From patchwork Wed Oct 2 12:25:42 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tomi Valkeinen X-Patchwork-Id: 11171001 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E32E91599 for ; Wed, 2 Oct 2019 12:26:13 +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 CB24421D82 for ; Wed, 2 Oct 2019 12:26:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CB24421D82 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 25ED26E966; Wed, 2 Oct 2019 12:26:13 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from fllv0016.ext.ti.com (fllv0016.ext.ti.com [198.47.19.142]) by gabe.freedesktop.org (Postfix) with ESMTPS id DD6EA6E966 for ; Wed, 2 Oct 2019 12:26:11 +0000 (UTC) Received: from lelv0265.itg.ti.com ([10.180.67.224]) by fllv0016.ext.ti.com (8.15.2/8.15.2) with ESMTP id x92CPxJx073005; Wed, 2 Oct 2019 07:25:59 -0500 Received: from DLEE102.ent.ti.com (dlee102.ent.ti.com [157.170.170.32]) by lelv0265.itg.ti.com (8.15.2/8.15.2) with ESMTPS id x92CPxgN120509 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 2 Oct 2019 07:25:59 -0500 Received: from DLEE109.ent.ti.com (157.170.170.41) by DLEE102.ent.ti.com (157.170.170.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5; Wed, 2 Oct 2019 07:25:47 -0500 Received: from lelv0327.itg.ti.com (10.180.67.183) 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 15.1.1713.5 via Frontend Transport; Wed, 2 Oct 2019 07:25:47 -0500 Received: from deskari.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0327.itg.ti.com (8.15.2/8.15.2) with ESMTP id x92CPu7F109850; Wed, 2 Oct 2019 07:25:56 -0500 From: Tomi Valkeinen To: Subject: [PATCH] drm/omap: fix max fclk divider for omap36xx Date: Wed, 2 Oct 2019 15:25:42 +0300 Message-ID: <20191002122542.8449-1-tomi.valkeinen@ti.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 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=1570019159; bh=EDYFrWfYHk5McenIprwnW2MZAkgJrfgPI50SZBwt2Ak=; h=From:To:CC:Subject:Date; b=B0sleF8CLZS8WkFm0/QCECxFDGUTuy+0CYJ6QkvIiCQI+y/WMvo/RQLKn6JSGc2Bu W2KhAmDmai4/1lbVQkO38S3Ige5V4doXMW1HzyUZTUmSN7hbgArWkOSMij49khBchf OvAzJeBOV4fLagmSw+dzlnGnvLxERnX5XeGg4B+w= X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "H . Nikolaus Schaller" , Tomi Valkeinen , linux-omap@vger.kernel.org, Adam Ford , stable@vger.kernel.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" The OMAP36xx and AM/DM37x TRMs say that the maximum divider for DSS fclk (in CM_CLKSEL_DSS) is 32. Experimentation shows that this is not correct, and using divider of 32 breaks DSS with a flood or underflows and sync losts. Dividers up to 31 seem to work fine. There is another patch to the DT files to limit the divider correctly, but as the DSS driver also needs to know the maximum divider to be able to iteratively find good rates, we also need to do the fix in the DSS driver. Signed-off-by: Tomi Valkeinen Cc: Adam Ford Cc: stable@vger.kernel.org Tested-by: Adam Ford Reviewed-by: Jyri Sarha --- drivers/gpu/drm/omapdrm/dss/dss.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/omapdrm/dss/dss.c b/drivers/gpu/drm/omapdrm/dss/dss.c index e226324adb69..4bdd63b57100 100644 --- a/drivers/gpu/drm/omapdrm/dss/dss.c +++ b/drivers/gpu/drm/omapdrm/dss/dss.c @@ -1083,7 +1083,7 @@ static const struct dss_features omap34xx_dss_feats = { static const struct dss_features omap3630_dss_feats = { .model = DSS_MODEL_OMAP3, - .fck_div_max = 32, + .fck_div_max = 31, .fck_freq_max = 173000000, .dss_fck_multiplier = 1, .parent_clk_name = "dpll4_ck",