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
memory
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.

Regards,

Tomeu

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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