From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: From: Laurent Pinchart To: Russell King - ARM Linux Cc: Laurent Pinchart , dri-devel@lists.freedesktop.org, Andy Yan , Archit Taneja , Fabio Estevam , Heiko Stuebner , Jose Abreu , Kieran Bingham , Mark Yao , Philipp Zabel , Ulrich Hecht , Vladimir Zapolskiy , linux-renesas-soc@vger.kernel.org Subject: Re: [PATCH 13/22] drm: bridge: dw-hdmi: Replace device type with platform quirks Date: Fri, 02 Dec 2016 18:45:46 +0200 Message-ID: <1898458.1NNH7zlFYO@avalon> In-Reply-To: <20161202160817.GE14217@n2100.armlinux.org.uk> References: <1480635817-1258-1-git-send-email-laurent.pinchart+renesas@ideasonboard.com> <4921806.T6YjZHsEAd@avalon> <20161202160817.GE14217@n2100.armlinux.org.uk> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" List-ID: Hi Russell, On Friday 02 Dec 2016 16:08:17 Russell King - ARM Linux wrote: > On Fri, Dec 02, 2016 at 05:43:43PM +0200, Laurent Pinchart wrote: > > DW_HDMI_QUIRK_FC_INVIDCONF is indeed a bad name, I'll fix that. > > > > Do you know why this function needs to write to the HDMI_FC_INVIDCONF > > register four times in the normal case, and once only for IMX6DL ? > > (I don't have much time at present, I'm buried in ARM64 crud trying to > get a platform to boot, and working out how to debug an ARM64 platform > that even earlycon doesn't work on... no printascii() types of easy > debug facilities on ARM64 make this job several orders of magnitude > harder than it needs to be...) Thanks all the more for taking time to reply. > It prevents a magenta line down the left hand side of the screen, which > is caused when the frame composer in the HDMI Tx gets confused - > according to the errata, it does a load of maths when you write to the > frame composer registers, and sometimes it doesn't update properly. > > So, the four writes (and the number is critical) is there to persuade > the IP to do the maths with the right values so the internal timings > are correct. > > The rather confusing thing is - it's actually IMX6Q which has the more > severe errata, not IMX6DL - the workaround of four writes is applied > in the 6Q case. > > It's covered by ERR004308 in the IMX6Q Errata document (search for > IMX6DQCE). It isn't mentioned in the IMX6DL documentation, but it > seems that similar workaround of one write is necessary there. > > Some of this was determined by experimentation in conjunction with the > errata documentation - I remember it took a while to get it right so > that we didn't ever see the magenta line. That's interesting. I'll test the different options on my Renesas platform (no write, one write, four writes) and see what is needed. Could anyone perform the same tests on a Rockchip RK3288 system ? -- Regards, Laurent Pinchart From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurent Pinchart Subject: Re: [PATCH 13/22] drm: bridge: dw-hdmi: Replace device type with platform quirks Date: Fri, 02 Dec 2016 18:45:46 +0200 Message-ID: <1898458.1NNH7zlFYO@avalon> References: <1480635817-1258-1-git-send-email-laurent.pinchart+renesas@ideasonboard.com> <4921806.T6YjZHsEAd@avalon> <20161202160817.GE14217@n2100.armlinux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from galahad.ideasonboard.com (galahad.ideasonboard.com [185.26.127.97]) by gabe.freedesktop.org (Postfix) with ESMTPS id 92DD46E98A for ; Fri, 2 Dec 2016 16:45:30 +0000 (UTC) In-Reply-To: <20161202160817.GE14217@n2100.armlinux.org.uk> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Russell King - ARM Linux Cc: Fabio Estevam , Jose Abreu , Laurent Pinchart , Ulrich Hecht , Kieran Bingham , dri-devel@lists.freedesktop.org, linux-renesas-soc@vger.kernel.org, Andy Yan , Vladimir Zapolskiy List-Id: dri-devel@lists.freedesktop.org SGkgUnVzc2VsbCwKCk9uIEZyaWRheSAwMiBEZWMgMjAxNiAxNjowODoxNyBSdXNzZWxsIEtpbmcg LSBBUk0gTGludXggd3JvdGU6Cj4gT24gRnJpLCBEZWMgMDIsIDIwMTYgYXQgMDU6NDM6NDNQTSAr MDIwMCwgTGF1cmVudCBQaW5jaGFydCB3cm90ZToKPiA+IERXX0hETUlfUVVJUktfRkNfSU5WSURD T05GIGlzIGluZGVlZCBhIGJhZCBuYW1lLCBJJ2xsIGZpeCB0aGF0Lgo+ID4gCj4gPiBEbyB5b3Ug a25vdyB3aHkgdGhpcyBmdW5jdGlvbiBuZWVkcyB0byB3cml0ZSB0byB0aGUgSERNSV9GQ19JTlZJ RENPTkYKPiA+IHJlZ2lzdGVyICBmb3VyIHRpbWVzIGluIHRoZSBub3JtYWwgY2FzZSwgYW5kIG9u Y2Ugb25seSBmb3IgSU1YNkRMID8KPiAKPiAoSSBkb24ndCBoYXZlIG11Y2ggdGltZSBhdCBwcmVz ZW50LCBJJ20gYnVyaWVkIGluIEFSTTY0IGNydWQgdHJ5aW5nIHRvCj4gZ2V0IGEgcGxhdGZvcm0g dG8gYm9vdCwgYW5kIHdvcmtpbmcgb3V0IGhvdyB0byBkZWJ1ZyBhbiBBUk02NCBwbGF0Zm9ybQo+ IHRoYXQgZXZlbiBlYXJseWNvbiBkb2Vzbid0IHdvcmsgb24uLi4gbm8gcHJpbnRhc2NpaSgpIHR5 cGVzIG9mIGVhc3kKPiBkZWJ1ZyBmYWNpbGl0aWVzIG9uIEFSTTY0IG1ha2UgdGhpcyBqb2Igc2V2 ZXJhbCBvcmRlcnMgb2YgbWFnbml0dWRlCj4gaGFyZGVyIHRoYW4gaXQgbmVlZHMgdG8gYmUuLi4p CgpUaGFua3MgYWxsIHRoZSBtb3JlIGZvciB0YWtpbmcgdGltZSB0byByZXBseS4KCj4gSXQgcHJl dmVudHMgYSBtYWdlbnRhIGxpbmUgZG93biB0aGUgbGVmdCBoYW5kIHNpZGUgb2YgdGhlIHNjcmVl biwgd2hpY2gKPiBpcyBjYXVzZWQgd2hlbiB0aGUgZnJhbWUgY29tcG9zZXIgaW4gdGhlIEhETUkg VHggZ2V0cyBjb25mdXNlZCAtCj4gYWNjb3JkaW5nIHRvIHRoZSBlcnJhdGEsIGl0IGRvZXMgYSBs b2FkIG9mIG1hdGhzIHdoZW4geW91IHdyaXRlIHRvIHRoZQo+IGZyYW1lIGNvbXBvc2VyIHJlZ2lz dGVycywgYW5kIHNvbWV0aW1lcyBpdCBkb2Vzbid0IHVwZGF0ZSBwcm9wZXJseS4KPiAKPiBTbywg dGhlIGZvdXIgd3JpdGVzIChhbmQgdGhlIG51bWJlciBpcyBjcml0aWNhbCkgaXMgdGhlcmUgdG8g cGVyc3VhZGUKPiB0aGUgSVAgdG8gZG8gdGhlIG1hdGhzIHdpdGggdGhlIHJpZ2h0IHZhbHVlcyBz byB0aGUgaW50ZXJuYWwgdGltaW5ncwo+IGFyZSBjb3JyZWN0Lgo+IAo+IFRoZSByYXRoZXIgY29u ZnVzaW5nIHRoaW5nIGlzIC0gaXQncyBhY3R1YWxseSBJTVg2USB3aGljaCBoYXMgdGhlIG1vcmUK PiBzZXZlcmUgZXJyYXRhLCBub3QgSU1YNkRMIC0gdGhlIHdvcmthcm91bmQgb2YgZm91ciB3cml0 ZXMgaXMgYXBwbGllZAo+IGluIHRoZSA2USBjYXNlLgo+IAo+IEl0J3MgY292ZXJlZCBieSBFUlIw MDQzMDggaW4gdGhlIElNWDZRIEVycmF0YSBkb2N1bWVudCAoc2VhcmNoIGZvcgo+IElNWDZEUUNF KS4gIEl0IGlzbid0IG1lbnRpb25lZCBpbiB0aGUgSU1YNkRMIGRvY3VtZW50YXRpb24sIGJ1dCBp dAo+IHNlZW1zIHRoYXQgc2ltaWxhciB3b3JrYXJvdW5kIG9mIG9uZSB3cml0ZSBpcyBuZWNlc3Nh cnkgdGhlcmUuCj4gCj4gU29tZSBvZiB0aGlzIHdhcyBkZXRlcm1pbmVkIGJ5IGV4cGVyaW1lbnRh dGlvbiBpbiBjb25qdW5jdGlvbiB3aXRoIHRoZQo+IGVycmF0YSBkb2N1bWVudGF0aW9uIC0gSSBy ZW1lbWJlciBpdCB0b29rIGEgd2hpbGUgdG8gZ2V0IGl0IHJpZ2h0IHNvCj4gdGhhdCB3ZSBkaWRu J3QgZXZlciBzZWUgdGhlIG1hZ2VudGEgbGluZS4KClRoYXQncyBpbnRlcmVzdGluZy4gSSdsbCB0 ZXN0IHRoZSBkaWZmZXJlbnQgb3B0aW9ucyBvbiBteSBSZW5lc2FzIHBsYXRmb3JtIChubyAKd3Jp dGUsIG9uZSB3cml0ZSwgZm91ciB3cml0ZXMpIGFuZCBzZWUgd2hhdCBpcyBuZWVkZWQuIENvdWxk IGFueW9uZSBwZXJmb3JtIAp0aGUgc2FtZSB0ZXN0cyBvbiBhIFJvY2tjaGlwIFJLMzI4OCBzeXN0 ZW0gPwoKLS0gClJlZ2FyZHMsCgpMYXVyZW50IFBpbmNoYXJ0CgpfX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fXwpkcmktZGV2ZWwgbWFpbGluZyBsaXN0CmRyaS1k ZXZlbEBsaXN0cy5mcmVlZGVza3RvcC5vcmcKaHR0cHM6Ly9saXN0cy5mcmVlZGVza3RvcC5vcmcv bWFpbG1hbi9saXN0aW5mby9kcmktZGV2ZWwK