RE: [PATCH 1/1] mfd: omap-usb-host: Fix USB device detection problems on OMAP4 Panda

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



> From: Roger Quadros [mailto:rogerq@xxxxxx]
> On 11/29/2013 03:17 PM, David Laight wrote:
...
> >> +	timeout = jiffies + msecs_to_jiffies(100);
> >> +	while (!(usbhs_read(omap->uhh_base, OMAP_UHH_SYSSTATUS)
> >> +			& OMAP_UHH_SYSSTATUS_RESETDONE)) {
> >> +		cpu_relax();
> 
> You mean use msleep(1) here instead of cpu_relax()?
> Shouldn't be a problem IMO, but can you please tell me why that is better
> as the reset seems to complete usually in the first iteration.

If it doesn't finish in the first iteration you don't want to
spin the cpu for 100ms.

If it hasn't finished in the first millisecond, you probably expect
it to actually time out - so you might as well look (say) every 10ms.

	David



--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux Media]     [Linux Input]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Old Linux USB Devel Archive]

  Powered by Linux