Re: [PATCH v4 3/3] memory: tegra124-emc: Add EMC driver

From: Tomeu Vizoso
Date: Wed Aug 27 2014 - 03:32:18 EST

On 08/26/2014 07:17 PM, Stephen Warren wrote:
On 08/26/2014 07:12 AM, Tomeu Vizoso wrote:
Sets the EMC clock rate based on the bandwidth requirements registered by
memory clients through the PM_QOS_MEMORY_BANDWIDTH class.

Note: this is just an example and not a proper driver for a external
controller. Its only purpose is to illustrate how such a driver would
set the
frequency of the external memory clock based on the bandwidth
requirements of
memory clients.

diff --git a/arch/arm/mach-tegra/tegra.c b/arch/arm/mach-tegra/tegra.c

@@ -112,6 +117,11 @@ static void __init tegra_dt_init(void)
parent = soc_device_to_device(soc_dev);

+ * HACK: register a platform device to probe the driver
+ */
+ platform_device_register(&tegra_emc);

I don't think this is a hack, except for the bug: That should only
happen on Tegra124 not on all Tegra SoCs.

Do you intend all 3 patches in this series to be merged? You'd mentioned
you didn't when asked about this for a previous version. I'm not sure if
that's changed?

Yeah, I don't want 3/3 merged because we don't have a functional EMC clock yet on T124, and because I don't know yet where will be the best place to have that code in. That depends on Mikko's work on the real EMC driver which is in a bit of flux right now.

I have kept posting it just because I think it complements nicely the explanation in the cover letter, but maybe confuses more than helps.



To merge, I'd need Thierry's ack on patch 2, and Thierry's, Peter's,
Mikko's, and/or Tuomas's on this patch.

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