[2/2] arc: axs10x: Fix ARC PGU default clock frequency

Message ID 16273b3a26ec770f8d169f04f7cb9eb2fac55909.1487787376.git.joabreu@synopsys.com
State New
Headers show

Commit Message

Jose Abreu Feb. 22, 2017, 6:19 p.m.
Default clock frequency for ARC PGU does not match any
existing HDMI mode, instead the default value matches a
DVI mode. Change the clock frequency to 74.25MHz so that
it matches HDMI mode 1280x720@60Hz

Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Cc: Carlos Palminha <palminha@synopsys.com>
Cc: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: devicetree@vger.kernel.org
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
---
 arch/arc/boot/dts/axs10x_mb.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Alexey Brodkin March 2, 2017, 5:35 p.m. | #1
Hi Jose,

On Wed, 2017-02-22 at 18:19 +0000, Jose Abreu wrote:
> Default clock frequency for ARC PGU does not match any

> existing HDMI mode, instead the default value matches a

> DVI mode. Change the clock frequency to 74.25MHz so that

> it matches HDMI mode 1280x720@60Hz

> 

> Signed-off-by: Jose Abreu <joabreu@synopsys.com>

> Cc: Carlos Palminha <palminha@synopsys.com>

> Cc: Alexey Brodkin <abrodkin@synopsys.com>

> Cc: Rob Herring <robh+dt@kernel.org>

> Cc: Vineet Gupta <vgupta@synopsys.com>

> Cc: devicetree@vger.kernel.org

> Cc: linux-snps-arc@lists.infradead.org

> Cc: linux-kernel@vger.kernel.org

> ---

>  arch/arc/boot/dts/axs10x_mb.dtsi | 2 +-

>  1 file changed, 1 insertion(+), 1 deletion(-)

> 

> diff --git a/arch/arc/boot/dts/axs10x_mb.dtsi b/arch/arc/boot/dts/axs10x_mb.dtsi

> index 9d882b1..41cfb29 100644

> --- a/arch/arc/boot/dts/axs10x_mb.dtsi

> +++ b/arch/arc/boot/dts/axs10x_mb.dtsi

> @@ -51,7 +51,7 @@

>  			pguclk: pguclk {

>  				#clock-cells = <0>;

>  				compatible = "fixed-clock";

> -				clock-frequency = <74440000>;

> +				clock-frequency = <74250000>;

>  			};

>  		};


Looks good to me but I have to note that with this change in place
monitors that don't report [correct] EDID won't work just because
if EDID is missing Linux kernel calculates pixel clock on its
own and for 1280x720@60 it gets 74.40 MHz which obviously differs from
yours 74.25 MHz and so arc_pgu_crtc_atomic_check() returns -EINVAL.

But with the fix I just sent, see
http://lists.infradead.org/pipermail/linux-snps-arc/2017-March/002173.html
everything will work again.

And once Vlad's patch for AXS PLLs gets accepted we'll finally get
support of multiple modes on AXS10x boards.

That said...

Acked-by: Alexey Brodkin <abrodkin@synopsys.com>

Patch

diff --git a/arch/arc/boot/dts/axs10x_mb.dtsi b/arch/arc/boot/dts/axs10x_mb.dtsi
index 9d882b1..41cfb29 100644
--- a/arch/arc/boot/dts/axs10x_mb.dtsi
+++ b/arch/arc/boot/dts/axs10x_mb.dtsi
@@ -51,7 +51,7 @@ 
 			pguclk: pguclk {
 				#clock-cells = <0>;
 				compatible = "fixed-clock";
-				clock-frequency = <74440000>;
+				clock-frequency = <74250000>;
 			};
 		};