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[23.128.96.18]) by mx.google.com with ESMTP id w21si4063231edd.421.2021.02.18.15.04.22; Thu, 18 Feb 2021 15:04:46 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@chromium.org header.s=google header.b=myyxUgL8; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=chromium.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229979AbhBRXDO (ORCPT + 99 others); Thu, 18 Feb 2021 18:03:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43396 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229577AbhBRXDN (ORCPT ); Thu, 18 Feb 2021 18:03:13 -0500 Received: from mail-pf1-x42b.google.com (mail-pf1-x42b.google.com [IPv6:2607:f8b0:4864:20::42b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 070E8C061756 for ; Thu, 18 Feb 2021 15:02:32 -0800 (PST) Received: by mail-pf1-x42b.google.com with SMTP id j12so2429538pfj.12 for ; Thu, 18 Feb 2021 15:02:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=mime-version:content-transfer-encoding:in-reply-to:references :subject:from:cc:to:date:message-id:user-agent; bh=vapw8v9gd6gzUZfgZWeHcnI7BY6UOi1UlhquxFwuYA8=; b=myyxUgL8UCCIqyF9TebzT62kDycJr1y+iVGqSe8euO0ZH6L0wL44ljB1lRBO2DwHFa pvcC4/CkIpCKc+n23ZHRreytCuqUSGCi268XsZZ6pRIUauZYc4IdG4pv6tWXXocLUIaW H918ZYZifVJj+zdvqTI+5BJzJUa91CWz8qH3s= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:content-transfer-encoding :in-reply-to:references:subject:from:cc:to:date:message-id :user-agent; bh=vapw8v9gd6gzUZfgZWeHcnI7BY6UOi1UlhquxFwuYA8=; b=AkjnIlDYXbma1ngKa301INGWtQsLVpuBg9dQtrygzrN0W9MtBoBT3Ug+xgGTzCif77 qzVCCCxx8gxoJ9QbkHeRGvIWKez4dLDlLdau4qGNHjXvTWrJE36hpR0ZX6WZvM76M5vy AJjMS+iXo++2wucvR+mqlGKepkcYxt8s0fbZzq/t+7B8JE79PVpTKMDAVBY0qdOe7lML dgNBFftEeBYb/ObTX6VQKHzCkPi42dDfDFHFzU5pt0BdO6mUr7uoc1HoPEohj7Sp1nXw r0DxmEWt+pO/KjXXeUSPfEKMaOqdHrK2A0wRYH18KXTmUmvLAOlhjhRtxSs1NQd0NVPX MEeA== X-Gm-Message-State: AOAM531uai68fTsdiq6qzlUHXNdtT6Tx1C2aSKOiPzhSx82gM/p9OPbi onqUTvR65x012+NCrHWPKWaW+w== X-Received: by 2002:a63:1409:: with SMTP id u9mr5796112pgl.312.1613689352388; Thu, 18 Feb 2021 15:02:32 -0800 (PST) Received: from chromium.org ([2620:15c:202:201:e561:d87c:c8df:56e2]) by smtp.gmail.com with ESMTPSA id c18sm6566737pgm.88.2021.02.18.15.02.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 18 Feb 2021 15:02:31 -0800 (PST) Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable In-Reply-To: <1613681704-12539-1-git-send-email-khsieh@codeaurora.org> References: <1613681704-12539-1-git-send-email-khsieh@codeaurora.org> Subject: Re: [PATCH v2 2/2] drm/msm/dp: add supported max link rate specified from dtsi From: Stephen Boyd Cc: tanmay@codeaurora.org, abhinavk@codeaurora.org, aravindh@codeaurora.org, khsieh@codeaurora.org, airlied@linux.ie, daniel@ffwll.ch, linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org, linux-kernel@vger.kernel.org To: Kuogee Hsieh , robdclark@gmail.com, sean@poorly.run Date: Thu, 18 Feb 2021 15:02:30 -0800 Message-ID: <161368935031.1254594.14384765673800900954@swboyd.mtv.corp.google.com> User-Agent: alot/0.9.1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Quoting Kuogee Hsieh (2021-02-18 12:55:04) > Allow supported link rate to be limited to the value specified at > dtsi. If it is not specified, then link rate is derived from dpcd > directly. Below are examples, > link-rate =3D <162000> for max link rate limited at 1.62G > link-rate =3D <270000> for max link rate limited at 2.7G > link-rate =3D <540000> for max link rate limited at 5.4G > link-rate =3D <810000> for max link rate limited at 8.1G >=20 > Changes in V2: > -- allow supported max link rate specified from dtsi Please don't roll this into the patch that removes the limit. The previous version of this patch was fine. The part that lowers the limit back down should be another patch. We rejected link-rate in DT before and we should reject it upstream again. As far as I can tell, the maximum link rate should be determined based on the panel or the type-c port on the board. The dp controller can always achieve HBR3, so limiting it at the dp controller is incorrect. The driver should query the endpoints to figure out if they want to limit the link rate. Is that done automatically sometimes by intercepting the DPCD?