From nobody Sun Dec 14 06:20:31 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 BCEAFC00140 for ; Mon, 15 Aug 2022 19:19:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245644AbiHOTTN (ORCPT ); Mon, 15 Aug 2022 15:19:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59116 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344332AbiHOTQZ (ORCPT ); Mon, 15 Aug 2022 15:16:25 -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 EFF3752FC1; Mon, 15 Aug 2022 11:38:04 -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 52D34B8108B; Mon, 15 Aug 2022 18:38:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 93F63C433B5; Mon, 15 Aug 2022 18:38:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660588682; bh=Gz2Jr+pS+jA08IitzJi1AbwCWv5VZEhjC2YGN6UtlOw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EnjMv/B60cdFrhJ4MVeoiZrPcIyRxcpJ1mHewJJoj/ab8HRSh+hwjKMsYudBTF0ZN 25fnz5uyIqU0N+WnbXGA+35dR8wlBoFVRlRz/0ZhXgpVtXnShs9Vk2tqTdEiiMYKXD 3jPH/yJKGxStEiO3V4+6czkzL46b7YApLtLujph0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eugen Hristev , Karl Olsen , Adrian Hunter , Ulf Hansson , Sasha Levin Subject: [PATCH 5.15 481/779] mmc: sdhci-of-at91: fix set_uhs_signaling rewriting of MC1R Date: Mon, 15 Aug 2022 20:02:05 +0200 Message-Id: <20220815180357.816841310@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220815180337.130757997@linuxfoundation.org> References: <20220815180337.130757997@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: Eugen Hristev [ Upstream commit 5987e6ded29d52e42fc7b06aa575c60a25eee38e ] In set_uhs_signaling, the DDR bit is being set by fully writing the MC1R register. This can lead to accidental erase of certain bits in this register. Avoid this by doing a read-modify-write operation. Fixes: d0918764c17b ("mmc: sdhci-of-at91: fix MMC_DDR_52 timing selection") Signed-off-by: Eugen Hristev Tested-by: Karl Olsen Acked-by: Adrian Hunter Link: https://lore.kernel.org/r/20220630090926.15061-1-eugen.hristev@microc= hip.com Signed-off-by: Ulf Hansson Signed-off-by: Sasha Levin --- drivers/mmc/host/sdhci-of-at91.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/host/sdhci-of-at91.c b/drivers/mmc/host/sdhci-of-a= t91.c index d1a1c548c515..0452c312b65e 100644 --- a/drivers/mmc/host/sdhci-of-at91.c +++ b/drivers/mmc/host/sdhci-of-at91.c @@ -100,8 +100,13 @@ static void sdhci_at91_set_clock(struct sdhci_host *ho= st, unsigned int clock) static void sdhci_at91_set_uhs_signaling(struct sdhci_host *host, unsigned int timing) { - if (timing =3D=3D MMC_TIMING_MMC_DDR52) - sdhci_writeb(host, SDMMC_MC1R_DDR, SDMMC_MC1R); + u8 mc1r; + + if (timing =3D=3D MMC_TIMING_MMC_DDR52) { + mc1r =3D sdhci_readb(host, SDMMC_MC1R); + mc1r |=3D SDMMC_MC1R_DDR; + sdhci_writeb(host, mc1r, SDMMC_MC1R); + } sdhci_set_uhs_signaling(host, timing); } =20 --=20 2.35.1