From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx149.postini.com [74.125.245.149]) by kanga.kvack.org (Postfix) with SMTP id B146A6B005D for ; Tue, 14 Aug 2012 20:25:48 -0400 (EDT) Date: Wed, 15 Aug 2012 03:25:36 +0300 From: Aaro Koskinen Subject: Re: Potential Regression in 3.6-rc1 - Kirkwood SATA Message-ID: <20120815002536.GC747@harshnoise.musicnaut.iki.fi> References: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Josh Coombs Cc: linux ARM , Andrew Lunn , m.szyprowski@samsung.com, linux-mm@kvack.org Him On Tue, Aug 14, 2012 at 07:59:00PM -0400, Josh Coombs wrote: > I finally got a chance to test 3.6-rc1 after having my GoFlex Net > support patch accepted for the 3.6 release train. Included in 3.6-rc1 > was an update for Kirkwoods switching SATA to DT which was not part of > my original testing. It seems something with this change has > partially broken the GoFlex and a couple other Kirkwood based devices. > > The key factor is the number of SATA ports defined in the dts: > > sata@80000 { > status = "okay"; > nr-ports = <2>; > }; > > If set at the correct number for my device, 2, my GFN does not > complete kernel init, hanging here: > > > [ 15.287832] Dquot-cache hash table entries: 1024 (order 0, 4096 bytes) > [ 15.296545] jffs2: version 2.2. (NAND) ?(C) 2001-2006 Red Hat, Inc. > [ 15.303202] msgmni has been set to 240 > [ 15.308503] Block layer SCSI generic (bsg) driver version 0.4 loaded (major ) > [ 15.316021] io scheduler noop registered > [ 15.320149] io scheduler deadline registered > [ 15.324558] io scheduler cfq registered (default) > [ 15.329462] mv_xor_shared mv_xor_shared.0: Marvell shared XOR driver > [ 15.335962] mv_xor_shared mv_xor_shared.1: Marvell shared XOR driver > [ 15.376751] mv_xor mv_xor.0: Marvell XOR: ( xor cpy ) > [ 15.416736] mv_xor mv_xor.1: Marvell XOR: ( xor fill cpy ) > [ 15.456735] mv_xor mv_xor.2: Marvell XOR: ( xor cpy ) > [ 15.496734] mv_xor mv_xor.3: Marvell XOR: ( xor fill cpy ) > [ 15.506309] Serial: 8250/16550 driver, 2 ports, IRQ sharing disabled > [ 15.509111] serial8250.0: ttyS0 at MMIO 0xf1012000 (irq = 33) is a 16550A > [ 15.509141] console [ttyS0] enabled, bootconsole disabled > [ 15.518967] brd: module loaded > [ 15.524991] loop: module loaded > [ 15.528584] sata_mv sata_mv.0: cannot get optional clkdev > [ 15.534180] sata_mv sata_mv.0: slots 32 ports 2 > > If you set nr-ports to 1 the unit boots cleanly, save for only > detecting one functional SATA port. Another user has confirmed this > behavior on an Iomega IX2-200. Try booting with "coherent_pool=1M" (or bigger) kernel parameter. I think with the recent DMA mapping changes, the default 256 KB coherent pool may be too small, mv_xor and sata_mv together needs more. (I'm not sure how it actually worked before commit e9da6e9905e639b0f842a244bc770b48ad0523e9, but it seems this is the cuase). It should be noted that dma_pool_alloc() uses GFP_ATOMIC always, and if drivers exhaust the coherent pool already during the boot that function just keeps looping forever. Users only see boot hanging with no clue what to do. I would say it's quite a poor error handling... A. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org