Re: [ 57/72] genirq: Unmask oneshot irqs when thread was not woken

[Sven Joachim <svenjoac@gmx.de>]

Am 06.03.2012 um 20:45 schrieb Thomas Gleixner:

> On Mon, 5 Mar 2012, Stefan Lippers-Hollmann wrote:
>> On Monday 05 March 2012, Sven Joachim wrote:
>> > On 2012-02-28 02:05 +0100, Greg KH wrote:
>> > 
>> > > 3.2-stable review patch.  If anyone has any objections, please let me know.
>> > 
>> > Alas, the commit below broke the WiFi on my laptop, where
>> > "iwlist wlan0 scan" now just reports: " wlan0     No scan results".
>> > 
>> > This is not specific to 3.2, the same problem exists in 3.0.23 and
>> > 3.3-rc6 while previous releases worked.
>> 
>> I can confirm this regression on an old PIII based notebook with a 
>> 32 bit BCM4306/3 PCMCIA card:
>> 
>> 02:00.0 Network controller [0280]: Broadcom Corporation BCM4306 802.11b/g Wireless LAN Controller [14e4:4320] (rev 03)
>>         Subsystem: Linksys WPC54G v1 / WPC54GS v1 802.11g Wireless-G Notebook Adapter [1737:4320]
>>         Flags: bus master, fast devsel, latency 64, IRQ 10
>>         Memory at 20000000 (32-bit, non-prefetchable) [size=8K]
>>         Capabilities: [40] Power Management version 2
>>         Kernel driver in use: b43-pci-bridge
>> 
>> I can observe these differences in the dmesg output (3.2.9 + current 
>> stable queue-3.2):
>> 
>> The kernel configuration is identical in both cases, the only 
>> difference is "genirq: Unmask oneshot irqs when thread was not woken"
>> being applied or not.
>> 
>> --- working	<-- 3.2.9 + current stable queue-3.2, with "genirq: Unmask oneshot irqs when thread was not woken" reverted
>> +++ broken	<-- 3.2.9 + current stable queue-3.2
>> @@ -125,6 +125,7 @@ Initializing cgroup subsys freezer
>>  Initializing cgroup subsys net_cls
>>  Initializing cgroup subsys blkio
>>  Initializing cgroup subsys perf_event
>> +CPU serial number disabled.
>
> I can't see why reverting that genirq patch would cause this.
>
>>  mce: CPU supports 5 MCE banks
>>  SMP alternatives: switching to UP code
>>  Freeing SMP alternatives: 8k freed
>> @@ -137,9 +138,16 @@ SMP disabled
>>  Performance Events: 
>>  no APIC, boot with the "lapic" boot parameter to force-enable it.
>>  no hardware sampling interrupt available.
>> -Broken PMU hardware detected, using software events only.
>> +p6 PMU driver.
>> +... version:                0
>> +... bit width:              32
>> +... generic registers:      2
>> +... value mask:             00000000ffffffff
>> +... max period:             000000007fffffff
>> +... fixed-purpose events:   0
>> +... event mask:             0000000000000003
>
> Ditto.
>
>>  Brought up 1 CPUs
>>  Total of 1 processors activated (1989.75 BogoMIPS).
>>  devtmpfs: initialized
>>  PM: Registering ACPI NVS region at eeff000 (4096 bytes)
>>  print_constraints: dummy: 
>> @@ -174,12 +182,12 @@ pci 0000:00:00.0: reg 10: [mem 0xec00000
>>  type 1 class 0x000604
>>  pci 0000:00:01.0: supports D1
>>  type 2 class 0x000607
>> -pci 0000:00:04.0: reg 10: [mem 0x10000000-0x10000fff]
>> +pci 0000:00:04.0: reg 10: [mem 0x00000000-0x00000fff]
>
> Even more. 

FWIW, I don't see any such differences on my system (with 3.3-rc6).

> There is something extremly fishy.

Cheers,
       Sven