linux-kernel - Re: [PATCH v2] Staging: dgnc: dgnc_*.c: Use usleep_range over udelay to improve coalescing processor wakeups

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Message-ID: <269ff7f4-c8f2-347e-835a-a5509bbb739a@exdev.nl>
Date:   Tue, 6 Dec 2016 11:01:48 +0100
From:   Shiva Kerdel <shiva@...ev.nl>
To:     Greg KH <gregkh@...uxfoundation.org>
Cc:     lidza.louina@...il.com, markh@...pro.net,
        driverdev-devel@...uxdriverproject.org, devel@...verdev.osuosl.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] Staging: dgnc: dgnc_*.c: Use usleep_range over udelay
 to improve coalescing processor wakeups


> On Tue, Dec 06, 2016 at 09:59:58AM +0100, Shiva Kerdel wrote:
>> In most cases, usleep_range is better than udelay, as the precise wakeup
>> from udelay is unnecessary.
> But, udelay does something different than usleep, are you sure you
> should be giving up the cpu at this point in time?
>
> Are you sure you are even in a function that is allowed to sleep?  I
> don't think that is the case for all of these at all, sorry, unless you
> have the hardware to test this change, I can't take it.
>
> greg k-h
I wasn't aware of this, thank you for pointing out.
Since I don't have this hardware, I'm unable to test the changes.

Shiva Kerdel