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 DB76828C864 for ; Fri, 6 Mar 2026 12:43:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772800980; cv=none; b=R1KX51425F3maPXEubhECjYWzq18DBg60smVrnVN7vTfeZprKiOBD0vK9NRJOm9F5XdRJjxwgIKYcITDg+z1q4TtgPZSomJAGPXc/U1H8Y2/bQQaP8gDN8MPskQPNPj9cu0SK6fwbOpeDbNeU9JfRBUxMjBE5tZrSUEjw0chvE8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772800980; c=relaxed/simple; bh=gSmTssy6CNAAgTZVKgwAcfCJxvMXUcM2Ff7OKTcAWos=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=l363yODH8X8wtPVhb6b8fPD5a/ER+ElN3GuLT0zqdosGDQyGVPwrOXVZDWgZ1tbkAeuH5bY2v4+u0uEm3l14plqScCetPF2H8bjbf+JAhYnDJWOugW6YonTNKlWriF6bcLF1P45k/ArhJ9Uzqm3B/yBGqTsFywKgTzzD84ZOs5o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=l8tp9lUU; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="l8tp9lUU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E647DC4CEF7; Fri, 6 Mar 2026 12:42:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772800980; bh=gSmTssy6CNAAgTZVKgwAcfCJxvMXUcM2Ff7OKTcAWos=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=l8tp9lUU8gK29/LPrmM/X3xbs/Q/kG0p9AkRk6597v/jWPh9DFc6jtRJbN3RKvvXv qOFN4G+rOzpLisfr6HzzhwNIJL+dwKGf11RDCFLBKmDepUXRM8+1Pwrh7Ga1vamaoW gYaIrlz3XhxIdMSSGS+WSycxKTLiEdMJ16PgGFTI2yiPbIBJYAWJJNi9U0f7r4HQ5t 1OsZkjR7SzIOgqijY/2DLLnUq3QY5dBMFGaZWZnKdmDXdNTphpLDGHFL1tPlLABrRE eY+5zO5Jp1qgAYMf5rD3+/QEgQOzDCrJAHT2TABqvCeVwRHM5i7RukypKsZJv3LNUU pQ2IS1pbNs0Pg== Message-ID: <23a0f5f8-11a6-4f41-9e32-19cb08110bc6@kernel.org> Date: Fri, 6 Mar 2026 06:42:58 -0600 Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] ACPI: video: Don't allow MFD devices to probe To: "Rafael J. Wysocki" Cc: mario.limonciello@amd.com, W_Armin@gmx.de, Pratap Nirujogi , rafael.j.wysocki@intel.com, linux-acpi@vger.kernel.org References: <20260306025144.604062-1-superm1@kernel.org> Content-Language: en-US From: Mario Limonciello In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 3/6/26 6:17 AM, Rafael J. Wysocki wrote: > On Fri, Mar 6, 2026 at 11:50 AM Rafael J. Wysocki wrote: >> >> On Fri, Mar 6, 2026 at 3:51 AM Mario Limonciello (AMD) >> wrote: >>> >>> After ACPI video was converted into a platform device in >>> commit 02c057ddefef5 ("ACPI: video: Convert the driver to a platform one") >>> other devices that are MFD children of LNXVIDEO are being probed. >>> This isn't intended. >>> >>> During probe detect MFD cells and reject them. >>> >>> Fixes: 02c057ddefef5 ("ACPI: video: Convert the driver to a platform one") >>> Reported-by: Pratap Nirujogi >>> Closes: https://lore.kernel.org/regressions/007e3390-6b2b-457e-83c7-c794c5952018@amd.com/ >> >> The link is broken, so I can't see what is really happening, but my >> guess is that MFD devices are created under the video bus device and >> they get the same device ID (confusingly enough). Hmm, I just double checked the link and it worked for me. But you are on the To: list of that thread also. >> >>> Signed-off-by: Mario Limonciello (AMD) >>> --- >>> drivers/acpi/acpi_video.c | 4 ++++ >>> 1 file changed, 4 insertions(+) >>> >>> diff --git a/drivers/acpi/acpi_video.c b/drivers/acpi/acpi_video.c >>> index 3fa28f1abca38..2cb526775ac47 100644 >>> --- a/drivers/acpi/acpi_video.c >>> +++ b/drivers/acpi/acpi_video.c >>> @@ -14,6 +14,7 @@ >>> #include >>> #include >>> #include >>> +#include >>> #include >>> #include >>> #include >>> @@ -1988,6 +1989,9 @@ static int acpi_video_bus_probe(struct platform_device *pdev) >>> int error; >>> acpi_status status; >>> >>> + if (mfd_get_cell(pdev)) >>> + return -ENODEV; >> >> If the above is the case, I'd prefer this check >> >> if (!device->pnp.type.backlight) >> >> which should also work, but is more general. > > Well, this will not work if the ACPI companion is shared between > multiple devices. > > However, adding an MFD check here is a "works for me" change rather. > > I think what needs to be done is to extend the duplication check (see > my patch from yesterday at > https://lore.kernel.org/linux-acpi/5663583.Sb9uPGUboI@rafael.j.wysocki/) > to detect the cases when another platform device (not necessarily a > child of the same parent) sharing the same ACPI companion is probed. > Generally makes sense to me. But in this particular case it shouldn't be a FW_BUG. Do you want to roll this in your series? Or would you prefer one of us to send a follow up patch?