (!valid) { - /* Valid bit is 0 for 6 AHB clock cycles. - * At 19.2MHz, 1 AHB clock is ~60ns. - * We should enter this loop very, very rarely. - */ - ndelay(400); - ret = regmap_field_read(priv->rf[valid_idx], &valid); + + if (!valid) { + timeout = jiffies + msecs_to_jiffies(20); + + do { + /* Valid bit is 0 for 6 AHB clock cycles. + * At 19.2MHz, 1 AHB clock is ~60ns. + * We should enter this loop very, very rarely. + */ + ndelay(400); + ret = regmap_field_read(priv->rf[valid_idx], &valid); + if (valid || ret) + break; + } while (!(ret = time_after_eq(jiffies, timeout))); + if (ret) return ret; }