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 X-Spam-Level: X-Spam-Status: No, score=-19.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 A02CBC4338F for ; Tue, 24 Aug 2021 17:01:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 868F861A62 for ; Tue, 24 Aug 2021 17:01:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238619AbhHXRCi (ORCPT ); Tue, 24 Aug 2021 13:02:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:39380 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238633AbhHXRAq (ORCPT ); Tue, 24 Aug 2021 13:00:46 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5365061506; Tue, 24 Aug 2021 16:57:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629824272; bh=nK5MH3n4nmvDkjpNZ4AgOhZtHVbWau0UkJU48ygO+K8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JpGfyNndgL22x/HVp2sDUXI4AVndw6CudpDTYGkQHzfRas73PusAIUQXiju49n37j VRPLDxNKnRIaa5m+LcuLeA5Ym5atbGgzEOgamF0gebezMLgV/PkUgcxQtdXRkC0Fr3 eGIPVyMuiHMKSY5S2GlzROScBZ/E7nMIgW0JQQIbH9c97LRuYvzTNCvEa3+gSiIe9h 66hnm4XKStCXlYJx6s2sSsl0152kCHnLiXmukSOWloXmvNfXcvaTkbcESsbLDkMwHa V/ksJPjJvk202H3VNeuIK/rgoCeQjliVogJPZc1rc7f4ZM3DWJFg0fXPb0bbUiMtLc orjvN0hOHhWtA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Nicolas Saenz Julienne , Stefan Wahren , Ulf Hansson , Sasha Levin Subject: [PATCH 5.13 106/127] mmc: sdhci-iproc: Cap min clock frequency on BCM2711 Date: Tue, 24 Aug 2021 12:55:46 -0400 Message-Id: <20210824165607.709387-107-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210824165607.709387-1-sashal@kernel.org> References: <20210824165607.709387-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v5.x/stable-review/patch-5.13.13-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-5.13.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 5.13.13-rc1 X-KernelTest-Deadline: 2021-08-26T16:55+00:00 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Nicolas Saenz Julienne [ Upstream commit c9107dd0b851777d7e134420baf13a5c5343bc16 ] There is a known bug on BCM2711's SDHCI core integration where the controller will hang when the difference between the core clock and the bus clock is too great. Specifically this can be reproduced under the following conditions: - No SD card plugged in, polling thread is running, probing cards at 100 kHz. - BCM2711's core clock configured at 500MHz or more. So set 200 kHz as the minimum clock frequency available for that board. For more information on the issue see this: https://lore.kernel.org/linux-mmc/20210322185816.27582-1-nsaenz@kernel.org/T/#m11f2783a09b581da6b8a15f302625b43a6ecdeca Fixes: f84e411c85be ("mmc: sdhci-iproc: Add support for emmc2 of the BCM2711") Signed-off-by: Nicolas Saenz Julienne Signed-off-by: Stefan Wahren Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/1628334401-6577-5-git-send-email-stefan.wahren@i2se.com Signed-off-by: Ulf Hansson Signed-off-by: Sasha Levin --- drivers/mmc/host/sdhci-iproc.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/drivers/mmc/host/sdhci-iproc.c b/drivers/mmc/host/sdhci-iproc.c index ddeaf8e1f72f..b9eb2ec61a83 100644 --- a/drivers/mmc/host/sdhci-iproc.c +++ b/drivers/mmc/host/sdhci-iproc.c @@ -173,6 +173,23 @@ static unsigned int sdhci_iproc_get_max_clock(struct sdhci_host *host) return pltfm_host->clock; } +/* + * There is a known bug on BCM2711's SDHCI core integration where the + * controller will hang when the difference between the core clock and the bus + * clock is too great. Specifically this can be reproduced under the following + * conditions: + * + * - No SD card plugged in, polling thread is running, probing cards at + * 100 kHz. + * - BCM2711's core clock configured at 500MHz or more + * + * So we set 200kHz as the minimum clock frequency available for that SoC. + */ +static unsigned int sdhci_iproc_bcm2711_get_min_clock(struct sdhci_host *host) +{ + return 200000; +} + static const struct sdhci_ops sdhci_iproc_ops = { .set_clock = sdhci_set_clock, .get_max_clock = sdhci_iproc_get_max_clock, @@ -271,6 +288,7 @@ static const struct sdhci_ops sdhci_iproc_bcm2711_ops = { .set_clock = sdhci_set_clock, .set_power = sdhci_set_power_and_bus_voltage, .get_max_clock = sdhci_iproc_get_max_clock, + .get_min_clock = sdhci_iproc_bcm2711_get_min_clock, .set_bus_width = sdhci_set_bus_width, .reset = sdhci_reset, .set_uhs_signaling = sdhci_set_uhs_signaling, -- 2.30.2