From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from ms.lwn.net (ms.lwn.net [45.79.88.28]) (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 B862E1EEA20; Mon, 17 Mar 2025 22:53:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.79.88.28 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742252032; cv=none; b=Iqk576PUkrPc1zkt5QHEHOZn3IdZW4slAU2oJn4j8z3AW/tyvkL/X2+wBsGd0joptUM8ZmH8f+DgU3DTeQXmZ1yCc0jAAYuJfSznFNCs2hsGzBr8lNTi3mdo80L/XcNvURA1EROPJCV70OrIhqOr0YPFbtJqRtYnTxY9XNH/txk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742252032; c=relaxed/simple; bh=1S1wcpOAxOJ4DHTjH1VO4jxPlklt6ZOU7On+F2Rgyjk=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=RXxRN/iZ5C5vFHbx8N6FzTILG/bESEVJvQrYNdWsGjV08iWedGoAeKGv2MaiXh9xxD1kb3Zw+ty8DIsddS8eIG+QBug19M+Wo4iVKuGc2SdDG6Vs5I4B7GdA+xM3qHSOHqYEltt59CjyhMyqw26M+0ZHNb9l+ZdELN2bdsAh0jw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lwn.net; spf=pass smtp.mailfrom=lwn.net; dkim=pass (2048-bit key) header.d=lwn.net header.i=@lwn.net header.b=sjGTpFcW; arc=none smtp.client-ip=45.79.88.28 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lwn.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lwn.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=lwn.net header.i=@lwn.net header.b="sjGTpFcW" DKIM-Filter: OpenDKIM Filter v2.11.0 ms.lwn.net CA02E41081 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=lwn.net; s=20201203; t=1742252030; bh=m1ArYPexXQLLtsttigae2e4aJ3hQRaLakaXfUFdgBoY=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=sjGTpFcWrFNyxcrEhg5znWVSCMX/Jxov0q9Ugh8gtnqqZboBDzXiAlylqrhRY2zi1 cyIGLnkpswu+aJtUY2TZFzVxJp5OtmTs2P6lw6wCWVbxIjHv9FM/b8k656bRWLHLaV IuhbgxUjA3neuEQ3ZllosRbua/ZfRVTLxtuJzGbPskBFHH+A8gwLanTpL4YSk5Rnhk xKToCE+f5fDf2QwgTp9qiWfUyAm1N7yKJA7tJq1AlBPoNPjGlJG83tN41wUr7ewT3Z P1JXzlHeb8updjN+8+EUEZwreC8NacJv2vgz5hPP5DZ+bfIcUze43tjUudxE7PLO28 j0KiF4vKWTBRw== Received: from localhost (unknown [IPv6:2601:280:4600:2da9::1fe]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by ms.lwn.net (Postfix) with ESMTPSA id CA02E41081; Mon, 17 Mar 2025 22:53:49 +0000 (UTC) From: Jonathan Corbet To: Jacek Lawrynowicz Cc: linux-doc@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, simona.vetter@ffwll.ch, airlied@gmail.com, Jacek Lawrynowicz Subject: Re: [PATCH] docs: driver-api: firmware: clarify userspace requirements In-Reply-To: <20250314100137.2972355-1-jacek.lawrynowicz@linux.intel.com> References: <20250314100137.2972355-1-jacek.lawrynowicz@linux.intel.com> Date: Mon, 17 Mar 2025 16:53:49 -0600 Message-ID: <874izre0aq.fsf@trenco.lwn.net> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Jacek Lawrynowicz writes: > The guidelines mention that firmware updates can't break the kernel, > but it doesn't state directly that they can't break userspace programs. > Make it explicit that firmware updates cannot break UAPI. > > Signed-off-by: Jacek Lawrynowicz > --- > .../driver-api/firmware/firmware-usage-guidelines.rst | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/Documentation/driver-api/firmware/firmware-usage-guidelines.rst b/Documentation/driver-api/firmware/firmware-usage-guidelines.rst > index fdcfce42c6d28..5f8f13e2ee510 100644 > --- a/Documentation/driver-api/firmware/firmware-usage-guidelines.rst > +++ b/Documentation/driver-api/firmware/firmware-usage-guidelines.rst > @@ -42,3 +42,8 @@ then of course these rules will not apply strictly.) > deprecating old major versions, then this should only be done as a > last option, and be stated clearly in all communications. > > +* Firmware files that affect the User API (UAPI) shall not introduce > + changes that break existing userspace programs. Updates to such firmware > + must ensure backward compatibility with existing userspace applications. > + This includes maintaining consistent interfaces and behaviors that > + userspace programs rely on. > \ No newline at end of file This ^^^^^^^^^^^^^^^^^^^^^^^^ is a good thing to avoid. That can be fixed up at apply time. Dave, you're the only one with fingerprints on this document; is the change OK with you? Thanks, jon