From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B01F62F24 for ; Wed, 12 Apr 2023 08:51:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 38E9EC4339B; Wed, 12 Apr 2023 08:51:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1681289488; bh=/Q3UN315pK5M8c06heD37MxopiZUoKNSvu6wWmkTs/M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wIUMb9W8obKBTeLmWAkElMqJERnDj+mShCJvp1c/sbVp1bCZPOkjUvKMwXxLMrfE5 +FCpIZ/ZFRRsFHEgA5mPNvXXN9qg0vMmxYNXRbGrVsYcEeONcgbwOV97WeC2UWAfcW uLKTPM1dP3Cp9zk5seRous77sDN6qkp7nBMhs6ms= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Mario Limonciello , Hans de Goede , "Rafael J. Wysocki" Subject: [PATCH 6.2 117/173] ACPI: video: Make acpi_backlight=video work independent from GPU driver Date: Wed, 12 Apr 2023 10:34:03 +0200 Message-Id: <20230412082842.826157314@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230412082838.125271466@linuxfoundation.org> References: <20230412082838.125271466@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Hans de Goede commit e506731c8f35699d746c615164ed620cd53c00ca upstream. Commit 3dbc80a3e4c5 ("ACPI: video: Make backlight class device registration a separate step (v2)") combined with commit 5aa9d943e9b6 ("ACPI: video: Don't enable fallback path for creating ACPI backlight by default") Means that the video.ko code now fully depends on the GPU driver calling acpi_video_register_backlight() for the acpi_video# backlight class devices to get registered. This means that if the GPU driver does not do this, acpi_backlight=video on the cmdline, or DMI quirks for selecting acpi_video# will not work. This is a problem on for example Apple iMac14,1 all-in-ones where the monitor's LCD panel shows up as a regular DP connection instead of eDP so the GPU driver will not call acpi_video_register_backlight() [1]. Fix this by making video.ko directly register the acpi_video# devices when these have been explicitly requested either on the cmdline or through DMI quirks (rather then auto-detection being used). [1] GPU drivers only call acpi_video_register_backlight() when an internal panel is detected, to avoid non working acpi_video# devices getting registered on desktops which unfortunately is a real issue. Fixes: 5aa9d943e9b6 ("ACPI: video: Don't enable fallback path for creating ACPI backlight by default") Cc: All applicable Reviewed-by: Mario Limonciello Signed-off-by: Hans de Goede Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman --- drivers/acpi/acpi_video.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) --- a/drivers/acpi/acpi_video.c +++ b/drivers/acpi/acpi_video.c @@ -1984,6 +1984,7 @@ static int instance; static int acpi_video_bus_add(struct acpi_device *device) { struct acpi_video_bus *video; + bool auto_detect; int error; acpi_status status; @@ -2045,10 +2046,20 @@ static int acpi_video_bus_add(struct acp mutex_unlock(&video_list_lock); /* - * The userspace visible backlight_device gets registered separately - * from acpi_video_register_backlight(). + * If backlight-type auto-detection is used then a native backlight may + * show up later and this may change the result from video to native. + * Therefor normally the userspace visible /sys/class/backlight device + * gets registered separately by the GPU driver calling + * acpi_video_register_backlight() when an internal panel is detected. + * Register the backlight now when not using auto-detection, so that + * when the kernel cmdline or DMI-quirks are used the backlight will + * get registered even if acpi_video_register_backlight() is not called. */ acpi_video_run_bcl_for_osi(video); + if (__acpi_video_get_backlight_type(false, &auto_detect) == acpi_backlight_video && + !auto_detect) + acpi_video_bus_register_backlight(video); + acpi_video_bus_add_notify_handler(video); return 0;