[U-Boot] [PATCH] ARMV7: Overo: Automatically set clock rate to maximum if mpurate env variable is "auto"

[U-Boot] [PATCH] ARMV7: Overo: Automatically set clock rate to maximum if mpurate env variable is "auto"

[Steve Sakoman]

The maximum clock rate for the OMAP3 processors on Overo depends on the
processor type and revision.  This patch sets the clock rate to the
spec sheet maximum if the mpurate environment variable is set to
"auto".  Otherwise it passes the mpurate variable unchanged on the
kernel command line.

Signed-off-by: Steve Sakoman <steve.sakoman@linaro.org>
---

diff --git a/board/overo/overo.c b/board/overo/overo.c
index f917e40..3c9e4a6 100644
--- a/board/overo/overo.c
+++ b/board/overo/overo.c
@@ -281,6 +281,22 @@ int misc_init_r(void)
 
 	dieid_num_r();
 
+	if (strcmp(getenv("mpurate"), "auto") == 0)
+		switch (get_cpu_family()) {
+		case CPU_OMAP34XX:
+			if ((get_cpu_rev() >= CPU_3XX_ES31) &&
+			    (get_sku_id() == SKUID_CLK_720MHZ))
+				setenv("mpurate", "720");
+			else
+				setenv("mpurate", "600");
+			break;
+		case CPU_OMAP36XX:
+			setenv("mpurate", "720");
+			break;
+		default:
+			setenv("mpurate", "500");
+		}
+
 	return 0;
 }
 
diff --git a/include/configs/omap3_overo.h b/include/configs/omap3_overo.h
index 79a5b85..dbdfd9a 100644
--- a/include/configs/omap3_overo.h
+++ b/include/configs/omap3_overo.h
@@ -156,7 +156,7 @@
 #define CONFIG_EXTRA_ENV_SETTINGS \
 	"loadaddr=0x82000000\0" \
 	"console=ttyS2,115200n8\0" \
-	"mpurate=500\0" \
+	"mpurate=auto\0" \
 	"vram=12M\0" \
 	"dvimode=1024x768MR-16 at 60\0" \
 	"defaultdisplay=dvi\0" \

[U-Boot] [PATCH] ARMV7: Overo: Automatically set clock rate to maximum if mpurate env variable is "auto"

[Nishanth Menon]

just a minor crib - $subject length is around 88 characters, it'd look 
better with around 50 character length.

Steve Sakoman wrote, on 11/05/2010 10:59 PM:
> The maximum clock rate for the OMAP3 processors on Overo depends on the
> processor type and revision.  This patch sets the clock rate to the
> spec sheet maximum if the mpurate environment variable is set to
> "auto".  Otherwise it passes the mpurate variable unchanged on the
> kernel command line.
>
> Signed-off-by: Steve Sakoman<steve.sakoman@linaro.org>
> ---
>
> diff --git a/board/overo/overo.c b/board/overo/overo.c
> index f917e40..3c9e4a6 100644
> --- a/board/overo/overo.c
> +++ b/board/overo/overo.c
> @@ -281,6 +281,22 @@ int misc_init_r(void)
>
>   	dieid_num_r();
>
> +	if (strcmp(getenv("mpurate"), "auto") == 0)
> +		switch (get_cpu_family()) {
> +		case CPU_OMAP34XX:
> +			if ((get_cpu_rev()>= CPU_3XX_ES31)&&
> +			    (get_sku_id() == SKUID_CLK_720MHZ))
> +				setenv("mpurate", "720");
> +			else
> +				setenv("mpurate", "600");
> +			break;
> +		case CPU_OMAP36XX:
> +			setenv("mpurate", "720");
> +			break;
> +		default:
> +			setenv("mpurate", "500");
> +		}
> +
>   	return 0;
>   }
>
> diff --git a/include/configs/omap3_overo.h b/include/configs/omap3_overo.h
> index 79a5b85..dbdfd9a 100644
> --- a/include/configs/omap3_overo.h
> +++ b/include/configs/omap3_overo.h
> @@ -156,7 +156,7 @@
>   #define CONFIG_EXTRA_ENV_SETTINGS \
>   	"loadaddr=0x82000000\0" \
>   	"console=ttyS2,115200n8\0" \
> -	"mpurate=500\0" \
> +	"mpurate=auto\0" \
>   	"vram=12M\0" \
>   	"dvimode=1024x768MR-16 at 60\0" \
>   	"defaultdisplay=dvi\0" \

yep, this does look like a nice way to do it. thanks.

-- 
Regards,
Nishanth Menon

[U-Boot] [PATCH] ARMV7: Overo: Automatically set clock rate to maximum if mpurate env variable is "auto"

[Wolfgang Denk]

Dear Steve Sakoman,

In message <1289012370.18546.66.camel@quadra> you wrote:
> The maximum clock rate for the OMAP3 processors on Overo depends on the
> processor type and revision.  This patch sets the clock rate to the
> spec sheet maximum if the mpurate environment variable is set to
> "auto".  Otherwise it passes the mpurate variable unchanged on the
> kernel command line.

I don't think this is a good idea.

This logic does not belong into U-Boot; if anywhere, it belongs into
the Linux kernel code.  If I want to pass any specific value to the
Linux kernel I want that U-Boot does not get in my way. And if I
decide to set the mpurate to "auto" I want that U-Boot keeps this
setting and does not change it silently behind my back into something
else.

Both looks conceptually broken to me.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
It became apparent that one reason why the Ice Giants were  known  as
the  Ice  Giants  was  because they were, well, giants. The other was
that they were made of ice.              -Terry Pratchett, _Sourcery_

[U-Boot] [PATCH] ARMV7: Overo: Automatically set clock rate to maximum if mpurate env variable is "auto"

[Premi, Sanjeev]

> -----Original Message-----
> From: u-boot-bounces at lists.denx.de 
> [mailto:u-boot-bounces at lists.denx.de] On Behalf Of Wolfgang Denk
> Sent: Monday, November 08, 2010 3:14 AM
> To: Steve Sakoman
> Cc: u-boot at lists.denx.de
> Subject: Re: [U-Boot] [PATCH] ARMV7: Overo: Automatically set 
> clock rate to maximum if mpurate env variable is "auto"
> 
> Dear Steve Sakoman,
> 
> In message <1289012370.18546.66.camel@quadra> you wrote:
> > The maximum clock rate for the OMAP3 processors on Overo 
> depends on the
> > processor type and revision.  This patch sets the clock rate to the
> > spec sheet maximum if the mpurate environment variable is set to
> > "auto".  Otherwise it passes the mpurate variable unchanged on the
> > kernel command line.
> 
> I don't think this is a good idea.
> 
> This logic does not belong into U-Boot; if anywhere, it belongs into
> the Linux kernel code.  If I want to pass any specific value to the
> Linux kernel I want that U-Boot does not get in my way. And if I
> decide to set the mpurate to "auto" I want that U-Boot keeps this
> setting and does not change it silently behind my back into something
> else.

[sp] I am in full agreement.
     It is too difficult to find root cause for transparent changes -
     usually lead to long debug times first in kernel an then in u-boot.

~sanjeev

> 
> Both looks conceptually broken to me.
> 
> Best regards,
> 
> Wolfgang Denk
> 
> -- 
> DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
> It became apparent that one reason why the Ice Giants were  known  as
> the  Ice  Giants  was  because they were, well, giants. The other was
> that they were made of ice.              -Terry Pratchett, _Sourcery_
> _______________________________________________
> U-Boot mailing list
> U-Boot at lists.denx.de
> http://lists.denx.de/mailman/listinfo/u-boot
>