From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Subject: Re: [PATCH RESEND v2 08/12] dt-bindings: add binding for generic eDP panel Date: Mon, 4 Feb 2019 10:39:08 -0600 Message-ID: References: <20190203185501.8958-1-anarsoul@gmail.com> <20190203185501.8958-9-anarsoul@gmail.com> <20190204074350.GC16448@ulmo> <20190204082353.GE19087@ulmo> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Vasily Khoruzhick Cc: Mark Rutland , devicetree , David Airlie , linux-sunxi , dri-devel , Maxime Ripard , Chen-Yu Tsai , Thierry Reding , Sean Paul , Laurent Pinchart , arm-linux , Icenowy Zheng List-Id: devicetree@vger.kernel.org T24gTW9uLCBGZWIgNCwgMjAxOSBhdCAxMDoxMSBBTSBWYXNpbHkgS2hvcnV6aGljayA8YW5hcnNv dWxAZ21haWwuY29tPiB3cm90ZToKPgo+IE9uIE1vbiwgRmViIDQsIDIwMTkgYXQgMTI6MjQgQU0g VGhpZXJyeSBSZWRpbmcgPHRoaWVycnkucmVkaW5nQGdtYWlsLmNvbT4gd3JvdGU6Cj4gPiA+Cj4g PiA+IFBpbmVib29rIHVzZWQgc2V2ZXJhbCA3NjhwIHBhbmVscyB0aGF0IGhhdmUgc2xpZ2h0bHkg ZGlmZmVyZW50IHRpbWluZ3MKPiA+ID4gYW5kIHJlY2VudCBiYXRjaCB1c2VzIDEwODBwIHBhbmVs Lgo+ID4gPgo+ID4gPiBXaGF0IHBhbmVsIGRlc2NyaXB0b3Igc2hvdWxkIEkgdXNlIGFzIGZhbGxi YWNrPwo+ID4KPiA+IFlvdSBkb24ndCB1c2UgcGFuZWwgZGVzY3JpcHRvcnMgYXMgZmFsbGJhY2su IFRoZSBzaW1wbGUtcGFuZWwgZHJpdmVyCj4gPiB3aWxsIGJpbmQgdG8gYSBwYW5lbCBkZXZpY2Ug YW5kIHVzZSB0aGUgY29ycmVzcG9uZGluZyBkZXNjcmlwdG9yLiBJZgo+ID4geW91ciBkZXZpY2Ug dHJlZSBjb250YWlucyB0aGUgY29ycmVjdCBpbmZvcm1hdGlvbiwgdGhlIGRlc2NyaXB0b3IgaXMK PiA+IGNvcnJlY3QgZm9yIHRoZSBwYW5lbCB5b3UgaGF2ZS4KPiA+Cj4gPiBJbiBvdGhlciB3b3Jk cyB5b3UgbmVlZCB0byBlbnN1cmUgdGhhdCB5b3UgaGF2ZSB0aGUgY29ycmVjdCBwYW5lbCBpbgo+ ID4gZGV2aWNlIHRyZWUgZm9yIHRoZSBib2FyZCB0aGF0IHlvdSdyZSB1c2luZy4gVGhpcyBpcyBl eGFjdGx5IHRoZSBzYW1lCj4gPiB0aGluZyBhcyBmb3Igb3RoZXIgZGV2aWNlcy4KPiA+Cj4gPiBP bmUgd2F5IHRvIHRvIHRoaXMgaXMgdG8gaGF2ZSBzZXBhcmF0ZSBkZXZpY2UgdHJlZXMgZm9yIGVh Y2ggdmFyaWFudAo+ID4gb2YgdGhlIGJvYXJkIHRoYXQgeW91IHdhbnQgdG8gc3VwcG9ydC4gQW5v dGhlciB2YXJpYW50IG1heSBiZSB0byBoYXZlCj4gPiBhIGNvbW1vbiBkZXZpY2UgdHJlZSBhbmQg dGhlbiBoYXZlIHNvbWUgZWFybHkgZmlybXdhcmUgdXBkYXRlIHRoZSBEVEIKPiA+IHdpdGggdGhl IGNvcnJlY3QgcGFuZWwgaW5mb3JtYXRpb24uCj4KPiBUaGF0IGRlZmVhdHMgdGhlIHB1cnBvc2Ug b2YgdXNpbmcgZURQIHBhbmVscy4gUGFuZWwgY2FuIGlkZW50aWZ5Cj4gaXRzZWxmIGFuZCByZXBv cnQgd2hhdCB0aW1pbmdzIGl0IHN1cHBvcnRzLgoKSWYgeW91IGFyZSBjb25maWRlbnQgdGhhdCB0 aGlzIHdvcmtzIGZvciBhbGwgcGFuZWxzLCB0aGVuIHRoZSBmaXJtd2FyZQpjYW4gaWRlbnRpZnkg dGhlIHJpZ2h0IHBhbmVsIGFuZCB1cGRhdGUgdGhlIERUQiB3aXRoIHRoZSBjb3JyZWN0CmluZm9y bWF0aW9uLiBJZiB0aGlzIGRvZXNuJ3Qgd29yayBpbiB0aGUgZmlybXdhcmUsIHRoZW4gaXQgaXMg bm90CmdvaW5nIHRvIHdvcmsgaW4gdGhlIGtlcm5lbCBlaXRoZXIgYW5kIHlvdSBhcmUgU09MIHdp dGhvdXQgc3BlY2lmaWMKcGFuZWwgaW5mb3JtYXRpb24gaW4gdGhlIERULgoKPiBJZiB3ZSB1c2Ug c2VwYXJhdGUgRFRCcyB0aGVuIHVzZXJzIHdpbGwgaGF2ZSB0byBmaWd1cmUgb3V0IHdoYXQgcGFu ZWwKPiBpcyBpbnN0YWxsZWQgaW4gdGhlaXIgaGFyZHdhcmUgYW5kIHVzZSBhcHByb3ByaWF0ZSBz b2Z0d2FyZSBpbWFnZSAtCj4gdGhhdCdzIHNvbWV0aGluZyBJJ2QgbGlrZSB0byBhdm9pZC4KCkkg dGhpbmsgVGhpZXJyeSBtZWFudCBlaXRoZXIgd2F5IHRoaXMgaXMgYSBmaXJtd2FyZSBwcm9ibGVt LiBJZiB5b3UKaGF2ZSBhIFNLVSBwZXIgZGV2aWNlIGFuZCBwYW5lbCB0eXBlLCB0aGVuIHRoZSBm aXJtd2FyZSBqdXN0IHBpY2tzIGEKZHRiIGFtb25nIGEgc2V0LgoKUm9iCl9fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fCmRyaS1kZXZlbCBtYWlsaW5nIGxpc3QK ZHJpLWRldmVsQGxpc3RzLmZyZWVkZXNrdG9wLm9yZwpodHRwczovL2xpc3RzLmZyZWVkZXNrdG9w Lm9yZy9tYWlsbWFuL2xpc3RpbmZvL2RyaS1kZXZlbAo= From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CC217C282C4 for ; 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Mon, 04 Feb 2019 08:39:19 -0800 (PST) MIME-Version: 1.0 References: <20190203185501.8958-1-anarsoul@gmail.com> <20190203185501.8958-9-anarsoul@gmail.com> <20190204074350.GC16448@ulmo> <20190204082353.GE19087@ulmo> In-Reply-To: From: Rob Herring Date: Mon, 4 Feb 2019 10:39:08 -0600 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH RESEND v2 08/12] dt-bindings: add binding for generic eDP panel To: Vasily Khoruzhick X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190204_083921_105642_081A0B11 X-CRM114-Status: GOOD ( 20.83 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , devicetree , Archit Taneja , Andrzej Hajda , David Airlie , linux-sunxi , dri-devel , Maxime Ripard , Chen-Yu Tsai , Thierry Reding , Sean Paul , Laurent Pinchart , Daniel Vetter , arm-linux , Icenowy Zheng Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Feb 4, 2019 at 10:11 AM Vasily Khoruzhick wrote: > > On Mon, Feb 4, 2019 at 12:24 AM Thierry Reding wrote: > > > > > > Pinebook used several 768p panels that have slightly different timings > > > and recent batch uses 1080p panel. > > > > > > What panel descriptor should I use as fallback? > > > > You don't use panel descriptors as fallback. The simple-panel driver > > will bind to a panel device and use the corresponding descriptor. If > > your device tree contains the correct information, the descriptor is > > correct for the panel you have. > > > > In other words you need to ensure that you have the correct panel in > > device tree for the board that you're using. This is exactly the same > > thing as for other devices. > > > > One way to to this is to have separate device trees for each variant > > of the board that you want to support. Another variant may be to have > > a common device tree and then have some early firmware update the DTB > > with the correct panel information. > > That defeats the purpose of using eDP panels. Panel can identify > itself and report what timings it supports. If you are confident that this works for all panels, then the firmware can identify the right panel and update the DTB with the correct information. If this doesn't work in the firmware, then it is not going to work in the kernel either and you are SOL without specific panel information in the DT. > If we use separate DTBs then users will have to figure out what panel > is installed in their hardware and use appropriate software image - > that's something I'd like to avoid. I think Thierry meant either way this is a firmware problem. If you have a SKU per device and panel type, then the firmware just picks a dtb among a set. Rob _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel