From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Date: Mon, 02 Feb 2015 22:10:57 +0000 Subject: Re: [PATCH] ARM: shmobile: alt dts: Drop console= bootargs parameter Message-Id: <54CFF5F1.2040007@cogentembedded.com> List-Id: References: <1415075018-27529-1-git-send-email-horms+renesas@verge.net.au> <54CBFC63.4070808@cogentembedded.com> <20150131041731.GA7605@verge.net.au> In-Reply-To: <20150131041731.GA7605@verge.net.au> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org Hello. On 01/31/2015 07:17 AM, Simon Horman wrote: >>> Alt is booted from DT, so chosen/stdout-path is >>> always used, and we can drop the "console=" parameter from chosen/bootargs. >>> This change has a side-effect of changing the console speed from 38400 >>> to 115200. This is intentional as 115200 is consistently used on >>> all other shmobile boards. >> I'd say it's not very practical to change the console's baud rate from >> U-Boot's default > It is consistent with the handling of all other boards with > renesas SoCs that are present in mainline. Well, not quite: Henninger/Porter is still using 38400. >> (AFAIR changing baud rate in U-Boot didn't work)... That was a recollection from the other board though, I haven't yet tried to do it on the SILK board (and I'm unable to currently as the power supply seems dead). > Perhaps that relates to the version of built of uboot. > On the board I have access to I see: > ver=U-Boot 2013.01.01-g5df9446 (Oct 01 2014 - 14:59:23) U-Boot 2013.01.01 (Oct 17 2014 - 20:59:18) > And the following setting altered the baud rate of u-boot (IIRC). > baudrate5200 I was going to try that but the board just didn't power up. >>> Cc: Ulrich Hecht >>> Cc: Geert Uytterhoeven >>> Cc: devicetree@vger.kernel.org >>> Signed-off-by: Simon Horman >>> --- >>> arch/arm/boot/dts/r8a7794-alt.dts | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> diff --git a/arch/arm/boot/dts/r8a7794-alt.dts b/arch/arm/boot/dts/r8a7794-alt.dts >>> index 8aec512..f2cf757 100644 >>> --- a/arch/arm/boot/dts/r8a7794-alt.dts >>> +++ b/arch/arm/boot/dts/r8a7794-alt.dts >>> @@ -20,7 +20,7 @@ >>> }; >>> >>> chosen { >>> - bootargs = "console=ttySC0,38400 ignore_loglevel rw root=/dev/nfs ip=dhcp"; >>> + bootargs = "ignore_loglevel rw root=/dev/nfs ip=dhcp"; >> Hm, does this even work as intended? I've tried to boot another R8A7794 >> based board and I couldn't get any output with alike command line. Booting >> with 'earlyprintk=serial' has shown that tty0 was enabled as a console which >> is not what we wanted. > If you are backporting this change then I believe it has some dependencies > that I can follow up on if it is useful to you. Contrariwise, I'm forward-porting. > If you are using mainline (e.g. next or renesas-next) then yes, > it works. I have tested it numerous times since the patch was merged. I'm traditionally using the 'renesas-devel-*' tags. WBR, Sergei From mboxrd@z Thu Jan 1 00:00:00 1970 From: sergei.shtylyov@cogentembedded.com (Sergei Shtylyov) Date: Tue, 03 Feb 2015 01:10:57 +0300 Subject: [PATCH] ARM: shmobile: alt dts: Drop console= bootargs parameter In-Reply-To: <20150131041731.GA7605@verge.net.au> References: <1415075018-27529-1-git-send-email-horms+renesas@verge.net.au> <54CBFC63.4070808@cogentembedded.com> <20150131041731.GA7605@verge.net.au> Message-ID: <54CFF5F1.2040007@cogentembedded.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hello. On 01/31/2015 07:17 AM, Simon Horman wrote: >>> Alt is booted from DT, so chosen/stdout-path is >>> always used, and we can drop the "console=" parameter from chosen/bootargs. >>> This change has a side-effect of changing the console speed from 38400 >>> to 115200. This is intentional as 115200 is consistently used on >>> all other shmobile boards. >> I'd say it's not very practical to change the console's baud rate from >> U-Boot's default > It is consistent with the handling of all other boards with > renesas SoCs that are present in mainline. Well, not quite: Henninger/Porter is still using 38400. >> (AFAIR changing baud rate in U-Boot didn't work)... That was a recollection from the other board though, I haven't yet tried to do it on the SILK board (and I'm unable to currently as the power supply seems dead). > Perhaps that relates to the version of built of uboot. > On the board I have access to I see: > ver=U-Boot 2013.01.01-g5df9446 (Oct 01 2014 - 14:59:23) U-Boot 2013.01.01 (Oct 17 2014 - 20:59:18) > And the following setting altered the baud rate of u-boot (IIRC). > baudrate=115200 I was going to try that but the board just didn't power up. >>> Cc: Ulrich Hecht >>> Cc: Geert Uytterhoeven >>> Cc: devicetree at vger.kernel.org >>> Signed-off-by: Simon Horman >>> --- >>> arch/arm/boot/dts/r8a7794-alt.dts | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> diff --git a/arch/arm/boot/dts/r8a7794-alt.dts b/arch/arm/boot/dts/r8a7794-alt.dts >>> index 8aec512..f2cf757 100644 >>> --- a/arch/arm/boot/dts/r8a7794-alt.dts >>> +++ b/arch/arm/boot/dts/r8a7794-alt.dts >>> @@ -20,7 +20,7 @@ >>> }; >>> >>> chosen { >>> - bootargs = "console=ttySC0,38400 ignore_loglevel rw root=/dev/nfs ip=dhcp"; >>> + bootargs = "ignore_loglevel rw root=/dev/nfs ip=dhcp"; >> Hm, does this even work as intended? I've tried to boot another R8A7794 >> based board and I couldn't get any output with alike command line. Booting >> with 'earlyprintk=serial' has shown that tty0 was enabled as a console which >> is not what we wanted. > If you are backporting this change then I believe it has some dependencies > that I can follow up on if it is useful to you. Contrariwise, I'm forward-porting. > If you are using mainline (e.g. next or renesas-next) then yes, > it works. I have tested it numerous times since the patch was merged. I'm traditionally using the 'renesas-devel-*' tags. WBR, Sergei From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [PATCH] ARM: shmobile: alt dts: Drop console= bootargs parameter Date: Tue, 03 Feb 2015 01:10:57 +0300 Message-ID: <54CFF5F1.2040007@cogentembedded.com> References: <1415075018-27529-1-git-send-email-horms+renesas@verge.net.au> <54CBFC63.4070808@cogentembedded.com> <20150131041731.GA7605@verge.net.au> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20150131041731.GA7605@verge.net.au> Sender: linux-sh-owner@vger.kernel.org To: Simon Horman Cc: linux-sh@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Magnus Damm , Ulrich Hecht , Geert Uytterhoeven , devicetree@vger.kernel.org List-Id: devicetree@vger.kernel.org Hello. On 01/31/2015 07:17 AM, Simon Horman wrote: >>> Alt is booted from DT, so chosen/stdout-path is >>> always used, and we can drop the "console=" parameter from chosen/bootargs. >>> This change has a side-effect of changing the console speed from 38400 >>> to 115200. This is intentional as 115200 is consistently used on >>> all other shmobile boards. >> I'd say it's not very practical to change the console's baud rate from >> U-Boot's default > It is consistent with the handling of all other boards with > renesas SoCs that are present in mainline. Well, not quite: Henninger/Porter is still using 38400. >> (AFAIR changing baud rate in U-Boot didn't work)... That was a recollection from the other board though, I haven't yet tried to do it on the SILK board (and I'm unable to currently as the power supply seems dead). > Perhaps that relates to the version of built of uboot. > On the board I have access to I see: > ver=U-Boot 2013.01.01-g5df9446 (Oct 01 2014 - 14:59:23) U-Boot 2013.01.01 (Oct 17 2014 - 20:59:18) > And the following setting altered the baud rate of u-boot (IIRC). > baudrate=115200 I was going to try that but the board just didn't power up. >>> Cc: Ulrich Hecht >>> Cc: Geert Uytterhoeven >>> Cc: devicetree@vger.kernel.org >>> Signed-off-by: Simon Horman >>> --- >>> arch/arm/boot/dts/r8a7794-alt.dts | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> diff --git a/arch/arm/boot/dts/r8a7794-alt.dts b/arch/arm/boot/dts/r8a7794-alt.dts >>> index 8aec512..f2cf757 100644 >>> --- a/arch/arm/boot/dts/r8a7794-alt.dts >>> +++ b/arch/arm/boot/dts/r8a7794-alt.dts >>> @@ -20,7 +20,7 @@ >>> }; >>> >>> chosen { >>> - bootargs = "console=ttySC0,38400 ignore_loglevel rw root=/dev/nfs ip=dhcp"; >>> + bootargs = "ignore_loglevel rw root=/dev/nfs ip=dhcp"; >> Hm, does this even work as intended? I've tried to boot another R8A7794 >> based board and I couldn't get any output with alike command line. Booting >> with 'earlyprintk=serial' has shown that tty0 was enabled as a console which >> is not what we wanted. > If you are backporting this change then I believe it has some dependencies > that I can follow up on if it is useful to you. Contrariwise, I'm forward-porting. > If you are using mainline (e.g. next or renesas-next) then yes, > it works. I have tested it numerous times since the patch was merged. I'm traditionally using the 'renesas-devel-*' tags. WBR, Sergei