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authorDavid Milburn <dmilburn@redhat.com>2012-10-29 18:00:22 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-12-03 11:38:13 -0800
commit7e351dcf6764e9d6ab6c12efef6bace6eeeb2b36 (patch)
treeaca0e45067d024c1323a8682d81a2778efcaba82
parent2c531aa6d24cc8372c6aa4c0993309186dfb66af (diff)
downloadlinux-linaro-stable-7e351dcf6764e9d6ab6c12efef6bace6eeeb2b36.tar.gz
sata_svw: check DMA start bit before reset
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 <dmilburn@redhat.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com> Cc: CAI Qian <caiqian@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/ata/sata_svw.c35
1 files changed, 35 insertions, 0 deletions
diff --git a/drivers/ata/sata_svw.c b/drivers/ata/sata_svw.c
index 44a4256533e1..08608de87e4e 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,