aboutsummaryrefslogtreecommitdiff
path: root/drivers/ata/libata-sff.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/ata/libata-sff.c')
-rw-r--r--drivers/ata/libata-sff.c45
1 files changed, 43 insertions, 2 deletions
diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index f93dc029dfd..9a10cb055ac 100644
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -52,6 +52,7 @@ const struct ata_port_operations ata_sff_port_ops = {
.softreset = ata_sff_softreset,
.hardreset = sata_sff_hardreset,
.postreset = ata_sff_postreset,
+ .drain_fifo = ata_sff_drain_fifo,
.error_handler = ata_sff_error_handler,
.post_internal_cmd = ata_sff_post_internal_cmd,
@@ -2199,6 +2200,39 @@ void ata_sff_postreset(struct ata_link *link, unsigned int *classes)
EXPORT_SYMBOL_GPL(ata_sff_postreset);
/**
+ * ata_sff_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 ata_sff_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 < 32768; count++)
+ ioread16(ap->ioaddr.data_addr);
+
+ /* Can become DEBUG later */
+ if (count)
+ ata_port_printk(ap, KERN_DEBUG,
+ "drained %d bytes to clear DRQ.\n", count);
+
+}
+EXPORT_SYMBOL_GPL(ata_sff_drain_fifo);
+
+/**
* ata_sff_error_handler - Stock error handler for BMDMA controller
* @ap: port to handle error for
*
@@ -2239,7 +2273,8 @@ void ata_sff_error_handler(struct ata_port *ap)
* really a timeout event, adjust error mask and
* cancel frozen state.
*/
- if (qc->err_mask == AC_ERR_TIMEOUT && (host_stat & ATA_DMA_ERR)) {
+ if (qc->err_mask == AC_ERR_TIMEOUT
+ && (host_stat & ATA_DMA_ERR)) {
qc->err_mask = AC_ERR_HOST_BUS;
thaw = 1;
}
@@ -2250,6 +2285,13 @@ void ata_sff_error_handler(struct ata_port *ap)
ata_sff_sync(ap); /* FIXME: We don't need this */
ap->ops->sff_check_status(ap);
ap->ops->sff_irq_clear(ap);
+ /* We *MUST* do FIFO draining before we issue a reset as several
+ * devices helpfully clear their internal state and will lock solid
+ * if we touch the data port post reset. Pass qc in case anyone wants
+ * to do different PIO/DMA recovery or has per command fixups
+ */
+ if (ap->ops->drain_fifo)
+ ap->ops->drain_fifo(qc);
spin_unlock_irqrestore(ap->lock, flags);
@@ -2959,4 +3001,3 @@ out:
EXPORT_SYMBOL_GPL(ata_pci_sff_init_one);
#endif /* CONFIG_PCI */
-