Re: [PATCH v2 1/6] ata: libahci_platform: comply to PHY framework

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 30-11-18 16:38, Miquel Raynal wrote:
> Current implementation of the libahci does not take into account the
> new PHY framework. Correct the situation by adding a call to
> phy_set_mode() before phy_power_on() and by adding calls to
> ahci_platform_enable/disable_phys() at suspend/resume_host() time.
> 
> Suggested-by: Grzegorz Jaszczyk <jaz@semihalf.com>
> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

Much better. Some remarks inline.

> ---
>   drivers/ata/ahci.h             |  2 ++
>   drivers/ata/libahci_platform.c | 19 ++++++++++++++++++-
>   2 files changed, 20 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
> index ef356e70e6de..982638b37fee 100644
> --- a/drivers/ata/ahci.h
> +++ b/drivers/ata/ahci.h
> @@ -254,6 +254,8 @@ enum {
>   	AHCI_HFLAG_IS_MOBILE		= (1 << 25), /* mobile chipset, use
>   							SATA_MOBILE_LPM_POLICY
>   							as default lpm_policy */
> +	AHCI_HFLAG_MANAGE_PHYS		= (1 << 26), /* let the core manage the
> +							PHYs when relevant */

Using a hflag for this is a good idea, but the MANAGE_PHYS names is a bit
generic, even if this is not set then ahci_platform_enable_resources() will
still enable the phy. So I would name this AHCI_HFLAG_SUSPEND_PHYS to make
clear this only influences suspend/resume behavior.

Also see below.

>   	/* ap->flags bits */
>   
> diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c
> index 4b900fc659f7..f5a64eb1fea8 100644
> --- a/drivers/ata/libahci_platform.c
> +++ b/drivers/ata/libahci_platform.c
> @@ -56,6 +56,12 @@ static int ahci_platform_enable_phys(struct ahci_host_priv *hpriv)
>   		if (rc)
>   			goto disable_phys;
>   
> +		rc = phy_set_mode(hpriv->phys[i], PHY_MODE_SATA);
> +		if (rc) {
> +			phy_exit(hpriv->phys[i]);
> +			goto disable_phys;
> +		}
> +
>   		rc = phy_power_on(hpriv->phys[i]);
>   		if (rc) {
>   			phy_exit(hpriv->phys[i]);
> @@ -378,7 +384,8 @@ static int ahci_platform_get_regulator(struct ahci_host_priv *hpriv, u32 port,
>    * 3) 0 - AHCI_MAX_CLKS clocks, as specified in the devs devicetree node,
>    *    or for non devicetree enabled platforms a single clock
>    * 4) resets, if flags has AHCI_PLATFORM_GET_RESETS (optional)
> - * 5) phys (optional)
> + * 5) phys (optional), PHY handling during suspend/resume will be skipped if the
> + *    flag AHCI_HFLAG_MANAGE_PHYS is missing.
>    *
>    * RETURNS:
>    * The allocated ahci_host_priv on success, otherwise an ERR_PTR value
> @@ -458,6 +465,9 @@ struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev,
>   		}
>   	}
>   
> +	if (flags & AHCI_HFLAG_MANAGE_PHYS)
> +		hpriv->flags |= AHCI_HFLAG_MANAGE_PHYS;
> +
>   	hpriv->nports = child_nodes = of_get_child_count(dev->of_node);
>   
>   	/*

Interpreting a flag passed to ahci_platform_get_resources using a
AHCI_HFLAG_* mask is asking for trouble in the future.

Since you are using a hflag for this, you can just drop this chunk / change
and in the caller of ahci_platform_get_resources() do:

	hpriv = ahci_platform_get_resources(pdev, ...);
	if (IS_ERR(hpriv))
		...

	hpriv->flags |= AHCI_HFLAG_MANAGE_PHYS;

Settting hflags like this after calling ahci_platform_get_resources()
is already done in several place.

Once this is changed, this patch looks good to go upstream to me.

Regards,

Hans




> @@ -738,6 +748,9 @@ int ahci_platform_suspend_host(struct device *dev)
>   	writel(ctl, mmio + HOST_CTL);
>   	readl(mmio + HOST_CTL); /* flush */
>   
> +	if (hpriv->flags & AHCI_HFLAG_MANAGE_PHYS)
> +		ahci_platform_disable_phys(hpriv);
> +
>   	return ata_host_suspend(host, PMSG_SUSPEND);
>   }
>   EXPORT_SYMBOL_GPL(ahci_platform_suspend_host);
> @@ -756,6 +769,7 @@ EXPORT_SYMBOL_GPL(ahci_platform_suspend_host);
>   int ahci_platform_resume_host(struct device *dev)
>   {
>   	struct ata_host *host = dev_get_drvdata(dev);
> +	struct ahci_host_priv *hpriv = host->private_data;
>   	int rc;
>   
>   	if (dev->power.power_state.event == PM_EVENT_SUSPEND) {
> @@ -766,6 +780,9 @@ int ahci_platform_resume_host(struct device *dev)
>   		ahci_init_controller(host);
>   	}
>   
> +	if (hpriv->flags & AHCI_HFLAG_MANAGE_PHYS)
> +		ahci_platform_enable_phys(hpriv);
> +
>   	ata_host_resume(host);
>   
>   	return 0;
>