[PATCH] rtl8187: Remove deprecated 'qual' from returned RX status

[PATCH] rtl8187: Remove deprecated 'qual' from returned RX status

[Larry Finger]

The qual member of ieee80211_rx_status is deprecated. As a result, this
driver no longer needs to calculate a quality value.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
---

John,

This is 2.6.33 material.

Larry
---

Index: wireless-testing/drivers/net/wireless/rtl818x/rtl8187_dev.c
===================================================================
--- wireless-testing.orig/drivers/net/wireless/rtl818x/rtl8187_dev.c
+++ wireless-testing/drivers/net/wireless/rtl818x/rtl8187_dev.c
@@ -320,7 +320,6 @@ static void rtl8187_rx_cb(struct urb *ur
 	struct ieee80211_rx_status rx_status = { 0 };
 	int rate, signal;
 	u32 flags;
-	u32 quality;
 	unsigned long f;
 
 	spin_lock_irqsave(&priv->rx_queue.lock, f);
@@ -338,10 +337,9 @@ static void rtl8187_rx_cb(struct urb *ur
 			(typeof(hdr))(skb_tail_pointer(skb) - sizeof(*hdr));
 		flags = le32_to_cpu(hdr->flags);
 		/* As with the RTL8187B below, the AGC is used to calculate
-		 * signal strength and quality. In this case, the scaling
+		 * signal strength. In this case, the scaling
 		 * constants are derived from the output of p54usb.
 		 */
-		quality = 130 - ((41 * hdr->agc) >> 6);
 		signal = -4 - ((27 * hdr->agc) >> 6);
 		rx_status.antenna = (hdr->signal >> 7) & 1;
 		rx_status.mactime = le64_to_cpu(hdr->mac_time);
@@ -354,23 +352,18 @@ static void rtl8187_rx_cb(struct urb *ur
 		 * In testing, none of these quantities show qualitative
 		 * agreement with AP signal strength, except for the AGC,
 		 * which is inversely proportional to the strength of the
-		 * signal. In the following, the quality and signal strength
-		 * are derived from the AGC. The arbitrary scaling constants
+		 * signal. In the following, the signal strength
+		 * is derived from the AGC. The arbitrary scaling constants
 		 * are chosen to make the results close to the values obtained
 		 * for a BCM4312 using b43 as the driver. The noise is ignored
 		 * for now.
 		 */
 		flags = le32_to_cpu(hdr->flags);
-		quality = 170 - hdr->agc;
 		signal = 14 - hdr->agc / 2;
 		rx_status.antenna = (hdr->rssi >> 7) & 1;
 		rx_status.mactime = le64_to_cpu(hdr->mac_time);
 	}
 
-	if (quality > 100)
-		quality = 100;
-	rx_status.qual = quality;
-	priv->quality = quality;
 	rx_status.signal = signal;
 	priv->signal = signal;
 	rate = (flags >> 20) & 0xF;
Index: wireless-testing/drivers/net/wireless/rtl818x/rtl8187.h
===================================================================
--- wireless-testing.orig/drivers/net/wireless/rtl818x/rtl8187.h
+++ wireless-testing/drivers/net/wireless/rtl818x/rtl8187.h
@@ -119,7 +119,6 @@ struct rtl8187_priv {
 	} hw_rev;
 	struct sk_buff_head rx_queue;
 	u8 signal;
-	u8 quality;
 	u8 noise;
 	u8 slot_time;
 	u8 aifsn[4];

Re: [PATCH] rtl8187: Remove deprecated 'qual' from returned RX status

[Hin-Tak Leung]

On Thu, Nov 5, 2009 at 6:09 AM, Larry Finger <Larry.Finger@lwfinger.net> wrote:
> The qual member of ieee80211_rx_status is deprecated. As a result, this
> driver no longer needs to calculate a quality value.
>
> Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>

Acked-by: Hin-Tak Leung <htl10@users.sourceforge.net>

a bit busy lately. I'l give this a try soonest. BTW, well-done with
the oops on unplug.

Hin-Tak

> ---
>
> John,
>
> This is 2.6.33 material.
>
> Larry
> ---
>
> Index: wireless-testing/drivers/net/wireless/rtl818x/rtl8187_dev.c
> ===================================================================
> --- wireless-testing.orig/drivers/net/wireless/rtl818x/rtl8187_dev.c
> +++ wireless-testing/drivers/net/wireless/rtl818x/rtl8187_dev.c
> @@ -320,7 +320,6 @@ static void rtl8187_rx_cb(struct urb *ur
>        struct ieee80211_rx_status rx_status = { 0 };
>        int rate, signal;
>        u32 flags;
> -       u32 quality;
>        unsigned long f;
>
>        spin_lock_irqsave(&priv->rx_queue.lock, f);
> @@ -338,10 +337,9 @@ static void rtl8187_rx_cb(struct urb *ur
>                        (typeof(hdr))(skb_tail_pointer(skb) - sizeof(*hdr));
>                flags = le32_to_cpu(hdr->flags);
>                /* As with the RTL8187B below, the AGC is used to calculate
> -                * signal strength and quality. In this case, the scaling
> +                * signal strength. In this case, the scaling
>                 * constants are derived from the output of p54usb.
>                 */
> -               quality = 130 - ((41 * hdr->agc) >> 6);
>                signal = -4 - ((27 * hdr->agc) >> 6);
>                rx_status.antenna = (hdr->signal >> 7) & 1;
>                rx_status.mactime = le64_to_cpu(hdr->mac_time);
> @@ -354,23 +352,18 @@ static void rtl8187_rx_cb(struct urb *ur
>                 * In testing, none of these quantities show qualitative
>                 * agreement with AP signal strength, except for the AGC,
>                 * which is inversely proportional to the strength of the
> -                * signal. In the following, the quality and signal strength
> -                * are derived from the AGC. The arbitrary scaling constants
> +                * signal. In the following, the signal strength
> +                * is derived from the AGC. The arbitrary scaling constants
>                 * are chosen to make the results close to the values obtained
>                 * for a BCM4312 using b43 as the driver. The noise is ignored
>                 * for now.
>                 */
>                flags = le32_to_cpu(hdr->flags);
> -               quality = 170 - hdr->agc;
>                signal = 14 - hdr->agc / 2;
>                rx_status.antenna = (hdr->rssi >> 7) & 1;
>                rx_status.mactime = le64_to_cpu(hdr->mac_time);
>        }
>
> -       if (quality > 100)
> -               quality = 100;
> -       rx_status.qual = quality;
> -       priv->quality = quality;
>        rx_status.signal = signal;
>        priv->signal = signal;
>        rate = (flags >> 20) & 0xF;
> Index: wireless-testing/drivers/net/wireless/rtl818x/rtl8187.h
> ===================================================================
> --- wireless-testing.orig/drivers/net/wireless/rtl818x/rtl8187.h
> +++ wireless-testing/drivers/net/wireless/rtl818x/rtl8187.h
> @@ -119,7 +119,6 @@ struct rtl8187_priv {
>        } hw_rev;
>        struct sk_buff_head rx_queue;
>        u8 signal;
> -       u8 quality;
>        u8 noise;
>        u8 slot_time;
>        u8 aifsn[4];
> --
> To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>

Re: [PATCH] rtl8187: Remove deprecated 'qual' from returned RX status

[Michael Buesch]

On Thursday 05 November 2009 20:21:39 Hin-Tak Leung wrote:
> > +                * is derived from the AGC. The arbitrary scaling constants
> >                 * are chosen to make the results close to the values obtained
> >                 * for a BCM4312 using b43 as the driver. The noise is ignored

It's not really a good idea to take b43 for reference, because the values/scales
are chosen pretty arbitrarily in that driver. So you basically end up
with an arbitrary^2 value.

-- 
Greetings, Michael.

Re: [PATCH] rtl8187: Remove deprecated 'qual' from returned RX status

[Hin-Tak Leung]

On Thu, Nov 5, 2009 at 7:24 PM, Michael Buesch <mb@bu3sch.de> wrote:
> On Thursday 05 November 2009 20:21:39 Hin-Tak Leung wrote:
>> > +                * is derived from the AGC. The arbitrary scaling constants
>> >                 * are chosen to make the results close to the values obtained
>> >                 * for a BCM4312 using b43 as the driver. The noise is ignored
>
> It's not really a good idea to take b43 for reference, because the values/scales
> are chosen pretty arbitrarily in that driver. So you basically end up
> with an arbitrary^2 value.
>
> --
> Greetings, Michael.
>

Well, onee needs to start from something... many users, bug reporters
have often quoted 'I used driver/device X and it shows 90% strength,
yours shows 60%..." and vice versa. They don't know the numbers are
made up in both drivers, just differently :-).

Hin-Tak

Re: [PATCH] rtl8187: Remove deprecated 'qual' from returned RX status

[Larry Finger]

On 11/05/2009 01:24 PM, Michael Buesch wrote:
> On Thursday 05 November 2009 20:21:39 Hin-Tak Leung wrote:
>>> +                * is derived from the AGC. The arbitrary scaling constants
>>>                 * are chosen to make the results close to the values obtained
>>>                 * for a BCM4312 using b43 as the driver. The noise is ignored
> 
> It's not really a good idea to take b43 for reference, because the values/scales
> are chosen pretty arbitrarily in that driver. So you basically end up
> with an arbitrary^2 value.

When I did that, b43 was the only other device that I had available.
As Hin-Tak said, one has to start somewhere. As we all know, only
relative values are significant, and the absolute value has little
meaning.

Larry