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| author | David Milburn <dmilburn@redhat.com> | 2012-10-29 18:00:22 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-12-03 12:59:15 -0800 |
| commit | a36eea2310e0b55c374cb97569e9311cef72dfd6 (patch) | |
| tree | a30065891454cd28b32be9135c71c284ef8a57e0 | |
| parent | 344b5bf8a586e53d129ea01c2c886c5814ec324b (diff) | |
| download | lwn-a36eea2310e0b55c374cb97569e9311cef72dfd6.tar.gz lwn-a36eea2310e0b55c374cb97569e9311cef72dfd6.zip | |
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.c | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/drivers/ata/sata_svw.c b/drivers/ata/sata_svw.c index 35eabcf34568..84980acf324e 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, |