From mboxrd@z Thu Jan 1 00:00:00 1970 From: Corey Minyard Subject: Re: [PATCH 1/3] misc: Add Aspeed BT IPMI host driver Date: Mon, 12 Sep 2016 15:33:57 -0500 Message-ID: <7db5ada0-49ea-55eb-089e-d979941ceff5@gmail.com> References: <1472664259-23933-1-git-send-email-clg@kaod.org> <1ce6c4b4-5938-22fc-7467-d1efc220b772@gmail.com> <4727554.yt7pF8chOH@wuerfel> Reply-To: minyard-HInyCGIudOg@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <4727554.yt7pF8chOH@wuerfel> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Arnd Bergmann , minyard-HInyCGIudOg@public.gmane.org Cc: Mark Rutland , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Jeremy Kerr , Andrew Jeffery , Alistair Popple , Russell King , Rob Herring , =?UTF-8?Q?C=c3=a9dric_Le_Goater?= , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Joel Stanley List-Id: devicetree@vger.kernel.org On 09/12/2016 02:15 PM, Arnd Bergmann wrote: > On Monday, September 12, 2016 1:55:40 PM CEST Corey Minyard wrote: >> On 09/02/2016 08:22 AM, Cédric Le Goater wrote: >>> Hello, >>> >>> Adding Corey in cc: . I guess I should have done that in the first place. >> Yes, probably so. I've been travelling and didn't see it on the mailing >> lists until now. >> >> There is already a BT driver in the kernel, in drivers/char/ipmi, why >> won't that work? > The new driver is the host side (running on the BMC), the existing one > is the client (running on the PC). > > Arnd Ok, that's not really clear from the documentation or the Kconfig. In the IPMI spec the "host" side is the computer side, not the BMC side. Like: 11.6.1 BT Host Interface Registers The Host BT interface provides an independent set of registers and interrupts to allow the Host driver to communicate with the baseboard management controller without conflicting with the O/S ACPI driver. In light of that, this should probably be named the bt-bmc driver. I haven't reviewed this in detail, but I'm ok with putting it in drivers/char/ipmi. The state machine part looks reasonably generic. The configuration part isn't, but that could be split out later if necessary. The biggest thing I don't like is the byte at a time interfaces from userspace. That seems fairly inefficient if the system does extra work for each userspace access. IIRC some systems do and some don't. -corey > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html