Re: [PATCH] ata: ahci-platform: add reset control support

From: Thierry Reding
Date: Thu Apr 05 2018 - 05:54:51 EST


On Fri, Mar 23, 2018 at 10:30:53AM +0900, Kunihiko Hayashi wrote:
> Add support to get and control a list of resets for the device
> as optional and shared. These resets must be kept de-asserted until
> the device is enabled.
>
> This is specified as shared because some SoCs like UniPhier series
> have common reset controls with all ahci controller instances.
>
> Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx>
> ---
> .../devicetree/bindings/ata/ahci-platform.txt | 1 +
> drivers/ata/ahci.h | 1 +
> drivers/ata/libahci_platform.c | 24 +++++++++++++++++++---
> 3 files changed, 23 insertions(+), 3 deletions(-)

This causes a regression on Tegra because we explicitly request the
resets after the call to ahci_platform_get_resources().

From a quick look, ahci_mtk and ahci_st are in the same boat, adding the
corresponding maintainers to Cc.

Patrice, Matthias: does SATA still work for you after this patch? This
has been in linux-next since next-20180327.

Given how this is one of the more hardware-specific bits, perhaps a
better way to do this is to move reset handling into a Uniphier driver
much like Tegra, Mediatek and ST?

That said, I don't see SATA support for any of the Socionext hardware
either in the DT bindings or drivers/ata, so perhaps it'd be best to
back this out again until we have something that's more well tested?

Thierry

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