From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 D39C1F9E8 for ; Mon, 26 May 2025 13:12:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748265167; cv=none; b=PpMC9kZN1DpVGvvpktbny+IUjj273wdTKjZI+0dnp2OuTJ2peCgQ43lbChGF7Xm+wIXH4fbEfo0dXK7XlKZ4A/srQ3g6727lFntKhNBtmBWApW4YxfDMFfbILpv8vUbm5Cc0EdUBEa68odcDJR0kJ2/BfczpAbPSMcbEJ6n4lJ4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748265167; c=relaxed/simple; bh=vZhyA16i4QBSEsNG/mrzQfpgHB+jBlz4tGq06KsD/94=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=j0NAcH+t4UlQGrobsQN+IynKeuyLqf+wPK+OiIRplKWVSxAHQFaGfo3I3KlVrOKVqlNXcq+9dcjQ8MpiC+eOmRpkJfCgudSzylUOZavpcMvh4qScYW1EduUdPCX9ixa15I/h5pobbG2qYb1EVYtyJmEmdmBFDlYK17IKVkHdghM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=KSrKYNp7; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="KSrKYNp7" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1748265163; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=LGsF0H7qCgK7/aWOj+Nk3etjewi4LnEg9nKOYPaMqno=; b=KSrKYNp7EilJdui/sGMacITXZj52v1J/evVB9CvHCqi8itrWugMjv3pPTU8O/qYfvKP4e1 ppmzmatN6FOgUMkX3REHCUMgFHxocbCdPM/hUtZ6+Mci9mC6a5pjX2dkws59KqabL72ZQE bpKtQuPCwuIsgXCYyfZJe5n5OP4Gm3U= Received: from mail-ej1-f71.google.com (mail-ej1-f71.google.com [209.85.218.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-382-tgGLENOpPUSr5xjm3p2H_g-1; Mon, 26 May 2025 09:12:41 -0400 X-MC-Unique: tgGLENOpPUSr5xjm3p2H_g-1 X-Mimecast-MFC-AGG-ID: tgGLENOpPUSr5xjm3p2H_g_1748265161 Received: by mail-ej1-f71.google.com with SMTP id a640c23a62f3a-ad53aaae592so224306866b.0 for ; Mon, 26 May 2025 06:12:41 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1748265161; x=1748869961; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=LGsF0H7qCgK7/aWOj+Nk3etjewi4LnEg9nKOYPaMqno=; b=r/WvHruusL86PlDsECUJDyY9Ds7jxbdp7jEegQXSxW6zJ/GP0j0DHQecNpFl0G2pob Q08xgn5yjDnaJ6jBgUUSA4XYttMmGA2SxkXXyKdMAXD1VFwrUNlvdG2/a3G5A8SEZxyO +FXgeCDMQ/Td56jxks98giIh/HpSlmiRdUMf/j6gC1sH5N3oyzT+B+zMNaGGj8B9vyYh ADJjeMLVO9LpPYYJQpDJQqzfzIsicMa3+CJxW+SBMLau2NyAqOdb8Xr0x9fFiKIgq6ho t6y4rhq7+f5rMn2GQLSZ4Zf1YnWswakKCV+KeGz28QDyp7dfk9NSZkPN8Ul3OlDNNG9a RyDg== X-Gm-Message-State: AOJu0YyD0TJgIWvXNC5FvA7NeMTF4fgdeQBPO89ckVmSWRYRAgV5soQv ep9NLx7IMzxp99Dr4mtPaWDPbxPoVRZY52sfJn24KNJnHJOW59z7QN3HI3TqpJsd+BDSQ8nr3y2 ds2alsSnkNUDA8fXIC9VRNvG5DQ7dZLDg0yNxNZDCiRujS7xmCX7zZgppK2e/xrij X-Gm-Gg: ASbGncspifZQoNfGMPffOL5ZzXb/G/vIX2R1cct8pDhmbTA9n8A7MsrGmDdrkpmlweD s0e6cNh2Gi1AHztdQNKJ9HqkmPw5/vRQnjaMCAw5qrjsqjHvcAPlX+Lgd+XDfsHSz24NipETL51 ynte70Sbz1Hrll7K9YAkWCsoiC90v22KkZ8Y8Eq4wkuJlguTmAcNOHoJvLyKMVNXllwP52eWHue HTBVbkWRALgAoX6hGbbyi2Wt3cQVfQE45ftsaITQ6VYCFbc5rQJ6d2HRbu2mbztC0lKUzgH/SLL dnL+8GH+o9F/BWQ= X-Received: by 2002:a17:907:e98a:b0:ad5:3a7b:de91 with SMTP id a640c23a62f3a-ad85b1bfa4amr972804166b.27.1748265160514; Mon, 26 May 2025 06:12:40 -0700 (PDT) X-Google-Smtp-Source: AGHT+IH8QvnLtVJhSpJ26PCw53K12teQU0kcApIkCEK6+L/O1mhz5DN4sVNTnhfSEoC9TKB9oRBNBA== X-Received: by 2002:a17:907:e98a:b0:ad5:3a7b:de91 with SMTP id a640c23a62f3a-ad85b1bfa4amr972799866b.27.1748265160087; Mon, 26 May 2025 06:12:40 -0700 (PDT) Received: from [10.40.98.122] ([78.108.130.194]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-ad52d04b059sm1702170766b.10.2025.05.26.06.12.39 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 26 May 2025 06:12:39 -0700 (PDT) Message-ID: Date: Mon, 26 May 2025 15:12:39 +0200 Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 2/4] media: Documentation: Add note about UVCH length field To: Ricardo Ribalda , Laurent Pinchart , Mauro Carvalho Chehab , Guennadi Liakhovetski Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org References: <20250404-uvc-meta-v5-0-f79974fc2d20@chromium.org> <20250404-uvc-meta-v5-2-f79974fc2d20@chromium.org> Content-Language: en-US, nl From: Hans de Goede In-Reply-To: <20250404-uvc-meta-v5-2-f79974fc2d20@chromium.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Hi, On 4-Apr-25 08:37, Ricardo Ribalda wrote: > The documentation currently describes the UVC length field as the "length > of the rest of the block", which can be misleading. The driver limits the > data copied to a maximum of 12 bytes. > > This change adds a clarifying sentence to the documentation to make this > restriction explicit. > > Signed-off-by: Ricardo Ribalda Thanks, patch looks good to me: Reviewed-by: Hans de Goede Regards, Hans > --- > Documentation/userspace-api/media/v4l/metafmt-uvc.rst | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/Documentation/userspace-api/media/v4l/metafmt-uvc.rst b/Documentation/userspace-api/media/v4l/metafmt-uvc.rst > index 784346d14bbdbf28348262084d5b0646d30bd1da..42599875331c0066cf529153caccb731148023b9 100644 > --- a/Documentation/userspace-api/media/v4l/metafmt-uvc.rst > +++ b/Documentation/userspace-api/media/v4l/metafmt-uvc.rst > @@ -44,7 +44,9 @@ Each individual block contains the following fields: > them > * - :cspan:`1` *The rest is an exact copy of the UVC payload header:* > * - __u8 length; > - - length of the rest of the block, including this field > + - length of the rest of the block, including this field. Please note that > + regardless of the this value, for V4L2_META_FMT_UVC the kernel will > + never copy more than 2-12 bytes. > * - __u8 flags; > - Flags, indicating presence of other standard UVC fields > * - __u8 buf[]; >