From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from d1.icnet.pl ([212.160.220.21]) by casper.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1SOv4y-0007Zs-2n for linux-mtd@lists.infradead.org; Mon, 30 Apr 2012 18:12:08 +0000 From: Janusz Krzysztofik To: Tony Lindgren Subject: Re: [PATCH v3.4-rc3] MTD: NAND: ams-delta: Fix request_mem_region() failure Date: Mon, 30 Apr 2012 20:09:54 +0200 Message-ID: <1520744.9xCxNUdyzk@acer> In-Reply-To: <1335417678.2290.7.camel@koala> References: <1334670557-25640-1-git-send-email-jkrzyszt@tis.icnet.pl> <1587089.0XMyH6e1Ic@acer> <1335417678.2290.7.camel@koala> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" 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: , 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? Thanks, Janusz