From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from openfortress.nl ([213.189.19.244] helo=fame.vanrein.org) by bombadil.infradead.org with esmtp (Exim 4.69 #1 (Red Hat Linux)) id 1NF1ni-0006vf-J3 for linux-mtd@lists.infradead.org; Mon, 30 Nov 2009 08:40:10 +0000 Date: Mon, 30 Nov 2009 08:40:04 +0000 From: Rick van Rein To: linux-mtd@lists.infradead.org Subject: Flash I/O not enabled in MSR_DIVIL_BALL_OPTS Message-ID: <20091130084004.GE23351@phantom.vanrein.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hello, Thanks a lot for the detailed FAQ + documentation on the Linux MTD subsystem. It brought me from a novice on the Linux implementation to someone who feels in control. I am working to get a modest Linux distro going on what originally was a 7 Watt thin client running Win XPe. Since IDE is amazingly slow (it consumes 80% CPU time in IRQ handlers) I wanted to try direct access through JFFS2 to the NAND chips. Processor: Geode GX Chipset: Geode CS5535 NAND flash: Toshiba TC58DVM92A1FT00 (512 MB x8, a 3 to 5 of them) Controller: If there's a CompactFlash ctlr it is concealed from me Linux kernel: 2.6.31.6 without IDE but with CS553x NAND and JFFS2 When I boot this setup (over PXE), it reports: CS553x NAND controller: Flash I/O not enabled in MSR_DIVIL_BALL_OPTS Tracing this back in the code, this refers to an either-IDE-or-flash setting in the MSR that was either setup by RESET or the BIOS. The hardware works like that, the pins for IDE and NAND flash are multiplexed. I am not sure in XPe would see this, so if this flag is meaningful...? What surprised me was that the kernel contained no ways of setting this value to inform the NAND driver that it can play freely; is this because the hardware is wired purely for IDE operation? Or does the slow IDE responsiveness indicate that it is in fact flash, but not properly setup? Is there a proper way of setting this flag without patching the kernel? Thanks for any help you care to give, Cheers, Rick van Rein GroenGemak http://groengemak.nl/en/