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* Rate-setting problem with Broadcom 4315
@ 2009-10-25 18:55 Larry Finger
  2009-10-26  4:09 ` Felix Fietkau
  0 siblings, 1 reply; 3+ messages in thread
From: Larry Finger @ 2009-10-25 18:55 UTC (permalink / raw)
  To: wireless

When my BCM4312 (ID 4315) runs in auto rate mode, the rate stays at
1Mb/s. If I manually set the rate, I see a tcpperf throughput ~1/2 the
rate that I set through a rate of 12 Mb/s. At 36 Mb/s, the rate is
best at 15.7 Mb/s. Why does mistrel not increase the rate?

The output of /sys/..../rc_stats is:

finger@larrylap:~> cat
/sys/kernel/debug/ieee80211/phy0/stations/00:14:bf:85:49:fa/rc_stats
rate     throughput  ewma prob   this prob  this succ/attempt
success    attempts
     1         0.9       99.1      100.0          0(  0)       3244
     3282
     2         1.8       95.7      100.0          0(  0)         12
       12
     5.5       4.8       95.7      100.0          0(  0)         12
       12
    11         9.2       96.8      100.0          0(  0)         12
       12
  P  6         5.6       99.9      100.0          0(  0)         58
       58
     9         8.0       95.7      100.0          0(  0)         11
       11
    12        10.6       95.7      100.0          0(  0)         12
       12
    18        15.7       96.6      100.0          0(  0)         14
       15
    24        20.3       95.7      100.0          0(  0)         11
       11
    36        29.0       95.4       94.5          0(  0)       1602
     1670
T   48        38.7       99.2      100.0          1(  1)      32147
    37752
 t  54        32.9       75.9      100.0          0(  0)       8775
    12788

Total packet count::    ideal 2570      lookaround 135

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: Rate-setting problem with Broadcom 4315
  2009-10-25 18:55 Rate-setting problem with Broadcom 4315 Larry Finger
@ 2009-10-26  4:09 ` Felix Fietkau
  2009-10-26  5:39   ` Larry Finger
  0 siblings, 1 reply; 3+ messages in thread
From: Felix Fietkau @ 2009-10-26  4:09 UTC (permalink / raw)
  To: Larry Finger; +Cc: wireless

Larry Finger wrote:
> When my BCM4312 (ID 4315) runs in auto rate mode, the rate stays at
> 1Mb/s. If I manually set the rate, I see a tcpperf throughput ~1/2 the
> rate that I set through a rate of 12 Mb/s. At 36 Mb/s, the rate is
> best at 15.7 Mb/s. Why does mistrel not increase the rate?
> 
> The output of /sys/..../rc_stats is:
> 
> finger@larrylap:~> cat
> /sys/kernel/debug/ieee80211/phy0/stations/00:14:bf:85:49:fa/rc_stats
> rate     throughput  ewma prob   this prob  this succ/attempt
> success    attempts
>      1         0.9       99.1      100.0          0(  0)       3244
>      3282
>      2         1.8       95.7      100.0          0(  0)         12
>        12
>      5.5       4.8       95.7      100.0          0(  0)         12
>        12
>     11         9.2       96.8      100.0          0(  0)         12
>        12
>   P  6         5.6       99.9      100.0          0(  0)         58
>        58
>      9         8.0       95.7      100.0          0(  0)         11
>        11
>     12        10.6       95.7      100.0          0(  0)         12
>        12
>     18        15.7       96.6      100.0          0(  0)         14
>        15
>     24        20.3       95.7      100.0          0(  0)         11
>        11
>     36        29.0       95.4       94.5          0(  0)       1602
>      1670
> T   48        38.7       99.2      100.0          1(  1)      32147
>     37752
>  t  54        32.9       75.9      100.0          0(  0)       8775
>     12788
> 
> Total packet count::    ideal 2570      lookaround 135
Was this dump made after you played with manual rate settings? If so,
please make a new one that only contains stats of what it tried with
automatic rate setting enabled.

- Felix

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: Rate-setting problem with Broadcom 4315
  2009-10-26  4:09 ` Felix Fietkau
@ 2009-10-26  5:39   ` Larry Finger
  0 siblings, 0 replies; 3+ messages in thread
From: Larry Finger @ 2009-10-26  5:39 UTC (permalink / raw)
  To: Felix Fietkau; +Cc: wireless

Actually, the rate-setting mechanism is working. If I looked at the
iwconfig rate while a transmission was in progress, the rate toggled
between 48 and 54 Mb/s. When I checked between tests, it showed 1
Mb/s, which is what fooled me.

The rc_stats table is:

rate     throughput  ewma prob   this prob  this succ/attempt
success    attempts
  P  1         0.9       99.9      100.0          0(  0)        314
      314
     2         1.8       96.9      100.0          0(  0)         15
       16
     5.5       4.8       95.7      100.0          0(  0)         12
       12
    11         9.5       99.9      100.0          0(  0)        134
      138
     6         5.4       95.7      100.0          0(  0)         11
       11
     9         8.0       95.7      100.0          0(  0)         11
       11
    12        10.6       95.7      100.0          0(  0)         11
       11
    18        15.5       95.5      100.0          0(  0)         12
       13
    24        20.3       95.7      100.0          0(  0)         12
       12
    36        29.3       96.5       96.4          0(  0)       4118
     4249
T   48        37.6       96.3      100.0         23( 23)     376174
   414958
 t  54        36.8       84.8       81.5         62( 76)     356248
   427489

Total packet count::    ideal 6627      lookaround 348

The automatic throughput is about 13 Mb/s.

Larry


^ permalink raw reply	[flat|nested] 3+ messages in thread

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