From: Michael Buesch <mb@bu3sch.de>
To: Harvey Harrison <harvey.harrison@gmail.com>
Subject: Re: [PATCHv2] b43: use the bitrev helpers rather than rolling a private one
Date: Wed, 14 May 2008 12:21:00 +0200
Cc: Andrew Morton <akpm@linux-foundation.org>,
	linux-wireless <linux-wireless@vger.kernel.org>
References: <1210708518.6191.0.camel@brick> <200805140303.23590.mb@bu3sch.de> <1210727615.6191.20.camel@brick>
In-Reply-To: <1210727615.6191.20.camel@brick>
MIME-Version: 1.0
Content-Type: text/plain;
  charset="iso-8859-15"
Message-Id: <200805141221.00979.mb@bu3sch.de> (sfid-20080514_122152_128623_FB2CF339)
Sender: linux-wireless-owner@vger.kernel.org

On Wednesday 14 May 2008 03:13:35 Harvey Harrison wrote:
> The 4-bit reversal flip_4bit is replaced with the bitrev helper
> bitrev8 and a 4-bit shift.  The B43_WARN is moved to the location
> where a register is read from for checking there.  The other caller
> explicitly passes an array index which is guaranteed to be within range
> and so a B43_WARN is not added there.
> 
> Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>

Reviewed-off-by: Michael Buesch <mb@bu3sch.de>

> ---
>  drivers/net/wireless/b43/phy.c |   27 ++++++---------------------
>  1 files changed, 6 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/net/wireless/b43/phy.c b/drivers/net/wireless/b43/phy.c
> index de024dc..feea79f 100644
> --- a/drivers/net/wireless/b43/phy.c
> +++ b/drivers/net/wireless/b43/phy.c
> @@ -28,6 +28,7 @@
>  #include <linux/delay.h>
>  #include <linux/io.h>
>  #include <linux/types.h>
> +#include <linux/bitrev.h>
>  
>  #include "b43.h"
>  #include "phy.h"
> @@ -83,25 +84,9 @@ const u8 b43_radio_channel_codes_bg[] = {
>  	72, 84,
>  };
>  
> +#define bitrev4(tmp) (bitrev8(tmp) >> 4)
>  static void b43_phy_initg(struct b43_wldev *dev);
>  
> -/* Reverse the bits of a 4bit value.
> - * Example:  1101 is flipped 1011
> - */
> -static u16 flip_4bit(u16 value)
> -{
> -	u16 flipped = 0x0000;
> -
> -	B43_WARN_ON(value & ~0x000F);
> -
> -	flipped |= (value & 0x0001) << 3;
> -	flipped |= (value & 0x0002) << 1;
> -	flipped |= (value & 0x0004) >> 1;
> -	flipped |= (value & 0x0008) >> 3;
> -
> -	return flipped;
> -}
> -
>  static void generate_rfatt_list(struct b43_wldev *dev,
>  				struct b43_rfatt_list *list)
>  {
> @@ -3069,13 +3054,13 @@ b43_radio_interference_mitigation_enable(struct b43_wldev *dev, int mode)
>  		}
>  		radio_stacksave(0x0078);
>  		tmp = (b43_radio_read16(dev, 0x0078) & 0x001E);
> -		flipped = flip_4bit(tmp);
> +		B43_WARN_ON(tmp > 15);
> +		flipped = bitrev4(tmp);
>  		if (flipped < 10 && flipped >= 8)
>  			flipped = 7;
>  		else if (flipped >= 10)
>  			flipped -= 3;
> -		flipped = flip_4bit(flipped);
> -		flipped = (flipped << 1) | 0x0020;
> +		flipped = (bitrev4(flipped) << 1) | 0x0020;
>  		b43_radio_write16(dev, 0x0078, flipped);
>  
>  		b43_calc_nrssi_threshold(dev);
> @@ -3708,7 +3693,7 @@ u16 b43_radio_init2050(struct b43_wldev *dev)
>  	tmp1 >>= 9;
>  
>  	for (i = 0; i < 16; i++) {
> -		radio78 = ((flip_4bit(i) << 1) | 0x20);
> +		radio78 = (bitrev4(i) << 1) | 0x0020;
>  		b43_radio_write16(dev, 0x78, radio78);
>  		udelay(10);
>  		for (j = 0; j < 16; j++) {


-- 
Greetings Michael.