From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mho-02-ewr.mailhop.org ([204.13.248.72]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1SQM2a-0003c2-U1 for linux-mtd@lists.infradead.org; Fri, 04 May 2012 17:11:37 +0000 Date: Fri, 4 May 2012 10:11:25 -0700 From: Tony Lindgren To: Janusz Krzysztofik Subject: Re: [PATCH v3.4-rc3] MTD: NAND: ams-delta: Fix request_mem_region() failure Message-ID: <20120504171125.GD5613@atomide.com> References: <1334670557-25640-1-git-send-email-jkrzyszt@tis.icnet.pl> <1587089.0XMyH6e1Ic@acer> <1335417678.2290.7.camel@koala> <1520744.9xCxNUdyzk@acer> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1520744.9xCxNUdyzk@acer> Cc: dedekind1@gmail.com, Artem Bityutskiy , linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, linux-omap@vger.kernel.org, David Woodhouse List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi, * Janusz Krzysztofik [120430 11:15]: > Dnia czwartek, 26 kwietnia 2012 08:20:59 Artem Bityutskiy pisze: > > On Wed, 2012-04-25 at 19:01 +0200, Janusz Krzysztofik wrote: > > > Both drivers use separate subsets of registers that belong to the > OMAP1 > > > MPU I/O device, but are used for controlling different sets of I/O > pins. > > > The NAND driver reads/writes the folowing registers: > > > - OMAP_MPUIO_INPUT_LATCH, > > > - OMAP_MPUIO_OUTPUT, > > > - OMAP_MPUIO_IO_CNTL, > > > while the keypad driver - the following: > > > - OMAP_MPUIO_KBR_LATCH, > > > - OMAP_MPUIO_KBC, > > > - OMAP_MPUIO_KBD_MASKIT > > > - OMAP_MPUIO_GPIO_DEBOUNCING. > > > Both subsets are non-overlapping, and we rely on the drivers being > free > > > of bugs and doing their job correctly, not stepping on each others' > > > feet, I guess. > > > > First of all, I think this information should be in the commit > message. > > Also, some sort of comment in the driver code would be nice. > > > > If locking the memory region is too coarse approach, the should have a > > small separate omap-specific MPUIO subsystem which will be used by > > drivers to access MPUIO? > > > > Another question - should request_mem_region() be also removed from > the > > omap-gpio driver then? I think it is more sensible to put a comment > > there that it is sharing MPIO with other drivers, instead of having > an > > illusion of exclusive memory region ownership. > > > > But this is up to the OMAP community - I can take this patch to my > > l2-mtd tree if you get an ack from Tony or other OMAP guys. > > Tony, > Would I get your Ack for this fix if I extend the commit message as Artem > suggested? If not, what do you think should be a correct way to fix the > regression? Well how about adding some exported functions to drivers/gpio/gpio_omap.c like omap_mpuio_latch? For the regression fix, if you guys want to do what Janusz is suggesting, then assuming the patch description also contains some decent long term plan to properly fix it: Acked-by: Tony Lindgren