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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id ADE7DC54E58 for ; Mon, 18 Mar 2024 17:06:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=R/9G/otGNsycaRMspviLgM5YZDWssU43q7EHAXnKiQ0=; b=t15cI3HaSnOsj9 FahW6OKoqzeOtyt5NyJ8RBH2h1O1gZ6nbW4plN5Hk/qZlvzKCslxgZ2rZSVnOqj8rweDmTFpSjghF 3L9s9+WWIu0foL/XNkU71MkIqHBey5XlAik9pmeXsPhspvAp8ZjBEf+IbR5HIu0n3OqoNIjIbKLvL QZ1BEjVgCTWx4RDT+AA5t8bbCALqdkYYACqnkUzuzV4gzmoMYPRLHeef8gyrx6Yq9iP9fX/8qL2J4 O3zUk7fUiOldWxOHXZQzZHHQksoewVq60+IsSbFO+QX2VmzUhDy3xt02D8bADE8kiTD4Cp2jxDNaz d1Nu0w+k7df0lzc+BtKg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rmGRM-00000009N4w-429V; Mon, 18 Mar 2024 17:06:25 +0000 Received: from perceval.ideasonboard.com ([213.167.242.64]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rmGRF-00000009N29-1q2L for linux-arm-kernel@lists.infradead.org; Mon, 18 Mar 2024 17:06:18 +0000 Received: from pendragon.ideasonboard.com (81-175-209-231.bb.dnainternet.fi [81.175.209.231]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 559FC7E9; Mon, 18 Mar 2024 18:05:46 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1710781546; bh=eKN5dVb6S67RCse9OvAtbGcBmvx7pJXmDkiVK8Z0e+c=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=i3kvDuWkLq/GiBhR3QIPVDrAbeGf2rohEQFoFP1kp3E1QlJMGQVq8dCZ/1/LqZaTq s7O6fu5qm2u4JCv8LYulyvpFUdqx/eBygmA+76O2MKUFbGbdcJPhFJ0gtvb3r4PqIG y5gEEKwAIOGStoEixXkaiqURFWsFiXWwoXy1dG4E= Date: Mon, 18 Mar 2024 19:06:09 +0200 From: Laurent Pinchart To: Sean Anderson Cc: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , dri-devel@lists.freedesktop.org, David Airlie , linux-kernel@vger.kernel.org, Michal Simek , linux-arm-kernel@lists.infradead.org, Daniel Vetter Subject: Re: [PATCH 2/6] drm: zynqmp_dp: Adjust training values per-lane Message-ID: <20240318170609.GI13682@pendragon.ideasonboard.com> References: <20240315230916.1759060-1-sean.anderson@linux.dev> <20240315230916.1759060-3-sean.anderson@linux.dev> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20240315230916.1759060-3-sean.anderson@linux.dev> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240318_100617_631856_FFE08183 X-CRM114-Status: GOOD ( 18.78 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Sean, Thank you for the patch. On Fri, Mar 15, 2024 at 07:09:12PM -0400, Sean Anderson wrote: > The feedback we get from the DPRX is per-lane. Make changes using this > information, instead of picking the maximum values from all lanes. This > results in more-consistent training on marginal links. > > Signed-off-by: Sean Anderson > --- > > drivers/gpu/drm/xlnx/zynqmp_dp.c | 23 ++++++++--------------- > 1 file changed, 8 insertions(+), 15 deletions(-) > > diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c > index 98a32e6a0459..8635b5673386 100644 > --- a/drivers/gpu/drm/xlnx/zynqmp_dp.c > +++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c > @@ -605,28 +605,21 @@ static void zynqmp_dp_adjust_train(struct zynqmp_dp *dp, > u8 link_status[DP_LINK_STATUS_SIZE]) > { > u8 *train_set = dp->train_set; > - u8 voltage = 0, preemphasis = 0; > u8 i; > > for (i = 0; i < dp->mode.lane_cnt; i++) { > - u8 v = drm_dp_get_adjust_request_voltage(link_status, i); > - u8 p = drm_dp_get_adjust_request_pre_emphasis(link_status, i); > + u8 voltage = drm_dp_get_adjust_request_voltage(link_status, i); > + u8 preemphasis = > + drm_dp_get_adjust_request_pre_emphasis(link_status, i); > > - if (v > voltage) > - voltage = v; > + if (voltage >= DP_TRAIN_VOLTAGE_SWING_LEVEL_3) > + voltage |= DP_TRAIN_MAX_SWING_REACHED; > > - if (p > preemphasis) > - preemphasis = p; > - } > + if (preemphasis >= DP_TRAIN_PRE_EMPH_LEVEL_2) > + preemphasis |= DP_TRAIN_MAX_PRE_EMPHASIS_REACHED; > > - if (voltage >= DP_TRAIN_VOLTAGE_SWING_LEVEL_3) > - voltage |= DP_TRAIN_MAX_SWING_REACHED; > - > - if (preemphasis >= DP_TRAIN_PRE_EMPH_LEVEL_2) > - preemphasis |= DP_TRAIN_MAX_PRE_EMPHASIS_REACHED; > - > - for (i = 0; i < dp->mode.lane_cnt; i++) > train_set[i] = voltage | preemphasis; > + } I don't have enough DP knowledge to review this :-( > } > > /** -- Regards, Laurent Pinchart _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel