Re: [PATCH v2 2/3] ata: libahci_platform: add reset control support

From: Rob Herring
Date: Tue Aug 28 2018 - 20:34:23 EST


On Wed, Aug 22, 2018 at 09:13:02PM +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.
>
> However, according to Thierry's view,
> https://www.spinics.net/lists/linux-ide/msg55357.html
> some hardware-specific drivers already use their own resets,
> and the common reset make a path to occur double controls of resets.
>
> The ahci_platform_get_resources() can get and control the reset
> only when the second argument includes AHCI_PLATFORM_GET_RESETS bit.
>
> Suggested-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> Cc: Thierry Reding <thierry.reding@xxxxxxxxx>
> Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx>
> ---
> .../devicetree/bindings/ata/ahci-platform.txt | 1 +

Acked-by: Rob Herring <robh@xxxxxxxxxx>

> drivers/ata/ahci.h | 1 +
> drivers/ata/libahci_platform.c | 31 ++++++++++++++++++----
> include/linux/ahci_platform.h | 2 ++
> 4 files changed, 30 insertions(+), 5 deletions(-)