From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [PATCH 2/2] sata_sil: disable DMA engine in ->freeze Date: Wed, 08 Apr 2009 15:49:57 -0400 Message-ID: <49DCFFE5.7080807@garzik.org> References: <20090407232247.GA16086@havoc.gtf.org> <20090407232331.GA16190@havoc.gtf.org> <3fb94e50904072213n637525b1w4b032544dcef3618@mail.gmail.com> <49DC3357.3030703@garzik.org> <49DCFCEE.7040000@sutus.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from srv5.dvmed.net ([207.36.208.214]:51104 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1763555AbZDHTuH (ORCPT ); Wed, 8 Apr 2009 15:50:07 -0400 In-Reply-To: <49DCFCEE.7040000@sutus.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Dustin Harrison , Tejun Heo Cc: Sagar Borikar , linux-ide@vger.kernel.org, LKML , Alan Cox Dustin Harrison wrote: > Jeff Garzik wrote: >> Sagar Borikar wrote: >>> This patch works for our platform. >> >> Did you try both patches together? Both are required for the solution. >> > Thanks for updating the patch Jeff. I see you spotted the reason why I > didn't put the code into sil_freeze. I tested your patch and it > prevented the kernel panic. I now get the following output, which seems > to be correct to me. > > WARNING: at drivers/ata/libata-core.c:5209 ata_qc_complete() hum, my patch would indeed trigger this WARN_ON_ONCE() in ata_qc_complete(): if (ap->ops->error_handler) { struct ata_device *dev = qc->dev; struct ata_eh_info *ehi = &dev->link->eh_info; WARN_ON_ONCE(ap->pflags & ATA_PFLAG_FROZEN); Tejun, was that WARN_ON() originally added to detect spurious callers? Or, completions after the EH started? AFAICS, libata still owns the qc's at this point, so it should not be a problem to complete them when the port is frozen. Jeff > Call Trace: > [<80107ed0>] dump_stack+0x8/0x34 > [<802f92e0>] ata_qc_complete+0x58/0x114 > [<80303aec>] ata_port_abort+0xc4/0x104 > [<80306870>] sil_interrupt+0x340/0x384 > [<80146cc0>] handle_IRQ_event+0x54/0xb8 > [<80146dc0>] __do_IRQ+0x9c/0x11c > [<80102670>] ll_sutuspci_irq+0xe8/0x158 > [<8010161c>] do_extended_irq+0xa0/0x104 > [<80102b94>] ret_from_irq+0x0/0x4 > [<8029c4fc>] both_aligned+0x1c/0x64 > [<8014a9a4>] file_read_actor+0xac/0x154 > [<8014a564>] do_generic_mapping_read+0x210/0x5a4 > [<8014ce98>] generic_file_aio_read+0x180/0x1d4 > [<8016cba4>] do_sync_read+0xc4/0x128 > [<8016ccbc>] vfs_read+0xb4/0x154 > [<8016d02c>] sys_read+0x54/0x98 > [<8010a620>] stack_done+0x20/0x3c