From mboxrd@z Thu Jan 1 00:00:00 1970 From: dianders@chromium.org (Doug Anderson) Date: Wed, 2 Sep 2015 17:22:59 -0700 Subject: [PATCH] ARM: dts: Add ddc i2c reference to veyron In-Reply-To: References: <1441229148-12095-1-git-send-email-dianders@chromium.org> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Rob, On Wed, Sep 2, 2015 at 5:13 PM, Rob Herring wrote: > On Wed, Sep 2, 2015 at 4:25 PM, Douglas Anderson wrote: >> The ddc-i2c-bus property was missing from the veyron dtsi file since >> downstream the ddc-i2c-bus was still being specified in rk3288.dtsi and >> nobody noticed when the veyron dtsi was sent upstream. Add it. >> >> Signed-off-by: Douglas Anderson >> --- >> Note: I noticed that this was wrong but I don't currently have >> graphics up and running on upstream on veyron. Posting this anyway >> since it's pretty clear that it's needed. If someone else wants to >> try it out that'd be nice, otherwise I'll put it on my list to figure >> out how to get myself setup for graphics upstream. ;) > > Based on your other patch, this is temporary, right? Yes, though since I'm not personally working on the other patch series upstream I can't say for how long the "temporary" is.. I mostly posted the 2nd patch because it was clearly correct to add some pinmuxing states and could land any time, so I thought I'd be helpful. You're right that in the Chrome OS tree I turned right around and effectively removed the "ddc-i2c-bus", but having it land first adds a much better logical progression (make it the same as everyone else and _then_ change it). It also provides a revert path if something goes wrong. :) > I've been looking at DRM a lot lately. I think specifying the i2c bus > in the hdmi chip or IP block node is wrong. If the I2C host is > separate from the HDMI block, then it's only connection is to the HDMI > connector. So the I2C host to the connector relationship is what the > DT should describe. HPD gpio is similar. Now if the HDMI bridge > controls DDC and HPD directly, then we don't need to describe those > connections. I will say that I know very very little about DRM. Mostly I just visit it when there's some bug I'm running into that I can't find a better suited owner for. ;) I'm not sure I followed your whole paragraph. Could you give a fragment of DTS for how you'd imagine this ought to work? Also: the patch I submitted does match the current bindings if I understand it right. ...as is typical with device tree, if we want to change the bindings we've got to have a really good reason because we'd either need to figure out how to deal with existing DTBs in the field that need to run with newer kernels (if those exist). -Doug