From patchwork Thu Jun 8 09:32:18 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arun R Murthy X-Patchwork-Id: 13271832 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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 7C34DC7EE29 for ; Thu, 8 Jun 2023 09:39:51 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E9F4910E40F; Thu, 8 Jun 2023 09:39:50 +0000 (UTC) Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by gabe.freedesktop.org (Postfix) with ESMTPS id DA95C10E40F for ; Thu, 8 Jun 2023 09:39:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1686217187; x=1717753187; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=2QrRl6vn6hRnBuWpvZTfYJfCAh8A/5NQ8H481g/KGeg=; b=CPuhtLqGjjwrgKBtfg0Gr5ybVtkOje+dYN7xDpZi6QyizU/RdrIYF+ti pI4k0qYba1a/VOa0MDzNixAt1D1QXUtLT3FPQFqmsQ6oVmITB9YYbcTxu +PTx7KaSC0Ir6Cgq3JBPAYH6XN+CFKxNWjCoRj4wkflFSqP7xWbmDewh6 ROo/sxJzAcf/E4lcdJ3IZqVEQMx2Rix6pYKVuBscZS3semEASYDH3VIfB kbGBhFcCl+/3avurk5hDLDc5a0ktoA7F7L2rTWcolOLNesjQMKGapT9vn KLIZPW6zkt0dcUPoPhZS3cHjm7vgY0dWRZvQPgB64YVFtpbheFGxA32B8 g==; X-IronPort-AV: E=McAfee;i="6600,9927,10734"; a="341918767" X-IronPort-AV: E=Sophos;i="6.00,226,1681196400"; d="scan'208";a="341918767" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Jun 2023 02:39:46 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10734"; a="854268560" X-IronPort-AV: E=Sophos;i="6.00,226,1681196400"; d="scan'208";a="854268560" Received: from srr4-3-linux-106-armuthy.iind.intel.com ([10.190.238.56]) by fmsmga001.fm.intel.com with ESMTP; 08 Jun 2023 02:39:45 -0700 From: Arun R Murthy To: intel-gfx@lists.freedesktop.org Date: Thu, 8 Jun 2023 15:02:18 +0530 Message-Id: <20230608093218.511280-1-arun.r.murthy@intel.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Subject: [Intel-gfx] [PATCHv2] drm/i915/display/dp: On AUX xfer timeout restart freshly X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" At the begining of the aux transfer a check for aux control busy bit is done. Then as per the spec on aux transfer timeout, need to retry freshly for 3 times with a delay which is taken care by the control register. On each of these 3 trials a check for busy has to be done so as to start freshly. v2: updated the commit message Signed-off-by: Arun R Murthy --- drivers/gpu/drm/i915/display/intel_dp_aux.c | 50 +++++++++------------ 1 file changed, 22 insertions(+), 28 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux.c b/drivers/gpu/drm/i915/display/intel_dp_aux.c index 197c6e81db14..25090542dd9f 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_aux.c +++ b/drivers/gpu/drm/i915/display/intel_dp_aux.c @@ -273,30 +273,6 @@ intel_dp_aux_xfer(struct intel_dp *intel_dp, * it using the same AUX CH simultaneously */ - /* Try to wait for any previous AUX channel activity */ - for (try = 0; try < 3; try++) { - status = intel_de_read_notrace(i915, ch_ctl); - if ((status & DP_AUX_CH_CTL_SEND_BUSY) == 0) - break; - msleep(1); - } - /* just trace the final value */ - trace_i915_reg_rw(false, ch_ctl, status, sizeof(status), true); - - if (try == 3) { - const u32 status = intel_de_read(i915, ch_ctl); - - if (status != intel_dp->aux_busy_last_status) { - drm_WARN(&i915->drm, 1, - "%s: not started (status 0x%08x)\n", - intel_dp->aux.name, status); - intel_dp->aux_busy_last_status = status; - } - - ret = -EBUSY; - goto out; - } - /* Only 5 data registers! */ if (drm_WARN_ON(&i915->drm, send_bytes > 20 || recv_size > 20)) { ret = -E2BIG; @@ -304,14 +280,31 @@ intel_dp_aux_xfer(struct intel_dp *intel_dp, } while ((aux_clock_divider = intel_dp->get_aux_clock_divider(intel_dp, clock++))) { - u32 send_ctl = intel_dp->get_aux_send_ctl(intel_dp, + /* Must try at least 3 times according to DP spec */ + for (try = 0; try < 5; try++) { + u32 send_ctl = intel_dp->get_aux_send_ctl(intel_dp, send_bytes, aux_clock_divider); - send_ctl |= aux_send_ctl_flags; + send_ctl |= aux_send_ctl_flags; + + /* Try to wait for any previous AUX channel activity */ + status = intel_dp_aux_wait_done(intel_dp); + /* just trace the final value */ + trace_i915_reg_rw(false, ch_ctl, status, sizeof(status), true); + + if (status & DP_AUX_CH_CTL_SEND_BUSY) { + drm_WARN(&i915->drm, 1, + "%s: not started, previous Tx still in process (status 0x%08x)\n", + intel_dp->aux.name, status); + intel_dp->aux_busy_last_status = status; + if (try > 3) { + ret = -EBUSY; + goto out; + } else + continue; + } - /* Must try at least 3 times according to DP spec */ - for (try = 0; try < 5; try++) { /* Load the send data into the aux channel data registers */ for (i = 0; i < send_bytes; i += 4) intel_de_write(i915, ch_data[i >> 2], @@ -321,6 +314,7 @@ intel_dp_aux_xfer(struct intel_dp *intel_dp, /* Send the command and wait for it to complete */ intel_de_write(i915, ch_ctl, send_ctl); + /* TODO: if typeC then 4.2ms else 800us. For DG2 add 1.5ms for both cases */ status = intel_dp_aux_wait_done(intel_dp); /* Clear done status and any errors */