From mboxrd@z Thu Jan 1 00:00:00 1970 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 2C1EDC433F5 for ; Mon, 10 Oct 2022 07:15:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232304AbiJJHPx (ORCPT ); Mon, 10 Oct 2022 03:15:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40678 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232285AbiJJHNz (ORCPT ); Mon, 10 Oct 2022 03:13:55 -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 5964D5F21F; Mon, 10 Oct 2022 00:09:31 -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 64744B80E5A; Mon, 10 Oct 2022 07:08:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B9E23C433B5; Mon, 10 Oct 2022 07:08:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1665385702; bh=RLwkL8G/ETNCz7CmD56dJWh6dYl1zvTEvvSe99DyhY0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JG80CpALNkP+XBQpnXL7z+xiL8SvE2akUhub0Gows1yTJ0vHdX08IhYrZIHLrxsGa l3ocKNGjHxWw2LbHcCa8aBJ/2N2ZBHzx4ralPvxSNjlYT4AZtwonSuTSI4eBtKKjTL xs2bqDY4LIxjmNiMO/9hSekOdzQobiCBAlS5iKjY= 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 5.15 29/37] mmc: core: Terminate infinite loop in SD-UHS voltage switch Date: Mon, 10 Oct 2022 09:05:48 +0200 Message-Id: <20221010070332.048029284@linuxfoundation.org> X-Mailer: git-send-email 2.38.0 In-Reply-To: <20221010070331.211113813@linuxfoundation.org> References: <20221010070331.211113813@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 seconds. ... Fixes: f2119df6b764 ("mmc: sd: add support for signal voltage switch procedure") Cc: Signed-off-by: Brian Norris Reviewed-by: Guenter Roeck Link: https://lore.kernel.org/r/20220914014010.2076169-1-briannorris@chromium.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 eaa2679b9466..86a8a1f56583 100644 --- a/drivers/mmc/core/sd.c +++ b/drivers/mmc/core/sd.c @@ -863,7 +863,8 @@ 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 = mmc_set_uhs_voltage(host, pocr); if (err == -EAGAIN) { retries--; -- 2.35.1