From patchwork Mon Nov 2 18:11:42 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stephen Boyd X-Patchwork-Id: 11876299 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=-12.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,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 4B8E7C388F2 for ; Tue, 3 Nov 2020 08:16:11 +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 E6335223BD for ; Tue, 3 Nov 2020 08:16:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="JBUs/ATc" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E6335223BD Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.org 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 0B4DE6EC3E; Tue, 3 Nov 2020 08:14:39 +0000 (UTC) Received: from mail-pl1-x641.google.com (mail-pl1-x641.google.com [IPv6:2607:f8b0:4864:20::641]) by gabe.freedesktop.org (Postfix) with ESMTPS id C9F186E117 for ; Mon, 2 Nov 2020 18:11:49 +0000 (UTC) Received: by mail-pl1-x641.google.com with SMTP id g11so713557pll.13 for ; Mon, 02 Nov 2020 10:11:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=Mucw0+S0CdtYt2MrRKtHgnlnbG3RdZ1CSuq3C9GPsWI=; b=JBUs/ATc6uaPEMghQ/X3xL58YiXfHxnNb2KJQlhhG6ZMIoCG6puCx17Mix5ZaIIktH O8MBOpsa+Hpbr+NJ90V/vYmzGqZcR3Q0grcapVGHvrG3pnQkz1VzWmLwRQbvoTUPMwS3 IKqh/NbK43OMImI8cujYwv8KvNtR3igfTvoLo= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=Mucw0+S0CdtYt2MrRKtHgnlnbG3RdZ1CSuq3C9GPsWI=; b=ZueliEkzO681W+XCgUdj67rM5xJhEJOwqTmSt+gILJmuPYCLYN/2IkJBaIyMFuW3En 7jDDZN09aHbkiIQ+s+nCbJF9qiQJZfzqIjL/c+1JDWSMnvsheKlYbcW8T34OJk4TgH7Z Ylo2wkC8kO3lZ2bRVRKDC8ViERrAD4O1fAukeQxUNdKPXGoMs5B8ookRkDnnQ7kYxily TN48OOUb3q+KZmOdxV/lqbdDEE1FkpB4PdFggbsiweeFjR5Jj/SOZRcSwYAmmFuzumcO okMbacWqZ4hXG9VKf03goRjflQB+5HHilESloz0G9HBalkxKk4K+A/VzFgb7N6Wm7LNF MkTA== X-Gm-Message-State: AOAM533dv2IeiZfw2a97xw6ljVbUpbrxsTBjLDmHnQAgx6IucRukqXX1 9zCSd+iAI7uyiAKnTXureaDvnQ== X-Google-Smtp-Source: ABdhPJyHYVx0D/MimpLNF9meNsmXNCFBi0+HKgmBxtQQHUNbkMk9oc+WHbulYskfoB1/sI0kTUilQg== X-Received: by 2002:a17:902:b689:b029:d5:e78f:65d1 with SMTP id c9-20020a170902b689b02900d5e78f65d1mr21923958pls.6.1604340709451; Mon, 02 Nov 2020 10:11:49 -0800 (PST) Received: from smtp.gmail.com ([2620:15c:202:201:3e52:82ff:fe6c:83ab]) by smtp.gmail.com with ESMTPSA id b17sm13175640pgb.94.2020.11.02.10.11.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 Nov 2020 10:11:48 -0800 (PST) From: Stephen Boyd To: Andrzej Hajda , Neil Armstrong , Sam Ravnborg Subject: [PATCH v3 2/4] drm/bridge: ti-sn65dsi86: Make polling a busy loop Date: Mon, 2 Nov 2020 10:11:42 -0800 Message-Id: <20201102181144.3469197-3-swboyd@chromium.org> X-Mailer: git-send-email 2.29.1.341.ge80a0c044ae-goog In-Reply-To: <20201102181144.3469197-1-swboyd@chromium.org> References: <20201102181144.3469197-1-swboyd@chromium.org> MIME-Version: 1.0 X-Mailman-Approved-At: Tue, 03 Nov 2020 08:14:25 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jernej Skrabec , Jonas Karlman , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Douglas Anderson , Sean Paul , Laurent Pinchart Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" There's no reason we need to wait here to poll a register over i2c. The i2c bus is inherently slow and delays are practically part of the protocol because we have to wait for the device to respond to any request for a register. Let's rely on the sleeping of the i2c controller instead of adding any sort of delay here in the bridge driver. Reviewed-by: Douglas Anderson Cc: Laurent Pinchart Cc: Jonas Karlman Cc: Jernej Skrabec Cc: Sean Paul Acked-by: Sam Ravnborg Signed-off-by: Stephen Boyd --- drivers/gpu/drm/bridge/ti-sn65dsi86.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index 87726b9e446f..8276fa50138f 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -881,9 +881,9 @@ static ssize_t ti_sn_aux_transfer(struct drm_dp_aux *aux, regmap_write(pdata->regmap, SN_AUX_CMD_REG, request_val | AUX_CMD_SEND); + /* Zero delay loop because i2c transactions are slow already */ ret = regmap_read_poll_timeout(pdata->regmap, SN_AUX_CMD_REG, val, - !(val & AUX_CMD_SEND), 200, - 50 * 1000); + !(val & AUX_CMD_SEND), 0, 50 * 1000); if (ret) return ret;