Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758667AbXI1D4r (ORCPT ); Thu, 27 Sep 2007 23:56:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753940AbXI1D4h (ORCPT ); Thu, 27 Sep 2007 23:56:37 -0400 Received: from rtr.ca ([76.10.145.34]:4451 "EHLO mail.rtr.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752506AbXI1D4g (ORCPT ); Thu, 27 Sep 2007 23:56:36 -0400 Message-ID: <46FC7B72.2030103@rtr.ca> Date: Thu, 27 Sep 2007 23:56:34 -0400 From: Mark Lord User-Agent: Thunderbird 2.0.0.6 (X11/20070728) MIME-Version: 1.0 To: Tejun Heo Cc: Jeff Garzik , Alan Cox , Andrew Morton , michal.k.k.piotrowski@gmail.com, bryan@arbores.ca, linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org Subject: [PATCH] libata drain fifo on stuck DRQ HSM violation References: <46CFA08E.6090604@arbores.ca> <6bffcb0e0708261610g10d9c59ck5789fac6feca9f42@mail.gmail.com> <46DBCB6C.8080206@gmail.com> <20070905095327.6277d054.akpm@linux-foundation.org> <46DEE617.4050004@rtr.ca> <46E0A253.7060803@gmail.com> <46E154DE.2060602@rtr.ca> <46FB563A.80108@gmail.com> <20070927193701.6230d77f@the-village.bc.nu> <46FC3D7D.90009@gmail.com> <46FC3FDD.5060201@pobox.com> <46FC423C.2050206@gmail.com> In-Reply-To: <46FC423C.2050206@gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2546 Lines: 70 Tejun Heo wrote: > Jeff Garzik wrote: >> Tejun Heo wrote: >>> Alan Cox wrote: >>>>> I think there have been enough cases where this draining was necessary. >>>>> IIRC, ata_piix was involved in those cases, right? If so, can you >>>>> please submit a patch which applies this only to affected controllers? >>>>> I don't feel too confident about applying this to all SFF controllers. >>>> Old IDE does it on all controllers bar a couple. So we have a very good >>>> knowledge of what does/doesn't work. The one that needs care in old ide >>>> is an ordering issue where a state machine reset done first causes the >>>> drain of the I/O to hang. >>> Hmmm... So, do we apply draining to all PATA? Or is ata_piix SATA >>> affected too? >> I would think all SFF controllers, since a lot of first gen SATA are >> really bridged solutions. If they are flagging DRQ, I say oblige them :) > > Alright, then the posted patch should be good enough. Mark, can you be > bothered to regenerate the patch and post it one more time (again)? It > seems we all agree the update is needed. I think this original patch still applies cleanly on at least 2.6.23-rc7. Drain up to 512 words from host/bridge FIFO on stuck DRQ HSM violation, rather than just getting stuck there forever. Signed-Off-By: Mark Lord --- --- old/drivers/ata/libata-sff.c 2007-04-26 12:02:46.000000000 -0400 +++ linux/drivers/ata/libata-sff.c 2007-04-29 08:29:27.000000000 -0400 @@ -413,6 +413,24 @@ ap->ops->irq_on(ap); } +static void ata_drain_fifo (struct ata_port *ap, struct ata_queued_cmd *qc) +{ + u8 stat = ata_chk_status(ap); + /* + * Try to clear stuck DRQ if necessary. + */ + if ((stat & ATA_DRQ) && (!qc || qc->dma_dir != DMA_TO_DEVICE)) { + unsigned int i, limit = 512; + printk("Draining up to %u words from data FIFO.\n", limit); + for (i = 0; i < limit ; ++i) { + ioread16(ap->ioaddr.data_addr); + if (!(ata_chk_status(ap) & ATA_DRQ)) + break; + } + printk("Drained %u/%u words.\n", i, limit); + } +} + /** * ata_bmdma_drive_eh - Perform EH with given methods for BMDMA controller * @ap: port to handle error for @@ -469,7 +487,7 @@ } ata_altstatus(ap); - ata_chk_status(ap); + ata_drain_fifo(ap, qc); ap->ops->irq_clear(ap); spin_unlock_irqrestore(ap->lock, flags); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/