From patchwork Fri Mar 1 08:36:09 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Heikki Krogerus X-Patchwork-Id: 2200621 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork1.kernel.org (Postfix) with ESMTP id DF10B3FCA4 for ; Fri, 1 Mar 2013 08:38:46 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UBLRx-0005Uh-Vb; Fri, 01 Mar 2013 08:36:17 +0000 Received: from mga11.intel.com ([192.55.52.93]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UBLRu-0005Tv-Aq for linux-arm-kernel@lists.infradead.org; Fri, 01 Mar 2013 08:36:16 +0000 Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga102.fm.intel.com with ESMTP; 01 Mar 2013 00:36:12 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,760,1355126400"; d="scan'208";a="297638624" Received: from kuha.fi.intel.com ([10.237.72.54]) by fmsmga002.fm.intel.com with ESMTP; 01 Mar 2013 00:36:10 -0800 From: Heikki Krogerus To: Jason Cooper Subject: [PATCH] arm: mvebu: Reduce reg-io-width with UARTs Date: Fri, 1 Mar 2013 10:36:09 +0200 Message-Id: <1362126969-32277-1-git-send-email-heikki.krogerus@linux.intel.com> X-Mailer: git-send-email 1.7.10.4 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130301_033615_350535_2BBF97BD X-CRM114-Status: GOOD ( 12.33 ) X-Spam-Score: -7.6 (-------) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-7.6 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at http://www.dnswl.org/, high trust [192.55.52.93 listed in list.dnswl.org] -0.7 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Gregory CLEMENT , Masami Hiramatsu , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Setting the reg-io-width to 1 byte represents more accurate description of the HW. This will fix an issue where UART driver causes kernel panic during bootup. Gregory CLEMENT traced the issue to autoconfig() in 8250.c, where the existence of FIFO is checked from UART_IIR register. The register is now read as 32-bit value as the reg-io-width is set to 4-bytes. The retuned value seems to contain bogus data for bits 31:8, causing the issue. Signed-off-by: Heikki Krogerus Cc: Gregory CLEMENT Cc: Masami Hiramatsu Tested-by: Gregory CLEMENT Acked-by: Gregory CLEMENT Tested-by: Masami Hiramatsu --- arch/arm/boot/dts/armada-370-xp.dtsi | 4 ++-- arch/arm/boot/dts/armada-xp.dtsi | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/arm/boot/dts/armada-370-xp.dtsi b/arch/arm/boot/dts/armada-370-xp.dtsi index 6f1acc7..99afca4 100644 --- a/arch/arm/boot/dts/armada-370-xp.dtsi +++ b/arch/arm/boot/dts/armada-370-xp.dtsi @@ -54,7 +54,7 @@ reg = <0xd0012000 0x100>; reg-shift = <2>; interrupts = <41>; - reg-io-width = <4>; + reg-io-width = <1>; status = "disabled"; }; serial@d0012100 { @@ -62,7 +62,7 @@ reg = <0xd0012100 0x100>; reg-shift = <2>; interrupts = <42>; - reg-io-width = <4>; + reg-io-width = <1>; status = "disabled"; }; diff --git a/arch/arm/boot/dts/armada-xp.dtsi b/arch/arm/boot/dts/armada-xp.dtsi index 1443949..ca00d83 100644 --- a/arch/arm/boot/dts/armada-xp.dtsi +++ b/arch/arm/boot/dts/armada-xp.dtsi @@ -46,7 +46,7 @@ reg = <0xd0012200 0x100>; reg-shift = <2>; interrupts = <43>; - reg-io-width = <4>; + reg-io-width = <1>; status = "disabled"; }; serial@d0012300 { @@ -54,7 +54,7 @@ reg = <0xd0012300 0x100>; reg-shift = <2>; interrupts = <44>; - reg-io-width = <4>; + reg-io-width = <1>; status = "disabled"; };