Re: [PATCH 2/2] dma: add Qualcomm Technologies HIDMA channel driver

[Sinan Kaya]

On 11/1/2015 3:21 PM, Timur Tabi wrote:
> Sinan Kaya wrote:
> > However, after issuing the command; I still need to wait some amount of
> > time until hardware acknowledges the commands like reset/enable/disable.
> > These are relatively faster operations happening in microseconds. That's
> > why, I have mdelay there.
>
> Can you use readl_poll_timeout()?
Yes, I'm changing them to readl_poll_timeout after looking at the 
workqueue vs. expected delay requirements. I decided to stick with 
polled read.

First, I missed the point here that mdelay is discouraged.
https://www.kernel.org/doc/Documentation/timers/timers-howto.txt

According to same document, msleep can sleep up to 20ms which is not 
what I want.

This code is trying to sleep 10ms maximum and treating longer durations 
as failures.

readl_poll_timeout calls usleep_range that seems to satisfy what I'm 
looking for.

--
Sinan Kaya
Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a 
Linux Foundation Collaborative Project
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/