From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:57142 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756670AbbIZVHS (ORCPT ); Sat, 26 Sep 2015 17:07:18 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Yangbo Lu , Joakim Tjernlund , Ulf Hansson Subject: [PATCH 4.2 107/134] mmc: sdhci-of-esdhc: add workaround for pre divider initial value Date: Sat, 26 Sep 2015 13:55:59 -0700 Message-Id: <20150926205318.307112034@linuxfoundation.org> In-Reply-To: <20150926205311.819185658@linuxfoundation.org> References: <20150926205311.819185658@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: stable-owner@vger.kernel.org List-ID: 4.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yangbo Lu commit 77bd2f6f6c65b4ad259394d416855ed561f21e8f upstream. For eSDHC(version < 2.3), the pre divider only could divide base clock by 2 at least. Add workaround for this to avoid unexpected issue. Signed-off-by: Yangbo Lu Acked-by: Joakim Tjernlund Fixes: bd455029d01c ("mmc: sdhci-of-esdhc: Pre divider starts at 1") Signed-off-by: Ulf Hansson Signed-off-by: Greg Kroah-Hartman --- drivers/mmc/host/sdhci-of-esdhc.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/drivers/mmc/host/sdhci-of-esdhc.c +++ b/drivers/mmc/host/sdhci-of-esdhc.c @@ -208,6 +208,12 @@ static void esdhc_of_set_clock(struct sd if (clock == 0) return; + /* Workaround to start pre_div at 2 for VNN < VENDOR_V_23 */ + temp = esdhc_readw(host, SDHCI_HOST_VERSION); + temp = (temp & SDHCI_VENDOR_VER_MASK) >> SDHCI_VENDOR_VER_SHIFT; + if (temp < VENDOR_V_23) + pre_div = 2; + /* Workaround to reduce the clock frequency for p1010 esdhc */ if (of_find_compatible_node(NULL, NULL, "fsl,p1010-esdhc")) { if (clock > 20000000)