From mboxrd@z Thu Jan 1 00:00:00 1970 From: tj@kernel.org (Tejun Heo) Date: Mon, 19 May 2014 16:09:00 -0400 Subject: [PATCH] ahci: imx: PLL clock needs 100us to settle down In-Reply-To: <1400330761-2432-1-git-send-email-shawn.guo@freescale.com> References: <1400330761-2432-1-git-send-email-shawn.guo@freescale.com> Message-ID: <20140519200900.GB27506@mtj.dyndns.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Sat, May 17, 2014 at 08:46:01PM +0800, 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 Applied to libata/for-3.15-fixes. Thanks. -- tejun