[PATCH v7 phy-next 09/27] scsi: ufs: exynos: stop poking into struct phy guts

[Vladimir Oltean]

Sashiko says:
> commit 76ded6c0290bdb192c2ae1af9a2e6a47fc39c9a1
> Author: Vladimir Oltean <vladimir.oltean at nxp.com>
> 
> scsi: ufs: exynos: stop poking into struct phy guts
> This commit modifies the Exynos UFS driver to stop directly accessing the
> generic PHY's power_count. Instead, it tracks the PHY power state internally
> using a new phy_powered_on flag to properly handle link retries and
> suspend/resume operations.
> 
> > diff --git a/drivers/ufs/host/ufs-exynos.c b/drivers/ufs/host/ufs-exynos.c
> > --- a/drivers/ufs/host/ufs-exynos.c
> > +++ b/drivers/ufs/host/ufs-exynos.c
> [ ... ]
> > @@ -1513,6 +1516,9 @@ static void exynos_ufs_exit(struct ufs_hba *hba)
> >  {
> >  	struct exynos_ufs *ufs = ufshcd_get_variant(hba);
> >
> > +	if (!ufs->phy_powered_on)
> > +		return;
> > +
> >  	phy_power_off(ufs->phy);
> >  	phy_exit(ufs->phy);
> >  }
> 
> Does this introduce a regression where initialization resources are leaked
> if the driver is unbound while suspended?
> Looking at exynos_ufs_suspend(), the PHY is powered off and phy_powered_on
> is set to false, but phy_exit() is intentionally not called so the PHY
> remains initialized:
> exynos_ufs_suspend()
>         if (!ufshcd_is_link_active(hba) && ufs->phy_powered_on) {
>                 phy_power_off(ufs->phy);
>                 ufs->phy_powered_on = false;
>         }
> If an unbind or fatal error occurs while in this suspended state,
> exynos_ufs_exit() will see phy_powered_on as false and return immediately.
> The initialization reference and any resources allocated by phy_init()
> would never be released since phy_exit() is completely skipped.
> [ ... ]

I think I've been looking at this issue all wrong, not considering why
the UFS HCD driver calls phy_exit() -> phy_init() at runtime and what
can be done about that.

I have replaced this patch with the one attached, which I will be sending
for v8.
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