From mboxrd@z Thu Jan 1 00:00:00 1970 From: vladimir_zapolskiy@mentor.com (Vladimir Zapolskiy) Date: Mon, 21 Sep 2015 17:00:33 +0300 Subject: [PATCH v3 2/2] drm: bridge/dw_hdmi: add dw hdmi i2c bus adapter support In-Reply-To: <20150916221819.GJ21084@n2100.arm.linux.org.uk> References: <1440970470-7155-1-git-send-email-vladimir_zapolskiy@mentor.com> <55F9D7F0.4070402@mentor.com> <20150916221819.GJ21084@n2100.arm.linux.org.uk> Message-ID: <56000D81.9080509@mentor.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 17.09.2015 01:18, Russell King - ARM Linux wrote: > On Wed, Sep 16, 2015 at 02:56:57PM -0700, Doug Anderson wrote: >> Yes, I'd expect 100kHz and 400kHz. >> >> I agree that 50ms is non-trivial, but it's also not something you're >> doing lots of. I'd expect that the EDID is read over this channel at >> cable plugin time and then not used much after that. Adding an extra >> 40ms (10ms vs 50ms) before we can access the TV doesn't seem terrible >> for compatibility. >> >> Doing a quick scan for what others in mainline do: >> >> A few can be found with: >> >> $ git grep -A3 hdmiddc | grep clock-freq >> arch/arm/boot/dts/stihxxx-b2120.dtsi- >> clock-frequency = <100000>; >> arch/arm/boot/dts/tegra30-apalis.dtsi- clock-frequency = <100000>; >> arch/arm/boot/dts/tegra30-beaver.dts- clock-frequency = <100000>; >> arch/arm/boot/dts/tegra30-colibri.dtsi- clock-frequency = <100000>; > > This is a sure way to propagate a bug. > > I said in a previous email that you need to check the HDMI and CEA > specs. I've done this, and HDMI 1.3a specifies a maximum SCL clock > rate of 100kHz. > > So that's settled then. 100kHz is must be. Using 400kHz is out of > specification. > FYI I've managed to measure SCL on iMX6, fast mode stands for 333KHz and standard mode stands for 100KHz, therefore I'll set the latter mode. -- With best wishes, Vladimir From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vladimir Zapolskiy Subject: Re: [PATCH v3 2/2] drm: bridge/dw_hdmi: add dw hdmi i2c bus adapter support Date: Mon, 21 Sep 2015 17:00:33 +0300 Message-ID: <56000D81.9080509@mentor.com> References: <1440970470-7155-1-git-send-email-vladimir_zapolskiy@mentor.com> <55F9D7F0.4070402@mentor.com> <20150916221819.GJ21084@n2100.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from relay1.mentorg.com (relay1.mentorg.com [192.94.38.131]) by gabe.freedesktop.org (Postfix) with ESMTPS id 331536E082 for ; Mon, 21 Sep 2015 07:00:44 -0700 (PDT) In-Reply-To: <20150916221819.GJ21084@n2100.arm.linux.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 , Doug Anderson Cc: Fabio Estevam , "dri-devel@lists.freedesktop.org" , Andy Yan , Thierry Reding , "linux-arm-kernel@lists.infradead.org" List-Id: dri-devel@lists.freedesktop.org T24gMTcuMDkuMjAxNSAwMToxOCwgUnVzc2VsbCBLaW5nIC0gQVJNIExpbnV4IHdyb3RlOgo+IE9u IFdlZCwgU2VwIDE2LCAyMDE1IGF0IDAyOjU2OjU3UE0gLTA3MDAsIERvdWcgQW5kZXJzb24gd3Jv dGU6Cj4+IFllcywgSSdkIGV4cGVjdCAxMDBrSHogYW5kIDQwMGtIei4KPj4KPj4gSSBhZ3JlZSB0 aGF0IDUwbXMgaXMgbm9uLXRyaXZpYWwsIGJ1dCBpdCdzIGFsc28gbm90IHNvbWV0aGluZyB5b3Un cmUKPj4gZG9pbmcgbG90cyBvZi4gIEknZCBleHBlY3QgdGhhdCB0aGUgRURJRCBpcyByZWFkIG92 ZXIgdGhpcyBjaGFubmVsIGF0Cj4+IGNhYmxlIHBsdWdpbiB0aW1lIGFuZCB0aGVuIG5vdCB1c2Vk IG11Y2ggYWZ0ZXIgdGhhdC4gIEFkZGluZyBhbiBleHRyYQo+PiA0MG1zICgxMG1zIHZzIDUwbXMp IGJlZm9yZSB3ZSBjYW4gYWNjZXNzIHRoZSBUViBkb2Vzbid0IHNlZW0gdGVycmlibGUKPj4gZm9y IGNvbXBhdGliaWxpdHkuCj4+Cj4+IERvaW5nIGEgcXVpY2sgc2NhbiBmb3Igd2hhdCBvdGhlcnMg aW4gbWFpbmxpbmUgZG86Cj4+Cj4+IEEgZmV3IGNhbiBiZSBmb3VuZCB3aXRoOgo+Pgo+PiAkIGdp dCBncmVwIC1BMyBoZG1pZGRjIHwgZ3JlcCBjbG9jay1mcmVxCj4+IGFyY2gvYXJtL2Jvb3QvZHRz L3N0aWh4eHgtYjIxMjAuZHRzaS0KPj4gY2xvY2stZnJlcXVlbmN5ID0gPDEwMDAwMD47Cj4+IGFy Y2gvYXJtL2Jvb3QvZHRzL3RlZ3JhMzAtYXBhbGlzLmR0c2ktICAgICAgICAgIGNsb2NrLWZyZXF1 ZW5jeSA9IDwxMDAwMDA+Owo+PiBhcmNoL2FybS9ib290L2R0cy90ZWdyYTMwLWJlYXZlci5kdHMt ICAgICAgICAgICBjbG9jay1mcmVxdWVuY3kgPSA8MTAwMDAwPjsKPj4gYXJjaC9hcm0vYm9vdC9k dHMvdGVncmEzMC1jb2xpYnJpLmR0c2ktICAgICAgICAgY2xvY2stZnJlcXVlbmN5ID0gPDEwMDAw MD47Cj4gCj4gVGhpcyBpcyBhIHN1cmUgd2F5IHRvIHByb3BhZ2F0ZSBhIGJ1Zy4KPiAKPiBJIHNh aWQgaW4gYSBwcmV2aW91cyBlbWFpbCB0aGF0IHlvdSBuZWVkIHRvIGNoZWNrIHRoZSBIRE1JIGFu ZCBDRUEKPiBzcGVjcy4gIEkndmUgZG9uZSB0aGlzLCBhbmQgSERNSSAxLjNhIHNwZWNpZmllcyBh IG1heGltdW0gU0NMIGNsb2NrCj4gcmF0ZSBvZiAxMDBrSHouCj4gCj4gU28gdGhhdCdzIHNldHRs ZWQgdGhlbi4gIDEwMGtIeiBpcyBtdXN0IGJlLiAgVXNpbmcgNDAwa0h6IGlzIG91dCBvZgo+IHNw ZWNpZmljYXRpb24uCj4gCgpGWUkgSSd2ZSBtYW5hZ2VkIHRvIG1lYXN1cmUgU0NMIG9uIGlNWDYs IGZhc3QgbW9kZSBzdGFuZHMgZm9yIDMzM0tIeiBhbmQKc3RhbmRhcmQgbW9kZSBzdGFuZHMgZm9y IDEwMEtIeiwgdGhlcmVmb3JlIEknbGwgc2V0IHRoZSBsYXR0ZXIgbW9kZS4KCi0tCldpdGggYmVz dCB3aXNoZXMsClZsYWRpbWlyCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fCmRyaS1kZXZlbCBtYWlsaW5nIGxpc3QKZHJpLWRldmVsQGxpc3RzLmZyZWVkZXNr dG9wLm9yZwpodHRwOi8vbGlzdHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8vZHJp LWRldmVsCg==