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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 8F4A0C4360C for ; Thu, 10 Oct 2019 08:46:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5AA9F2190F for ; Thu, 10 Oct 2019 08:46:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570697176; bh=ULwYx4Q1NCG16srlI3fJS7zmEXdK3GkZILdEY+2LNlY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=FcyeO+Cl6Jsfe8LW7UUB+AHvaD4bfJL7a8KWdEDGggYkurUSJMUzHGDEboWnjXMk2 jDAVvnzeczHC9G0dMu84PAyrCYCOKnlmWBfEJmdDpFQ4KroDVKOVonSKqOKit5grDa Sax2uMZSnvZyzXJk+7eP2WUoqtmduYl9LjPGa//I= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389293AbfJJIqO (ORCPT ); Thu, 10 Oct 2019 04:46:14 -0400 Received: from mail.kernel.org ([198.145.29.99]:51980 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389269AbfJJIqM (ORCPT ); Thu, 10 Oct 2019 04:46:12 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C0384208C3; Thu, 10 Oct 2019 08:46:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570697171; bh=ULwYx4Q1NCG16srlI3fJS7zmEXdK3GkZILdEY+2LNlY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=B+72YhTuXkOp0DgnemKSAuUU3HRntgcmL0y9by+U3Nd5505MZXOXsiWrBzbOV4VV8 Ayr/K2JZTqb9I5U0sv5xmoCUgRb4+6BPkK5DaqUgcG7VJ9eF3q9br6eFJjLnyoT88S kxWOey4vGY8x61OV1gM+dmBR/pa8ctuKDHduOwgs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tomi Valkeinen , Adam Ford , Jyri Sarha Subject: [PATCH 4.19 037/114] drm/omap: fix max fclk divider for omap36xx Date: Thu, 10 Oct 2019 10:35:44 +0200 Message-Id: <20191010083603.611123885@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191010083544.711104709@linuxfoundation.org> References: <20191010083544.711104709@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Tomi Valkeinen commit e2c4ed148cf3ec8669a1d90dc66966028e5fad70 upstream. 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 Link: https://patchwork.freedesktop.org/patch/msgid/20191002122542.8449-1-tomi.valkeinen@ti.com Tested-by: Adam Ford Reviewed-by: Jyri Sarha Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/omapdrm/dss/dss.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/gpu/drm/omapdrm/dss/dss.c +++ b/drivers/gpu/drm/omapdrm/dss/dss.c @@ -1110,7 +1110,7 @@ static const struct dss_features omap34x 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",