From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754986Ab2L1UBL (ORCPT ); Fri, 28 Dec 2012 15:01:11 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:54859 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754160Ab2L1TQr (ORCPT ); Fri, 28 Dec 2012 14:16:47 -0500 Message-Id: <20121228190333.797385171@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Fri, 28 Dec 2012 20:03:48 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, David Milburn , Jeff Garzik Subject: [ 018/173] sata_svw: check DMA start bit before reset In-Reply-To: <20121228190330.025298996@decadent.org.uk> X-SA-Exim-Connect-IP: 151.217.219.220 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: David Milburn commit b03e66a6be91f8389fcd902ab6c1563db1c9c06b upstream. If kdump is triggered with pending IO, controller may not respond causing kdump to fail. http://marc.info/?l=linux-ide&m=133032255424658&w=2 During error recovery ata_do_dev_read_id never completes due hang in mmio_insw. ata_do_dev_read_id ata_sff_data_xfer ioread16_rep mmio_insw if DMA start bit is cleared before reset, PIO command is successful and kdump succeeds. Signed-off-by: David Milburn Signed-off-by: Jeff Garzik Signed-off-by: Ben Hutchings --- drivers/ata/sata_svw.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/drivers/ata/sata_svw.c b/drivers/ata/sata_svw.c index 44a4256..08608de 100644 --- a/drivers/ata/sata_svw.c +++ b/drivers/ata/sata_svw.c @@ -142,6 +142,39 @@ static int k2_sata_scr_write(struct ata_link *link, return 0; } +static int k2_sata_softreset(struct ata_link *link, + unsigned int *class, unsigned long deadline) +{ + u8 dmactl; + void __iomem *mmio = link->ap->ioaddr.bmdma_addr; + + dmactl = readb(mmio + ATA_DMA_CMD); + + /* Clear the start bit */ + if (dmactl & ATA_DMA_START) { + dmactl &= ~ATA_DMA_START; + writeb(dmactl, mmio + ATA_DMA_CMD); + } + + return ata_sff_softreset(link, class, deadline); +} + +static int k2_sata_hardreset(struct ata_link *link, + unsigned int *class, unsigned long deadline) +{ + u8 dmactl; + void __iomem *mmio = link->ap->ioaddr.bmdma_addr; + + dmactl = readb(mmio + ATA_DMA_CMD); + + /* Clear the start bit */ + if (dmactl & ATA_DMA_START) { + dmactl &= ~ATA_DMA_START; + writeb(dmactl, mmio + ATA_DMA_CMD); + } + + return sata_sff_hardreset(link, class, deadline); +} static void k2_sata_tf_load(struct ata_port *ap, const struct ata_taskfile *tf) { @@ -346,6 +379,8 @@ static struct scsi_host_template k2_sata_sht = { static struct ata_port_operations k2_sata_ops = { .inherits = &ata_bmdma_port_ops, + .softreset = k2_sata_softreset, + .hardreset = k2_sata_hardreset, .sff_tf_load = k2_sata_tf_load, .sff_tf_read = k2_sata_tf_read, .sff_check_status = k2_stat_check_status,