mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-28 06:34:12 +08:00
sata_mv wait for empty+idle
When performing EH, it is recommended to wait for the EDMA engine to empty out requests-in-progress before disabling EDMA. Introduce code to poll the EDMA_STATUS register for idle/empty bits before disabling EDMA. For non-EH operation, this will normally exit without delay, other than the register read. A later series of patches may focus on eliminating this and various other register reads (when possible) throughout the driver, but for now we're focussing on solid reliablity. Signed-off-by: Mark Lord <mlord@pobox.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
This commit is contained in:
parent
616d4a98ad
commit
9b2c4e0bae
@ -888,6 +888,25 @@ static void mv_start_dma(struct ata_port *ap, void __iomem *port_mmio,
|
||||
}
|
||||
}
|
||||
|
||||
static void mv_wait_for_edma_empty_idle(struct ata_port *ap)
|
||||
{
|
||||
void __iomem *port_mmio = mv_ap_base(ap);
|
||||
const u32 empty_idle = (EDMA_STATUS_CACHE_EMPTY | EDMA_STATUS_IDLE);
|
||||
const int per_loop = 5, timeout = (15 * 1000 / per_loop);
|
||||
int i;
|
||||
|
||||
/*
|
||||
* Wait for the EDMA engine to finish transactions in progress.
|
||||
*/
|
||||
for (i = 0; i < timeout; ++i) {
|
||||
u32 edma_stat = readl(port_mmio + EDMA_STATUS_OFS);
|
||||
if ((edma_stat & empty_idle) == empty_idle)
|
||||
break;
|
||||
udelay(per_loop);
|
||||
}
|
||||
/* ata_port_printk(ap, KERN_INFO, "%s: %u+ usecs\n", __func__, i); */
|
||||
}
|
||||
|
||||
/**
|
||||
* mv_stop_edma_engine - Disable eDMA engine
|
||||
* @port_mmio: io base address
|
||||
@ -920,6 +939,7 @@ static int mv_stop_edma(struct ata_port *ap)
|
||||
if (!(pp->pp_flags & MV_PP_FLAG_EDMA_EN))
|
||||
return 0;
|
||||
pp->pp_flags &= ~MV_PP_FLAG_EDMA_EN;
|
||||
mv_wait_for_edma_empty_idle(ap);
|
||||
if (mv_stop_edma_engine(port_mmio)) {
|
||||
ata_port_printk(ap, KERN_ERR, "Unable to stop eDMA\n");
|
||||
return -EIO;
|
||||
|
Loading…
Reference in New Issue
Block a user