* Recommendation for cherry-pick between 3.18 and 4.4: c61f30a255550
@ 2016-01-27 1:36 Simon Horman
2016-01-27 1:57 ` Kuninori Morimoto
0 siblings, 1 reply; 3+ messages in thread
From: Simon Horman @ 2016-01-27 1:36 UTC (permalink / raw)
To: stable; +Cc: linux-renesas-soc, Magnus Damm, Geert Uytterhoeven
Hi,
I'd like to recommend this commit for stable v3.18 onwards:
commit c61f30a255550bbfc6b83c1ca720661489cac4c0
Author: Geert Uytterhoeven <geert+renesas@glider.be>
Date: Fri Dec 18 11:51:36 2015 +0100
ARM: dts: armadillo800eva Correct extal1 frequency to 24 MHz
This change corrects an long-standing miss-match between the clock speed
specified in the kernel (DTS) and what is actually present in the hardware.
My understanding is that this can result in unexpected behaviour. I believe
Geert can provide more details if needed.
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: Recommendation for cherry-pick between 3.18 and 4.4: c61f30a255550
2016-01-27 1:36 Recommendation for cherry-pick between 3.18 and 4.4: c61f30a255550 Simon Horman
@ 2016-01-27 1:57 ` Kuninori Morimoto
2016-01-27 7:43 ` Geert Uytterhoeven
0 siblings, 1 reply; 3+ messages in thread
From: Kuninori Morimoto @ 2016-01-27 1:57 UTC (permalink / raw)
To: Simon Horman; +Cc: stable, linux-renesas-soc, Magnus Damm, Geert Uytterhoeven
Hi
> commit c61f30a255550bbfc6b83c1ca720661489cac4c0
> Author: Geert Uytterhoeven <geert+renesas@glider.be>
> Date: Fri Dec 18 11:51:36 2015 +0100
>
> ARM: dts: armadillo800eva Correct extal1 frequency to 24 MHz
>
>
> This change corrects an long-standing miss-match between the clock speed
> specified in the kernel (DTS) and what is actually present in the hardware.
> My understanding is that this can result in unexpected behaviour. I believe
> Geert can provide more details if needed.
In my (un trusted) memory, the reason why board has 24MHz instead of 25MHz is that
HW people had noticed that 25MHz clock will be conflict/resonance with HDMI.
Thus they decided to use 24MHz instead. But some schematic is still indicating 25MHz.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Recommendation for cherry-pick between 3.18 and 4.4: c61f30a255550
2016-01-27 1:57 ` Kuninori Morimoto
@ 2016-01-27 7:43 ` Geert Uytterhoeven
0 siblings, 0 replies; 3+ messages in thread
From: Geert Uytterhoeven @ 2016-01-27 7:43 UTC (permalink / raw)
To: Kuninori Morimoto
Cc: Simon Horman, stable, linux-renesas-soc, Magnus Damm,
Geert Uytterhoeven
On Wed, Jan 27, 2016 at 2:57 AM, Kuninori Morimoto
<kuninori.morimoto.gx@renesas.com> wrote:
>> commit c61f30a255550bbfc6b83c1ca720661489cac4c0
>> Author: Geert Uytterhoeven <geert+renesas@glider.be>
>> Date: Fri Dec 18 11:51:36 2015 +0100
>>
>> ARM: dts: armadillo800eva Correct extal1 frequency to 24 MHz
>>
>> This change corrects an long-standing miss-match between the clock speed
>> specified in the kernel (DTS) and what is actually present in the hardware.
>> My understanding is that this can result in unexpected behaviour. I believe
>> Geert can provide more details if needed.
It will cause dividers to be set up incorrectly in drivers, leading to e.g.
slightly off serial baud rates (measured).
> In my (un trusted) memory, the reason why board has 24MHz instead of 25MHz is that
> HW people had noticed that 25MHz clock will be conflict/resonance with HDMI.
> Thus they decided to use 24MHz instead. But some schematic is still indicating 25MHz.
Ah, you have schematics ;-)
That's plausible. All documentation I have says 24 MHz.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 3+ messages in thread
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2016-01-27 1:36 Recommendation for cherry-pick between 3.18 and 4.4: c61f30a255550 Simon Horman
2016-01-27 1:57 ` Kuninori Morimoto
2016-01-27 7:43 ` Geert Uytterhoeven
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