Mark Lord wrote:
Jeff Garzik wrote:
Mark Lord wrote:
Tejun Heo wrote:
Hello, Mark.
Mark Lord wrote:
- /* now properly wait for the eDMA to stop */
- for (i = 1000; i > 0; i--) {
- reg = readl(port_mmio + EDMA_CMD_OFS);
+ /* Wait for the chip to confirm eDMA is off. */
+ for (i = 10000; i > 0; i--) {
+ u32 reg = readl(port_mmio + EDMA_CMD_OFS);
if (!(reg & EDMA_EN))
- break;
-
- udelay(100);
- }
-
- if (reg & EDMA_EN) {
- ata_port_printk(ap, KERN_ERR, "Unable to stop eDMA\n");
- err = -EIO;
+ return 0;
+ udelay(10);
Unless the hardware calls for really short polling interval, I think
it's generally better to limit polling with jiffies and using
msleep() instead of delays.
..
Oh, absolutely. I was just leaving Jeff's (?) original udelay() in
there
for now, to avoid another possible failure while testing the new stuff.
But if we can *guarantee* that .qc_issue and .port_stop are
always invoked only from thread context, then.. no problemo.
qc_issue is inside spin_lock_irqsave()
..
Okay, let's leave it alone for now.
Perhaps later it can be reworked again to find
a way to busy wait without messing up other stuff.
Nearly all of the time it exits rapidly anyway.
Aikk... right, it's called from the issue path too. In that case,
udelay() is the only way to go.
Thanks.
--
tejun
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