From patchwork Thu Mar 24 18:27:07 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: cpaul@redhat.com X-Patchwork-Id: 8663761 Return-Path: X-Original-To: patchwork-dri-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 0B787C0553 for ; Thu, 24 Mar 2016 18:27:55 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 1F5FB2038E for ; Thu, 24 Mar 2016 18:27:54 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 3BAAC202AE for ; Thu, 24 Mar 2016 18:27:53 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 7BDDC6E109; Thu, 24 Mar 2016 18:27:26 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by gabe.freedesktop.org (Postfix) with ESMTPS id 3A0A889872; Thu, 24 Mar 2016 18:27:24 +0000 (UTC) Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (Postfix) with ESMTPS id DB4A17AEB1; Thu, 24 Mar 2016 18:27:23 +0000 (UTC) Received: from ecstaticemu.bos.redhat.com (dhcp-25-74.bos.redhat.com [10.18.25.74]) by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u2OIRKdB019205; Thu, 24 Mar 2016 14:27:23 -0400 From: Lyude To: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Subject: [PATCH v4 2/5] drm/dp_helper: Always wait before retrying native aux transactions Date: Thu, 24 Mar 2016 14:27:07 -0400 Message-Id: <1458844031-2032-3-git-send-email-cpaul@redhat.com> In-Reply-To: <1458844031-2032-1-git-send-email-cpaul@redhat.com> References: <1458761417-12165-1-git-send-email-cpaul@redhat.com> <1458844031-2032-1-git-send-email-cpaul@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.26 Cc: arthur.j.runyan@intel.com, open list , Lyude X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This is part of a patch series to migrate all of the workarounds for commonly seen behavior from bad sinks in intel_dp_dpcd_read_wake() to drm's DP helper. Some sinks need some time during the process of resuming the system from sleep before they're ready to handle transactions. While it would be nice if they responded with NACKs in these scenarios, this isn't always the case as a few sinks will just timeout on all of the transactions they receive until they're ready. Signed-off-by: Lyude --- drivers/gpu/drm/drm_dp_helper.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index d1128fb..3b915e2 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -179,7 +179,7 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, { struct drm_dp_aux_msg msg; unsigned int retry; - int err; + int err = 0; memset(&msg, 0, sizeof(msg)); msg.address = offset; @@ -194,6 +194,10 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, * sufficient, bump to 32 which makes Dell 4k monitors happier. */ for (retry = 0; retry < 32; retry++) { + if (err != 0 && err != -ETIMEDOUT) { + usleep_range(AUX_RETRY_INTERVAL, + AUX_RETRY_INTERVAL + 100); + } mutex_lock(&aux->hw_mutex); err = aux->transfer(aux, &msg); @@ -205,7 +209,6 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, return err; } - switch (msg.reply & DP_AUX_NATIVE_REPLY_MASK) { case DP_AUX_NATIVE_REPLY_ACK: if (err < size) @@ -214,10 +217,6 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, case DP_AUX_NATIVE_REPLY_NACK: return -EIO; - - case DP_AUX_NATIVE_REPLY_DEFER: - usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100); - break; } }