From: Calvin Walton <calvin.walton@kepstin.ca>
To: Christian Lamparter <chunkeey@googlemail.com>
Cc: linux-wireless@vger.kernel.org, linville@tuxdriver.com
Subject: Re: [PATCH] p54: Use do_div for 64-bit division to fix 32-bit kernels
Date: Wed, 07 Sep 2011 00:27:13 -0400 [thread overview]
Message-ID: <1315369635.3089.1.camel@ayu> (raw)
In-Reply-To: <201108252347.35706.chunkeey@googlemail.com>
On Thu, 2011-08-25 at 23:47 +0200, Christian Lamparter wrote:
> Use the do_div macro for 64-bit division. Otherwise, the module will
> reference __udivdi3 under 32-bit kernels, which is not allowed in
> kernel space.
>
> Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
> ---
> diff --git a/drivers/net/wireless/p54/txrx.c b/drivers/net/wireless/p54/txrx.c
> + do_div(survey->channel_time, 1024);
> + do_div(survey->channel_time_tx, 1024);
> + do_div(survey->channel_time_busy, 1024);
You're doing a division by a power of two here, why not just use a
bit-shift operation ">> 10" instead of a full division operation?
--
Calvin Walton <calvin.walton@kepstin.ca>
prev parent reply other threads:[~2011-09-07 4:27 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-25 21:47 [PATCH] p54: Use do_div for 64-bit division to fix 32-bit kernels Christian Lamparter
2011-09-07 4:27 ` Calvin Walton [this message]
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