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 6D4A31A08A4; Mon, 14 Apr 2025 09:32:25 +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=1744623145; cv=none; b=htjBTRylZzwKyQ3JosTvgjD1rMtW7Nmd7AvKD+AAg/4Rbbc3LxbFQpY5QQYBJQL/eo0i0GVP5N9EIvTZmAvWEgFmNPzC1i5Q2JU7PHn6WuxqL+CYTnsxmcIdWOxGI1x5LZAp08Z02FrlMd0EUyzMK32mG/coybY/n6qyi/FDbBA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744623145; c=relaxed/simple; bh=T1ricBvu6gD0hNKZi1AiodtjauiUrZN5jT9n8gpVu6I=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Rnsi9qcXs55FH2XLqA5kW7qOvRw0Zo0CSpbrgoZQpPulxkqhxgY2F7/17rOqkOdjCKwVEh2qNLUFPCvAMmokYFlI9x0GKJ6feTbGBRhk+pDamYZS64gsw1a4AVZKmDNXnYCeA1wPZtmR4fd8NgHF0TcV2Sq6RlDaSu7fpIvTHnY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=mg2hKdEf; 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="mg2hKdEf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6A64EC4CEE2; Mon, 14 Apr 2025 09:32:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1744623144; bh=T1ricBvu6gD0hNKZi1AiodtjauiUrZN5jT9n8gpVu6I=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=mg2hKdEfswh1uEbfFKcVkea0o7nleWjJCaWWjuta7AqdhErdkcgIOJatDhCzL9/sg kWBsfxz/cTmtxcgooYxPLuPjzRwAb8jYK360e+nFE1ThCQF541WV9witjuaswcuooi VaHXa0xUAX/WAJTvjwECZIWbjDbzL1FOi4k8Zuf4= Date: Mon, 14 Apr 2025 11:32:21 +0200 From: Greg KH To: Thierry Bultel Cc: Thierry Bultel , "linux-renesas-soc@vger.kernel.org" , "geert@linux-m68k.org" , Paul Barker , Wolfram Sang , "linux-kernel@vger.kernel.org" , "linux-serial@vger.kernel.org" Subject: Re: [PATCH v7 10/13] serial: sh-sci: Add support for RZ/T2H SCI Message-ID: <2025041458-squint-dean-9999@gregkh> References: <20250403212919.1137670-1-thierry.bultel.yh@bp.renesas.com> <20250403212919.1137670-11-thierry.bultel.yh@bp.renesas.com> <2025041152-puzzling-clinking-e573@gregkh> <2025041456-legacy-craftwork-2d8b@gregkh> Precedence: bulk X-Mailing-List: linux-serial@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 Mon, Apr 14, 2025 at 11:23:34AM +0200, Thierry Bultel wrote: > > > Le 14/04/2025 à 10:58, Greg KH a écrit : > > On Mon, Apr 14, 2025 at 07:54:12AM +0000, Thierry Bultel wrote: > > > Hi Greg, > > > > > > > -----Original Message----- > > > > From: Greg KH > > > > Sent: vendredi 11 avril 2025 16:57 > > > > To: Thierry Bultel > > > > Cc: thierry.bultel@linatsea.fr; linux-renesas-soc@vger.kernel.org; > > > > geert@linux-m68k.org; Paul Barker ; Wolfram > > > > Sang ; linux-kernel@vger.kernel.org; > > > > linux-serial@vger.kernel.org > > > > Subject: Re: [PATCH v7 10/13] serial: sh-sci: Add support for RZ/T2H SCI > > > > > > > > On Thu, Apr 03, 2025 at 11:29:12PM +0200, Thierry Bultel wrote: > > > > > --- a/include/uapi/linux/serial_core.h > > > > > +++ b/include/uapi/linux/serial_core.h > > > > > @@ -231,6 +231,9 @@ > > > > > /* Sunplus UART */ > > > > > #define PORT_SUNPLUS 123 > > > > > > > > > > +/* SH-SCI */ > > > > > +#define PORT_RSCI 124 > > > > Why do you need to tell userspace about this specific port? Is that a > > > > hard requirement that your userspace tools require? If not, please don't > > > > export this here. > > > This point has been discussed with Geert and Wolfram. > > > We cannot use PORT_GENERIC for this IP, and adding the new type > > > is just keeping consistent with the sh-sci driver. > > But, why does userspace need to know this number? And why doesn't > > PORT_GENERIC work? > > The reason is that the sh-sci driver discriminates internally between port > types. > There are number of locations when it checks for PORT_SCI, PORT_SCIF, > PORT_SCIFA... That is internal to the kernel, not external, right? > T2H SCI needs special handling, too, that is the reason why PORT_GENERIC > cannot work. I just therefore added this new type. Again, why does userspace need to know this? thanks, greg k-h