From 3d47aa8e7e7b2aa09256590388aa8dddc79280f9 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Tue, 24 Mar 2009 10:23:19 +0000 Subject: [libata] Drain data on errors If the device is signalling that there is data to drain after an error we should read the bytes out and throw them away. Without this some devices and controllers get wedged and don't recover. Based on earlier work by Mark Lord Signed-off-by: Alan Cox Signed-off-by: Jeff Garzik --- drivers/ata/pata_pcmcia.c | 34 +++++++++++++++++++++++++++++++++- 1 file changed, 33 insertions(+), 1 deletion(-) (limited to 'drivers/ata/pata_pcmcia.c') diff --git a/drivers/ata/pata_pcmcia.c b/drivers/ata/pata_pcmcia.c index a5cbcc280b23..f4d009ed50ac 100644 --- a/drivers/ata/pata_pcmcia.c +++ b/drivers/ata/pata_pcmcia.c @@ -42,7 +42,7 @@ #define DRV_NAME "pata_pcmcia" -#define DRV_VERSION "0.3.3" +#define DRV_VERSION "0.3.5" /* * Private data structure to glue stuff together @@ -126,6 +126,37 @@ static unsigned int ata_data_xfer_8bit(struct ata_device *dev, return buflen; } +/** + * pcmcia_8bit_drain_fifo - Stock FIFO drain logic for SFF controllers + * @qc: command + * + * Drain the FIFO and device of any stuck data following a command + * failing to complete. In some cases this is neccessary before a + * reset will recover the device. + * + */ + +void pcmcia_8bit_drain_fifo(struct ata_queued_cmd *qc) +{ + int count; + struct ata_port *ap; + + /* We only need to flush incoming data when a command was running */ + if (qc == NULL || qc->dma_dir == DMA_TO_DEVICE) + return; + + ap = qc->ap; + + /* Drain up to 64K of data before we give up this recovery method */ + for (count = 0; (ap->ops->sff_check_status(ap) & ATA_DRQ) + && count++ < 65536;) + ioread8(ap->ioaddr.data_addr); + + if (count) + ata_port_printk(ap, KERN_WARNING, "drained %d bytes to clear DRQ.\n", + count); + +} static struct scsi_host_template pcmcia_sht = { ATA_PIO_SHT(DRV_NAME), @@ -143,6 +174,7 @@ static struct ata_port_operations pcmcia_8bit_port_ops = { .sff_data_xfer = ata_data_xfer_8bit, .cable_detect = ata_cable_40wire, .set_mode = pcmcia_set_mode_8bit, + .drain_fifo = pcmcia_8bit_drain_fifo, }; #define CS_CHECK(fn, ret) \ -- cgit v1.2.2