From mboxrd@z Thu Jan 1 00:00:00 1970 From: thomas.petazzoni@free-electrons.com (Thomas Petazzoni) Date: Wed, 6 Mar 2013 11:23:33 +0100 Subject: [PATCH 1/4] arm: mvebu: Reduce reg-io-width with UARTs In-Reply-To: <1362565416-15718-1-git-send-email-thomas.petazzoni@free-electrons.com> References: <1362565416-15718-1-git-send-email-thomas.petazzoni@free-electrons.com> Message-ID: <1362565416-15718-2-git-send-email-thomas.petazzoni@free-electrons.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Heikki Krogerus 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 Tested-by: Thomas Petazzoni --- 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 at 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 at d0012300 { @@ -54,7 +54,7 @@ reg = <0xd0012300 0x100>; reg-shift = <2>; interrupts = <44>; - reg-io-width = <4>; + reg-io-width = <1>; status = "disabled"; }; -- 1.7.9.5