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: <20161206091222.GA12130@kroah.com>
Date:   Tue, 6 Dec 2016 10:12:22 +0100
From:   Greg KH <gregkh@...uxfoundation.org>
To:     Shiva Kerdel <shiva@...ev.nl>
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