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 X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 0D2A2C433DF for ; Tue, 16 Jun 2020 19:42:51 +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 D74A720810 for ; Tue, 16 Jun 2020 19:42:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D74A720810 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 7FF7F6E1BC; Tue, 16 Jun 2020 19:42:50 +0000 (UTC) Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by gabe.freedesktop.org (Postfix) with ESMTPS id 78C496E1BC for ; Tue, 16 Jun 2020 19:42:49 +0000 (UTC) IronPort-SDR: R2OslclG3hq2pTX2GbwZWE6Hbj5rgViDsWeFgZeTr2odUCJsArOi6szJEM9WeR4JG16YPUBa6K b6hLiIh19f0Q== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Jun 2020 12:42:47 -0700 IronPort-SDR: PvOodaQiwNNS4g7Ho4icx69413zpHnCbgSNP4RQYJCXh9jen7g1Ud4iagZlhz58BuqdtGCPBNH al6hSktuoUkQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,519,1583222400"; d="scan'208";a="317316284" Received: from stinkbox.fi.intel.com (HELO stinkbox) ([10.237.72.174]) by FMSMGA003.fm.intel.com with SMTP; 16 Jun 2020 12:42:45 -0700 Received: by stinkbox (sSMTP sendmail emulation); Tue, 16 Jun 2020 22:42:44 +0300 Date: Tue, 16 Jun 2020 22:42:44 +0300 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Manasi Navare Message-ID: <20200616194244.GJ6112@intel.com> References: <20200616193056.4817-1-manasi.d.navare@intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200616193056.4817-1-manasi.d.navare@intel.com> X-Patchwork-Hint: comment User-Agent: Mutt/1.10.1 (2018-07-13) Subject: Re: [Intel-gfx] [PATCH] drm/i915/dp: Poll for DDI Idle status to be 0 after enabling DDI Buf 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: , Cc: intel-gfx@lists.freedesktop.org Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Tue, Jun 16, 2020 at 12:30:56PM -0700, Manasi Navare wrote: > The Bspec sequence expects us to poll for DDI Idle status > to be 0 (not idle) with a timeout of 600usecs after enabling the > DDI BUF CTL. It only says that for newer platforms. We need to either keep the fixed delay before starting to poll, or someone needs confirm = how the idle bit really behaves on the older platforms. > But currently in the driver we just wait for 600usecs > without polling so add that. > = > Cc: Ville Syrj=E4l=E4 > Cc: Imre Deak > Signed-off-by: Manasi Navare > --- > drivers/gpu/drm/i915/display/intel_ddi.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > = > diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i= 915/display/intel_ddi.c > index ca7bb2294d2b..de7e15de0bc5 100644 > --- a/drivers/gpu/drm/i915/display/intel_ddi.c > +++ b/drivers/gpu/drm/i915/display/intel_ddi.c > @@ -4023,7 +4023,11 @@ static void intel_ddi_prepare_link_retrain(struct = intel_dp *intel_dp) > intel_de_write(dev_priv, DDI_BUF_CTL(port), intel_dp->DP); > intel_de_posting_read(dev_priv, DDI_BUF_CTL(port)); > = > - udelay(600); > + if (wait_for_us(!(intel_de_read(dev_priv, DDI_BUF_CTL(port)) & > + DDI_BUF_IS_IDLE), > + 600)) > + drm_err(&dev_priv->drm, "DDI port:%c buffer idle\n", > + port_name(port)); > } > = > static void intel_ddi_set_link_train(struct intel_dp *intel_dp, > -- = > 2.19.1 -- = Ville Syrj=E4l=E4 Intel _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx