From: Alexandre Belloni <alexandre.belloni@bootlin.com>
To: Vladimir Zapolskiy <vz@mleia.com>
Cc: Gregory CLEMENT <gregory.clement@bootlin.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: LPC3250 periph clock at 13MHz instead of 10.4MHz
Date: Wed, 10 Apr 2019 15:44:43 +0200 [thread overview]
Message-ID: <20190410134443.GD3578@piout.net> (raw)
In-Reply-To: <aa8416ba-c81d-d857-e2b7-4b555455e500@mleia.com>
Hi Vladimir,
On 13/02/2019 19:21:44+0200, Vladimir Zapolskiy wrote:
> > Am I missing something?
> >
>
> I think I encountered quite a similar issue previously, but under another
> circumstances, when I begin to modify HCLK PLL clock rate, can you check
> my comment at https://lore.kernel.org/linux-clk/56D685F6.5060400@mleia.com/
> and verify if it's about the same problem?
>
> Since the problem hits you also, I plan to spend some time on this weekend
> to capture more details, fortunately there is a known workaround to pin
> UART input clock rate to 13MHz, it might be desired to carve it in the code.
>
I'm pretty sure this is the same issue and that it doesn't only affect
the UARTs but also timers.
The 2.6.27.8 kernel code would indicated that the timers are only driven
by sysclk, that is either 13MHz from the oscillator or 13.008896 from
PLL397. I'm wondering how many other peripherals are affected.
--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
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next prev parent reply other threads:[~2019-04-10 13:45 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-12 16:52 LPC3250 periph clock at 13MHz instead of 10.4MHz Alexandre Belloni
2019-02-13 17:21 ` Vladimir Zapolskiy
2019-04-10 13:44 ` Alexandre Belloni [this message]
2019-04-10 14:18 ` Alexandre Belloni
2019-04-11 9:15 ` Alexandre Belloni
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