Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756836AbdIHSmj (ORCPT ); Fri, 8 Sep 2017 14:42:39 -0400 Received: from smtprelay.synopsys.com ([198.182.47.9]:47041 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756615AbdIHSmh (ORCPT ); Fri, 8 Sep 2017 14:42:37 -0400 From: Eugeniy Paltsev To: linux-snps-arc@lists.infradead.org Cc: linux-kernel@vger.kernel.org, Vineet Gupta , Alexey Brodkin , Rob Herring , devicetree@vger.kernel.org, Eugeniy Paltsev Subject: [PATCH] ARC: HSDK: DTS: Temporary fix of sdio ciu frequency Date: Fri, 8 Sep 2017 21:42:33 +0300 Message-Id: <20170908184233.1779-1-Eugeniy.Paltsev@synopsys.com> X-Mailer: git-send-email 2.9.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1290 Lines: 38 DW sdio controller has external ciu clock devider controlled via register in SDIO IP. Due to its unexpected default value (it should devide by 1 but it devides by 8) SDIO IP uses wrong ciu clock and works unstable (see STAR 9001204800) So add temporary fix and change clock frequency from 100000000 to 12500000 Hz until we fix dw sdio driver itself. Signed-off-by: Eugeniy Paltsev --- arch/arc/boot/dts/hsdk.dts | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/arch/arc/boot/dts/hsdk.dts b/arch/arc/boot/dts/hsdk.dts index 8412669..b922f3f 100644 --- a/arch/arc/boot/dts/hsdk.dts +++ b/arch/arc/boot/dts/hsdk.dts @@ -127,7 +127,17 @@ mmcclk_ciu: mmcclk-ciu { compatible = "fixed-clock"; - clock-frequency = <100000000>; + /* + * DW sdio controller has external ciu clock divider + * controlled via register in SDIO IP. Due to its + * unexpected default value (it should devide by 1 + * but it devides by 8) SDIO IP uses wrong clock and + * works unstable (see STAR 9001204800) + * So add temporary fix and change clock frequency + * from 100000000 to 12500000 Hz until we fix dw sdio + * driver itself. + */ + clock-frequency = <12500000>; #clock-cells = <0>; }; -- 2.9.3