From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shawn Lin Subject: Re: [PATCH 2/2] phy: rockchip-emmc: try to get drive impedance from DT Date: Fri, 6 Jan 2017 09:09:53 +0800 Message-ID: <669c85b1-f0fb-c58e-90a8-3aeac3118656@rock-chips.com> References: <1483608682-226716-1-git-send-email-shawn.lin@rock-chips.com> <1483608682-226716-2-git-send-email-shawn.lin@rock-chips.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Doug Anderson Cc: shawn.lin-TNX95d0MmH7DzftRWevZcw@public.gmane.org, Kishon Vijay Abraham I , Rob Herring , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "open list:ARM/Rockchip SoC..." , Heiko Stuebner , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: devicetree@vger.kernel.org On 2017/1/6 8:51, Doug Anderson wrote: > Hi, > > On Thu, Jan 5, 2017 at 1:31 AM, Shawn Lin wrote: >> Try to get drive impedance from DT and use it, otherwise >> use 50ohm by default in order not to break the existing boards >> as 50ohm works fine for them already. >> >> Signed-off-by: Shawn Lin >> --- >> >> drivers/phy/phy-rockchip-emmc.c | 29 ++++++++++++++++++++++++++++- >> 1 file changed, 28 insertions(+), 1 deletion(-) > > I could have sworn that you somehow needed to make sure that the eMMC > part itself needed to also be updated to be told the matching drive > impedance so you don't get a mismatch. How do you make that work? No I didn't. So that means the eMMC part itself still couldn't be updated. The intention for me to introduce this only for emmc phy is that I got report that the default drive impedance of one eMMC is not 50ohms, so now we haven't been able to update it for eMMC part but maybe we could just update it for the phy itself to match them in between. > ...or am I just confused. I meant to try to dig more, but ran out of > time today. :( > > -Doug > > > -- Best Regards Shawn Lin -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html