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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 25212C432BE for ; Wed, 1 Sep 2021 15:32:26 +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 D576561057 for ; Wed, 1 Sep 2021 15:32:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org D576561057 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=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 5A4016E1FB; Wed, 1 Sep 2021 15:32:25 +0000 (UTC) Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by gabe.freedesktop.org (Postfix) with ESMTPS id 351D16E1FB for ; Wed, 1 Sep 2021 15:32:23 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10094"; a="198341697" X-IronPort-AV: E=Sophos;i="5.84,369,1620716400"; d="scan'208";a="198341697" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Sep 2021 08:32:22 -0700 X-IronPort-AV: E=Sophos;i="5.84,369,1620716400"; d="scan'208";a="532238688" Received: from josearun-mobl1.gar.corp.intel.com (HELO localhost) ([10.251.212.211]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Sep 2021 08:32:19 -0700 From: Jani Nikula To: Lee Shawn C , intel-gfx@lists.freedesktop.org Cc: Lee Shawn C , Ville Syrjala , Vandita Kulkarni , Cooper Chiou , William Tseng In-Reply-To: <20210901085445.427-6-shawn.c.lee@intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20210901085445.427-1-shawn.c.lee@intel.com> <20210901085445.427-6-shawn.c.lee@intel.com> Date: Wed, 01 Sep 2021 18:32:15 +0300 Message-ID: <871r68b9c0.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Intel-gfx] [PATCH 5/5] drm/i915/dsi: Read/write proper brightness value via MIPI DCS command 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" On Wed, 01 Sep 2021, Lee Shawn C wrote: > Driver has to swap the endian before send brightness level value > to tcon. > > v2: Use __be16 instead of u16 to fix sparse warning. > v3: Send one or two bytes brightness value depend on the precision. > > Reported-by: kernel test robot > Cc: Ville Syrjala > Cc: Jani Nikula > Cc: Vandita Kulkarni > Cc: Cooper Chiou > Cc: William Tseng > Signed-off-by: Lee Shawn C > --- > .../drm/i915/display/intel_dsi_dcs_backlight.c | 15 +++++++++------ > 1 file changed, 9 insertions(+), 6 deletions(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c b/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c > index 21ab9e1acb57..722411b5cb21 100644 > --- a/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c > +++ b/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c > @@ -47,33 +47,36 @@ static u32 dcs_get_backlight(struct intel_connector *connector, enum pipe unused > { > struct intel_encoder *encoder = intel_attached_encoder(connector); > struct intel_dsi *intel_dsi = enc_to_intel_dsi(encoder); > + struct intel_panel *panel = &connector->panel; > struct mipi_dsi_device *dsi_device; > - u8 data = 0; > + u8 data[2] = {0, 0}; u8 data[2] = {}; > enum port port; size_t len = panel->backlight.max > U8_MAX ? 2 : 1; > > /* FIXME: Need to take care of 16 bit brightness level */ > for_each_dsi_port(port, intel_dsi->dcs_backlight_ports) { > dsi_device = intel_dsi->dsi_hosts[port]->device; > mipi_dsi_dcs_read(dsi_device, MIPI_DCS_GET_DISPLAY_BRIGHTNESS, > - &data, sizeof(data)); > + &data, > + (panel->backlight.max >> 8) ? sizeof(data) : 1); > break; > } > > - return data; > + return ((data[1] << 8) | data[0]); Unnecessary braces around the whole thing. > } > > static void dcs_set_backlight(const struct drm_connector_state *conn_state, u32 level) > { > struct intel_dsi *intel_dsi = enc_to_intel_dsi(to_intel_encoder(conn_state->best_encoder)); > + struct intel_panel *panel = &to_intel_connector(conn_state->connector)->panel; > struct mipi_dsi_device *dsi_device; > - u8 data = level; > + __be16 data = cpu_to_be16(level); I think it's confusing to use __be16 in set and u8 data[2] in get. Let's just use u8 data[2] in both. Especially because this one will always write 0 for len == 1 as it's big-endian data! You may have to do something like to keep it clear: size_t len = panel->backlight.max > U8_MAX ? 2 : 1; if (len == 1) { data[0] = level; } else { data[0] = level >> 8; data[1] = level; } > enum port port; > > - /* FIXME: Need to take care of 16 bit brightness level */ > for_each_dsi_port(port, intel_dsi->dcs_backlight_ports) { > dsi_device = intel_dsi->dsi_hosts[port]->device; > mipi_dsi_dcs_write(dsi_device, MIPI_DCS_SET_DISPLAY_BRIGHTNESS, > - &data, sizeof(data)); > + &data, > + (panel->backlight.max >> 8) ? sizeof(data) : 1); > } > } -- Jani Nikula, Intel Open Source Graphics Center