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 3286C156236 for ; Wed, 28 Jan 2026 06:04:43 +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=1769580284; cv=none; b=F/p6/N/xbp6oOKkpF9SkbBxQRGv2If8NeoiJW81jKNU6X98bdsVdcOvzpaLOkYIeB3u/EL2b3IVfFSM5KAOGMSb8ynPrazwJFOujAwLJ2k9CSjO5HSjWeVhjBIFVxf+RDMcJi8j1ETPfzltpr3/Lq5flNUhQgDRfW9a+6VkqRiE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769580284; c=relaxed/simple; bh=1WSOXaTp3vSzGanQPvZAVSjeBc5Nczm4ReVDE1uCIzs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=XZh2zFfLNQhcaP0oYI5G85UpPX//P8zCcY1pZIilxaglCSFjrADaLHRU6/FwgEo/TYO9mGmkeFSZJ1p8vEQHEgJTI2oq1UdinVepYWmw/7IKHWUQaT4YNghxuX/Y9E/J3BiX0O8QT5IJMbDL0niDmyqCw/+P0WR4zVB968Uh7Bo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=hTNRGGAA; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="hTNRGGAA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 41ADEC4CEF1; Wed, 28 Jan 2026 06:04:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1769580283; bh=1WSOXaTp3vSzGanQPvZAVSjeBc5Nczm4ReVDE1uCIzs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=hTNRGGAAnPFOkmaPnEhb6GmnPzov4obSQRxDvLplsuac1YTZLdElO+Gmm2mKi6v53 6u067O3Ynsb4sYcJNSV2ax9rXRoWe3c6/mKh4qK+tzDkKkK5EAnS+rTbwnQhZThlPt N1SF7+5PFqnD2Gb8LXKFgACJ9eGbg3KMGLpvE6Ao= Date: Wed, 28 Jan 2026 07:04:40 +0100 From: Greg Kroah-Hartman To: Damien =?iso-8859-1?Q?Ri=E9gel?= Cc: greybus-dev@lists.linaro.org, linux-kernel@vger.kernel.org, Johan Hovold , Alex Elder , linux-devel@silabs.com Subject: Re: [PATCH 0/8] greybus: support point-to-point topology Message-ID: <2026012834-parrot-schilling-d4b0@gregkh> References: <20251223183142.31897-1-damien.riegel@silabs.com> <2026011606-qualified-dental-bef0@gregkh> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Tue, Jan 27, 2026 at 03:23:44PM -0500, Damien Riégel wrote: > On Fri Jan 16, 2026 at 10:09 AM EST, Greg Kroah-Hartman wrote: > [...] > > >> > >> The SVC doesn' really serve a purpose here, as there is no bus to > >> manage, and adding its support only increase the complexity and the code > >> size needed on memory-constrained devices. > > > > Exactly how much memory does a "single point" SVC driver take, vs. > > adding new P2P functionality everywhere in the code like you just did? > > Finding that out would be good first before worrying about adding > > another type of "bus" here please. > > Sorry for not giving numbers in the cover letter. We measured 10kB of > code size difference (which may be on the higher end of the spectrum) > and in Zephyr [1] they measured a 2kB difference (which is probably on > the lower end considering the implementation is pretty barebone). Please submit your "empty" SVC driver, 10kb seems too big to me, I think we can slim it down, or at the very least, see what is making it "large" and potentially work to reduce that. For Zephyr, I thought it was 1kb in the github comments, but still 2kb seems reasonable :) thanks, greg k-h