[PATCH] ahci: imx: PLL clock needs 100us to settle down

[Fabio Estevam]

On Sat, May 17, 2014 at 9:46 AM, Shawn Guo <shawn.guo at freescale.com> wrote:
> The commit e783c51 (ahci: imx: software workaround for phy reset issue
> in resume) calls imx_sata_phy_reset() to reset phy immediately after
> SATA MPLL is enabled.  It seems working fine mostly, but fails in some
> case as below.
>
> ...
> ahci-imx 2200000.sata: failed to reset phy: -110
> ahci-imx: probe of 2200000.sata failed with error -110
>
> After talking to the designer, we learnt that when enabling i.MX6Q SATA
> MPLL, we need to wait 100us for it to settle down for safety.  Add this
> required delay to fix above failure.
>
> Signed-off-by: Shawn Guo <shawn.guo at freescale.com>

On my sabresd board that was not connected to any sata disk I was
always getting the 'failed to reset phy' error.

With this patch the error goes away and the driver probes successfully.

Tested-by: Fabio Estevam <fabio.estevam at freescale.com>