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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8C308E7D0A0 for ; Thu, 21 Sep 2023 17:12:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230254AbjIURMM (ORCPT ); Thu, 21 Sep 2023 13:12:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59634 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231612AbjIURKj (ORCPT ); Thu, 21 Sep 2023 13:10:39 -0400 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3FDDCAD1F for ; Thu, 21 Sep 2023 10:06:02 -0700 (PDT) Received: from pendragon.ideasonboard.com (213-243-189-158.bb.dnainternet.fi [213.243.189.158]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id F2F7D10FE; Thu, 21 Sep 2023 14:11:15 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1695298276; bh=iO0UHzPBM95Q2gC6Mfq+/hI5nIK6J68Fe0rzREmv7NM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=tmdFjAhuh7h5Bc4T4ykOgiI5rN/HF3hDjOgZBMb3SvMmlHDpiNUNtzd1ETXeasVyE uGPn/i3q44xCOIfwXRVpl0RdQZnxsR0dBQ0qadut6wzJ+VC2yuOm/TOIiPvDedA0La 6OVXn2zaAPqz2u24lt/qZ4NgAw9hzyng/C1N6vJA= Date: Thu, 21 Sep 2023 15:13:05 +0300 From: Laurent Pinchart To: Jani Nikula Cc: Xin Ji , Andrzej Hajda , Neil Armstrong , Robert Foss , Jonas Karlman , Jernej Skrabec , David Airlie , Daniel Vetter , qwen@analogixsemi.com, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, hsinyi@chromium.org, bliang@analogixsemi.com Subject: Re: [PATCH] drm/bridge: Add 200ms delay to wait FW HPD status stable Message-ID: <20230921121305.GA19112@pendragon.ideasonboard.com> References: <20230921091435.3524869-1-xji@analogixsemi.com> <87leczpw2h.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <87leczpw2h.fsf@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The subject line is missing the driver name. On Thu, Sep 21, 2023 at 03:09:10PM +0300, Jani Nikula wrote: > On Thu, 21 Sep 2023, Xin Ji wrote: > > For the none-interrupt design(sink device is panel, polling HPD s/none-interrupt/no-interrupt/ ? s/design/design / > > status when chip power on), anx7625 FW has more than 200ms HPD > > de-bounce time in FW, for the safety to get HPD status, driver > > better to wait 200ms before HPD detection after OS resume back. > > > > Signed-off-by: Xin Ji > > --- > > drivers/gpu/drm/bridge/analogix/anx7625.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c > > index 51abe42c639e..833d6d50a03d 100644 > > --- a/drivers/gpu/drm/bridge/analogix/anx7625.c > > +++ b/drivers/gpu/drm/bridge/analogix/anx7625.c > > @@ -1464,6 +1464,9 @@ static int _anx7625_hpd_polling(struct anx7625_data *ctx, > > if (ctx->pdata.intp_irq) > > return 0; > > > > + /* Delay 200ms for FW HPD de-bounce */ > > + usleep_range(200000, 201000); > > If you need to sleep for 200 ms, maybe use msleep instead? fsleep() could be a nice replacement. > > + > > ret = readx_poll_timeout(anx7625_read_hpd_status_p0, > > ctx, val, > > ((val & HPD_STATUS) || (val < 0)), -- Regards, Laurent Pinchart