[ 43/56] sata_svw: check DMA start bit before reset
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2012-11-30 19:00:09
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3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: David Milburn <redacted> 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 <redacted> Signed-off-by: Jeff Garzik <redacted> Cc: CAI Qian <redacted> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/ata/sata_svw.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+)
--- a/drivers/ata/sata_svw.c
+++ b/drivers/ata/sata_svw.c@@ -142,6 +142,39 @@ static int k2_sata_scr_write(struct ata_ 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 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,