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 4E06E11187 for ; Mon, 8 Sep 2025 17:42:15 +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=1757353335; cv=none; b=XIViKF4qZBgtPANkB1dHtrLKSAKvDHkLdERKT2yP/dQO9aBamFfghoYzUVz0lJTgCHTAbdFI26w+JIRNJaGeak7uuUl9V9MnL0XZjn94pbDRDKbxUX4vxGr+boVWcTx6RkepT0lpD+hfeUUyMhep0s+hLpEBUiJYCN+XS58+HI0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757353335; c=relaxed/simple; bh=cmDjMsGmcydn3hGG0WomA86rZoUgbWUu3tCQXCV77o0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=EA9G2s0eIrqVkqzNH5VZxsPKcujPrBa6bkmbiWEtPUD+p8VPTjG4hkfrfHY9ES11CTy72Z6OCKv6rn2wAygn8cm2CYFgmPIgy12h6ENg+vT2ARfcRMVf8tck61uuZ6GvVLFuaGHbF/nA47a3V5oQVTH0GPtr52BygdmJ1KYHO7Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=lHX8aaZu; 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="lHX8aaZu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6D172C4CEF1; Mon, 8 Sep 2025 17:42:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1757353334; bh=cmDjMsGmcydn3hGG0WomA86rZoUgbWUu3tCQXCV77o0=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=lHX8aaZu8KMGoAhcyKGzh1xuunXh0RjO8ahdyLOGBZ4F64wDTFkyCl1xnhe+sNevD lIBOITPSiM35BL7mpi5f+Pz4WYKOGOhhP3srPPmsjftOWQBlt4BJElmoNaLisnNzmE 4G7DAN3LNEQ63vIh3y5s5NvZafMtnsxOgJS0/7VXozbjGTjElSRf3GmxvgJc6XkL0i MKLdjc+Z4cKXt3ekkh1Xfy9+hIU/+Ly3HuSY0rJku5IEiCqs5Z+KNi6Umlu7anqFJH jGV/kuhu3TjIL98JlKkbe5mg9Tb78k5Gf5v8mRIvJPSO/X7WqAgQQAs1tJ22Aj9X/i 2B6D+9MzdgK5g== Message-ID: Date: Tue, 9 Sep 2025 02:42:13 +0900 Precedence: bulk X-Mailing-List: linux-can@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH] can: dev: can_dev_dropped_skb: drop CAN FD skbs if FD is off To: Oliver Hartkopp , Marc Kleine-Budde Cc: linux-can@vger.kernel.org References: <20250907080504.598419-2-mailhol@kernel.org> <49e0970f-1a10-438f-b9ae-afcc75edaccd@hartkopp.net> <5edbe004-767f-4a41-9454-f4bbf8f5b590@kernel.org> <4e380c2b-f48d-4bd5-bc8d-3bfd85fc0d2f@hartkopp.net> <891c738e-f807-46a7-8e03-4223969c9002@kernel.org> <2f9fdf70-856c-4b4b-ac69-5e22f4d9e014@hartkopp.net> Content-Language: en-US From: Vincent Mailhol Autocrypt: addr=mailhol@kernel.org; keydata= xjMEZluomRYJKwYBBAHaRw8BAQdAf+/PnQvy9LCWNSJLbhc+AOUsR2cNVonvxhDk/KcW7FvN JFZpbmNlbnQgTWFpbGhvbCA8bWFpbGhvbEBrZXJuZWwub3JnPsKZBBMWCgBBFiEE7Y9wBXTm fyDldOjiq1/riG27mcIFAmdfB/kCGwMFCQp/CJcFCwkIBwICIgIGFQoJCAsCBBYCAwECHgcC F4AACgkQq1/riG27mcKBHgEAygbvORJOfMHGlq5lQhZkDnaUXbpZhxirxkAHwTypHr4A/joI 2wLjgTCm5I2Z3zB8hqJu+OeFPXZFWGTuk0e2wT4JzjgEZx4y8xIKKwYBBAGXVQEFAQEHQJrb YZzu0JG5w8gxE6EtQe6LmxKMqP6EyR33sA+BR9pLAwEIB8J+BBgWCgAmFiEE7Y9wBXTmfyDl dOjiq1/riG27mcIFAmceMvMCGwwFCQPCZwAACgkQq1/riG27mcJU7QEA+LmpFhfQ1aij/L8V zsZwr/S44HCzcz5+jkxnVVQ5LZ4BANOCpYEY+CYrld5XZvM8h2EntNnzxHHuhjfDOQ3MAkEK In-Reply-To: <2f9fdf70-856c-4b4b-ac69-5e22f4d9e014@hartkopp.net> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 09/09/2025 at 01:55, Oliver Hartkopp wrote: (...) > I think the best way is to properly split up the FD/XL capabilities for CAN XL > interfaces. Right now CAN FD is implicitly enabled on CAN XL interfaces when CAN > XL is enabled. > > I would tend to change the code in raw.c in a way that you have to switch on FD/ > XL explicitly. And then the problem would directly show up in write() and FD > frames would not be silently dropped in can_dev_dropped_skb(). If you can tweak raw.c to achieve this, it can be a better solution. I am just not sure how you are going to do that without breaking the UAPI. Looking forward for your patch! Yours sincerely, Vincent Mailhol