From nobody Fri Dec 19 20:33:08 2025 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 EC5EBC4332F for ; Thu, 13 Oct 2022 18:44:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232184AbiJMSoo (ORCPT ); Thu, 13 Oct 2022 14:44:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58110 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232179AbiJMSnf (ORCPT ); Thu, 13 Oct 2022 14:43:35 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 671A932BA0; Thu, 13 Oct 2022 11:41:35 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 828A9B82033; Thu, 13 Oct 2022 17:55:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DB858C433D6; Thu, 13 Oct 2022 17:55:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1665683729; bh=bG6X3+WJsB9jgX3tUXAaHu7yd9226itCgN/0YmmAHgk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JFIiQv+ZReVZmSZOBVOLJoXtmsMExTrBVeIZQt973nZCfXO8jkvq5bYldBxlmhqtW 1XHPAq2/kXHF5CJkt4vKCwKzeiOzgG7BxU+/lyQkXFtcc3X4TZ5qaARIqIPIWBObTj DZeJI2aVdfv49DXvgJCISRg5zeYwdwa9HX9LCK2c= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Brian Norris , Guenter Roeck , Ulf Hansson , Sasha Levin Subject: [PATCH 5.10 30/54] mmc: core: Terminate infinite loop in SD-UHS voltage switch Date: Thu, 13 Oct 2022 19:52:24 +0200 Message-Id: <20221013175148.084994323@linuxfoundation.org> X-Mailer: git-send-email 2.38.0 In-Reply-To: <20221013175147.337501757@linuxfoundation.org> References: <20221013175147.337501757@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Brian Norris [ Upstream commit e9233917a7e53980664efbc565888163c0a33c3f ] This loop intends to retry a max of 10 times, with some implicit termination based on the SD_{R,}OCR_S18A bit. Unfortunately, the termination condition depends on the value reported by the SD card (*rocr), which may or may not correctly reflect what we asked it to do. Needless to say, it's not wise to rely on the card doing what we expect; we should at least terminate the loop regardless. So, check both the input and output values, so we ensure we will terminate regardless of the SD card behavior. Note that SDIO learned a similar retry loop in commit 0797e5f1453b ("mmc: core: Fixup signal voltage switch"), but that used the 'ocr' result, and so the current pre-terminating condition looks like: rocr & ocr & R4_18V_PRESENT (i.e., it doesn't have the same bug.) This addresses a number of crash reports seen on ChromeOS that look like the following: ... // lots of repeated: ... <4>[13142.846061] mmc1: Skipping voltage switch <4>[13143.406087] mmc1: Skipping voltage switch <4>[13143.964724] mmc1: Skipping voltage switch <4>[13144.526089] mmc1: Skipping voltage switch <4>[13145.086088] mmc1: Skipping voltage switch <4>[13145.645941] mmc1: Skipping voltage switch <3>[13146.153969] INFO: task halt:30352 blocked for more than 122 secon= ds. ... Fixes: f2119df6b764 ("mmc: sd: add support for signal voltage switch proced= ure") Cc: Signed-off-by: Brian Norris Reviewed-by: Guenter Roeck Link: https://lore.kernel.org/r/20220914014010.2076169-1-briannorris@chromi= um.org Signed-off-by: Ulf Hansson Signed-off-by: Sasha Levin --- drivers/mmc/core/sd.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index e2c34aa390f1..868b121ce4f3 100644 --- a/drivers/mmc/core/sd.c +++ b/drivers/mmc/core/sd.c @@ -853,7 +853,8 @@ int mmc_sd_get_cid(struct mmc_host *host, u32 ocr, u32 = *cid, u32 *rocr) * the CCS bit is set as well. We deliberately deviate from the spec in * regards to this, which allows UHS-I to be supported for SDSC cards. */ - if (!mmc_host_is_spi(host) && rocr && (*rocr & SD_ROCR_S18A)) { + if (!mmc_host_is_spi(host) && (ocr & SD_OCR_S18R) && + rocr && (*rocr & SD_ROCR_S18A)) { err =3D mmc_set_uhs_voltage(host, pocr); if (err =3D=3D -EAGAIN) { retries--; --=20 2.35.1