From mboxrd@z Thu Jan 1 00:00:00 1970 From: shawn.guo@freescale.com (Shawn Guo) Date: Sat, 17 May 2014 22:05:26 +0800 Subject: [PATCH] ahci: imx: PLL clock needs 100us to settle down In-Reply-To: References: <1400330761-2432-1-git-send-email-shawn.guo@freescale.com> Message-ID: <20140517140525.GE10685@dragon> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Sat, May 17, 2014 at 10:58:20AM -0300, Fabio Estevam wrote: > On Sat, May 17, 2014 at 9:46 AM, Shawn Guo 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 > > On my sabresd board that was not connected to any sata disk I was > always getting the 'failed to reset phy' error. Damn. I never noticed that the error is even there when no SATA disk is attached. Sorry. > > With this patch the error goes away and the driver probes successfully. > > Tested-by: Fabio Estevam Thanks. Shawn