On Sunday 05 August 2007, Larry Finger wrote: > Michael Buesch wrote: > > On Sunday 05 August 2007, Larry Finger wrote: > >> The link quality output from wireless extensions is too small by the ratio > >> of 100/BCM43xx_RX_MAX_SSI (60) for bcm43xx-mac80211. This patch puts the > >> quantity on the proper scale. > >> > >> Signed-off-by: Larry Finger <Larry.Finger@xxxxxxxxxxxx> > >> --- > >> > >> Index: wireless-dev/drivers/net/wireless/bcm43xx-mac80211/bcm43xx_xmit.c > >> =================================================================== > >> --- wireless-dev.orig/drivers/net/wireless/bcm43xx-mac80211/bcm43xx_xmit.c > >> +++ wireless-dev/drivers/net/wireless/bcm43xx-mac80211/bcm43xx_xmit.c > >> @@ -537,7 +537,8 @@ void bcm43xx_rx(struct bcm43xx_wldev *de > >> (phystat0 & BCM43xx_RX_PHYST0_GAINCTL), > >> (phystat3 & BCM43xx_RX_PHYST3_TRSTATE)); > >> status.noise = dev->stats.link_noise; > >> - status.signal = jssi; /* this looks wrong, but is what mac80211 wants */ > >> + /* the next line looks wrong, but is what mac80211 wants */ > >> + status.signal = (jssi * 100) / BCM43xx_RX_MAX_SSI; > > > > So signal is in percent? > > Where is this actually documented. I cannot find a hint on what > > the values of all these things are supposed to be. > > Yes, it is clear as mud, with the additional complications of mac80211 mixing the definitions of > signal and rssi (as far as I'm concerned). The scale is set by the following code snippet in > bcm43xx_wireless_init. > > hw->max_signal = 100; > hw->max_rssi = -110; > hw->max_noise = -110; > > In this code, "signal" is put on a scale of 0 to 100, and rssi and noise on a scale of -110 to 0 and > are assumed to be dBm. Of course, rssi should be a positive number and signal should be in dBm, but > my renaming of signal => quality and rssi => signal was shot down, so we are stuck. > > An alternative to the patch above would be to set hw->max_signal = BCM43xx_RX_MAX_SSI. In that case, > the line of iwconfig output that reads "Link Quality=83/100 Signal level=-34 dBm Noise level=-71 > dBm" would have a "Link Quality" of 50/60 instead of 83/100. > > The bottom line is that it is an arbitrary quantity on an arbitrary scale. Is it better for it to be > XX/100 than YY/60? I think so, but YMMV. Ah, I see. Kind of confusing. :) Well, I would like to do hw->max_signal = MAX_RSSI but it seems to be an unwritten rule that signal scales to 100. At least I never saw a different scale in a driver, yet. So I think I will apply your patch. Thanks! - To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
