From: dbaryshkov@gmail.com (Dmitry Eremin-Solenikov)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 1/5] arm: sa1100: add cpu clock
Date: Tue, 12 Nov 2013 14:37:51 +0400 [thread overview]
Message-ID: <528204FF.8010503@gmail.com> (raw)
In-Reply-To: <20131112095706.GE16735@n2100.arm.linux.org.uk>
On 11/12/2013 01:57 PM, Russell King - ARM Linux wrote:
> On Tue, Nov 12, 2013 at 07:32:08AM +0400, Dmitry Eremin-Solenikov wrote:
>> Both SA1100 framebuffer and PCMCIA drivers require knowledge of cpu
>> frequency to correctly program timings. Currently they receive timing
>> information by calling cpufreq_get(0). However if cpu frequency driver
>> is not enabled (e.g. due to unsupported DRAM chip/board on sa1110)
>> cpufreq_get(0) returns 0, causing incorrect timings to be programmed.
>
> I added a select statement back in 1937f5b91833e2e8e53bcc821fc7a5fbe6ccb9b5
> which avoids this problem. Does this not work?
No, it does not.
1) For collie (sa1110) we don't have dram chip timings in table, so the
cpufreq driver is not registered and cpufreq_get() returns 0
2) What if I want to build a kernel w/o cpu freq? We have clocks exactly
for this reasons - to let drivers get frequency information.
3) And last but not least - PXA uses clocks in this place.
--
With best wishes
Dmitry
next prev parent reply other threads:[~2013-11-12 10:37 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-12 3:32 [PATCH 1/5] arm: sa1100: add cpu clock Dmitry Eremin-Solenikov
2013-11-12 3:32 ` [PATCH 2/5] fbdev: sa1100fb: make use of device clock Dmitry Eremin-Solenikov
2013-11-12 3:32 ` [PATCH 3/5] pcmcia: sa1100: " Dmitry Eremin-Solenikov
2013-11-12 3:32 ` [PATCH 4/5] arm: sa1100: add a clock alias for sa1111 pcmcia device Dmitry Eremin-Solenikov
2013-11-12 12:00 ` Dmitry Artamonow
2013-11-12 3:32 ` [PATCH 5/5] pcmcia: sa1111: make use of device clock Dmitry Eremin-Solenikov
2013-11-12 9:57 ` [PATCH 1/5] arm: sa1100: add cpu clock Russell King - ARM Linux
2013-11-12 10:37 ` Dmitry Eremin-Solenikov [this message]
-- strict thread matches above, loose matches on Subject: below --
2014-10-24 10:37 [PATCH 0/5] arm: sa1100: fix sa1100 fb and pcmcia w/o cpufreq Dmitry Eremin-Solenikov
2014-10-24 10:37 ` [PATCH 1/5] arm: sa1100: add cpu clock Dmitry Eremin-Solenikov
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