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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 31696C43603 for ; Wed, 4 Dec 2019 18:27:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0636920661 for ; Wed, 4 Dec 2019 18:27:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="SbzuqJJ3" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729292AbfLDS10 (ORCPT ); Wed, 4 Dec 2019 13:27:26 -0500 Received: from lelv0143.ext.ti.com ([198.47.23.248]:56970 "EHLO lelv0143.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729423AbfLDS1V (ORCPT ); Wed, 4 Dec 2019 13:27:21 -0500 Received: from lelv0265.itg.ti.com ([10.180.67.224]) by lelv0143.ext.ti.com (8.15.2/8.15.2) with ESMTP id xB4IR9uL118997; Wed, 4 Dec 2019 12:27:09 -0600 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1575484029; bh=Uet6ftlBWt6BLt4lGobOQD5+cFdGEWSfTiuKL7t91js=; h=Subject:To:CC:References:From:Date:In-Reply-To; b=SbzuqJJ3+pluoOby71dsCavu5VY1IJbySeO+FHIVH2JAUN6StofHWG/cC1GLh6F17 LDw6r7+PbTZtCvHUaRrRIxN8e7jV2AdctsNbU4vKyqu7FaEfhAMgi5d53K/QIjCtlc q58YXAV6zNHqrtQk9b87TGsUYr4gve4UuoeudWu4= Received: from DLEE109.ent.ti.com (dlee109.ent.ti.com [157.170.170.41]) by lelv0265.itg.ti.com (8.15.2/8.15.2) with ESMTPS id xB4IR9Tb051413 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 4 Dec 2019 12:27:09 -0600 Received: from DLEE115.ent.ti.com (157.170.170.26) by DLEE109.ent.ti.com (157.170.170.41) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1847.3; Wed, 4 Dec 2019 12:27:07 -0600 Received: from lelv0327.itg.ti.com (10.180.67.183) by DLEE115.ent.ti.com (157.170.170.26) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1847.3 via Frontend Transport; Wed, 4 Dec 2019 12:27:07 -0600 Received: from [192.168.2.6] (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0327.itg.ti.com (8.15.2/8.15.2) with ESMTP id xB4IR4nI106520; Wed, 4 Dec 2019 12:27:05 -0600 Subject: Re: [PATCH v6 03/15] drm/bridge: tc358767: Simplify polling in tc_link_training() To: Andrey Smirnov , CC: Andrzej Hajda , Laurent Pinchart , Andrey Gusakov , Philipp Zabel , Cory Tusar , Chris Healy , Lucas Stach , , Jyri Sarha References: <20190619052716.16831-1-andrew.smirnov@gmail.com> <20190619052716.16831-4-andrew.smirnov@gmail.com> From: Tomi Valkeinen Message-ID: <0d84fa72-bc96-9b88-cd89-c04327109e0e@ti.com> Date: Wed, 4 Dec 2019 20:27:04 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.1 MIME-Version: 1.0 In-Reply-To: <20190619052716.16831-4-andrew.smirnov@gmail.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Andrey, On 19/06/2019 08:27, Andrey Smirnov wrote: > @@ -748,22 +748,19 @@ static int tc_set_video_mode(struct tc_data *tc, > > static int tc_wait_link_training(struct tc_data *tc) > { > - u32 timeout = 1000; > u32 value; > int ret; > > - do { > - udelay(1); > - tc_read(DP0_LTSTAT, &value); > - } while ((!(value & LT_LOOPDONE)) && (--timeout)); > - > - if (timeout == 0) { > + ret = tc_poll_timeout(tc, DP0_LTSTAT, LT_LOOPDONE, > + LT_LOOPDONE, 1, 1000); This seems to break DP at least with some monitors for me. I think it's just a timeout problem, as increasing the values helps. Using ktime, I can see that during link training, the first call takes ~2ms, the second ~7ms. I think this worked before, as udelay(1) takes much longer than 1 us. We have 1000us limit in a few other places too, which I don't see causing issues, but might need increasing too. Also, 1us sleep_us may be a bit too small to be sane. If the loops take milliseconds, probably 100us or even more would make sense. This didn't cause any issues with your display? Tomi -- Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki 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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 A439DC43603 for ; Wed, 4 Dec 2019 18:27:15 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 833F320661 for ; Wed, 4 Dec 2019 18:27:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 833F320661 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=ti.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D53396F4F0; Wed, 4 Dec 2019 18:27:14 +0000 (UTC) Received: from lelv0143.ext.ti.com (lelv0143.ext.ti.com [198.47.23.248]) by gabe.freedesktop.org (Postfix) with ESMTPS id BC3EC6F4F0 for ; Wed, 4 Dec 2019 18:27:13 +0000 (UTC) Received: from lelv0265.itg.ti.com ([10.180.67.224]) by lelv0143.ext.ti.com (8.15.2/8.15.2) with ESMTP id xB4IR9uL118997; Wed, 4 Dec 2019 12:27:09 -0600 Received: from DLEE109.ent.ti.com (dlee109.ent.ti.com [157.170.170.41]) by lelv0265.itg.ti.com (8.15.2/8.15.2) with ESMTPS id xB4IR9Tb051413 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 4 Dec 2019 12:27:09 -0600 Received: from DLEE115.ent.ti.com (157.170.170.26) by DLEE109.ent.ti.com (157.170.170.41) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1847.3; Wed, 4 Dec 2019 12:27:07 -0600 Received: from lelv0327.itg.ti.com (10.180.67.183) by DLEE115.ent.ti.com (157.170.170.26) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1847.3 via Frontend Transport; Wed, 4 Dec 2019 12:27:07 -0600 Received: from [192.168.2.6] (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0327.itg.ti.com (8.15.2/8.15.2) with ESMTP id xB4IR4nI106520; Wed, 4 Dec 2019 12:27:05 -0600 Subject: Re: [PATCH v6 03/15] drm/bridge: tc358767: Simplify polling in tc_link_training() To: Andrey Smirnov , References: <20190619052716.16831-1-andrew.smirnov@gmail.com> <20190619052716.16831-4-andrew.smirnov@gmail.com> From: Tomi Valkeinen Message-ID: <0d84fa72-bc96-9b88-cd89-c04327109e0e@ti.com> Date: Wed, 4 Dec 2019 20:27:04 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.1 MIME-Version: 1.0 In-Reply-To: <20190619052716.16831-4-andrew.smirnov@gmail.com> Content-Language: en-US X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 X-Mailman-Original-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1575484029; bh=Uet6ftlBWt6BLt4lGobOQD5+cFdGEWSfTiuKL7t91js=; h=Subject:To:CC:References:From:Date:In-Reply-To; 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