Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Sun, 29 Mar 2020 11:28:33 +0200 (CEST)
From:   Julia Lawall <julia.lawall@inria.fr>
To:     "John B. Wyatt IV" <jbwyatt4@gmail.com>
cc:     outreachy-kernel@googlegroups.com,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Payal Kshirsagar <payal.s.kshirsagar.98@gmail.com>,
        dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org,
        devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org
Subject: Re: [Outreachy kernel] [PATCH] staging: fbtft: Replace udelay with
 preferred usleep_range
In-Reply-To: <20200329092204.770405-1-jbwyatt4@gmail.com>
Message-ID: <alpine.DEB.2.21.2003291127230.2990@hadrien>
References: <20200329092204.770405-1-jbwyatt4@gmail.com>
User-Agent: Alpine 2.21 (DEB 202 2017-01-01)
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


On Sun, 29 Mar 2020, John B. Wyatt IV wrote:

> Fix style issue with usleep_range being reported as preferred over
> udelay.
>
> Issue reported by checkpatch.
>
> Please review.
>
> As written in Documentation/timers/timers-howto.rst udelay is the
> generally preferred API. hrtimers, as noted in the docs, may be too
> expensive for this short timer.
>
> Are the docs out of date, or, is this a checkpatch issue?
>
> Signed-off-by: John B. Wyatt IV <jbwyatt4@gmail.com>
> ---
>  drivers/staging/fbtft/fb_agm1264k-fl.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/staging/fbtft/fb_agm1264k-fl.c b/drivers/staging/fbtft/fb_agm1264k-fl.c
> index eeeeec97ad27..019c8cce6bab 100644
> --- a/drivers/staging/fbtft/fb_agm1264k-fl.c
> +++ b/drivers/staging/fbtft/fb_agm1264k-fl.c
> @@ -85,7 +85,7 @@ static void reset(struct fbtft_par *par)
>  	dev_dbg(par->info->device, "%s()\n", __func__);
>
>  	gpiod_set_value(par->gpio.reset, 0);
> -	udelay(20);
> +	usleep_range(20, 20);

usleep_range should have a range, eg usleep_range(50, 100);.  But it is
hard to know a priori what the range should be.  So it is probably better
to leave the code alone.

julia

>  	gpiod_set_value(par->gpio.reset, 1);
>  	mdelay(120);
>  }
> --
> 2.25.1
>
> --
> You received this message because you are subscribed to the Google Groups "outreachy-kernel" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to outreachy-kernel+unsubscribe@googlegroups.com.
> To view this discussion on the web visit https://groups.google.com/d/msgid/outreachy-kernel/20200329092204.770405-1-jbwyatt4%40gmail.com.
>