Re: linux <=4.9.5, 4.10-rc7 ok, 4.9.6 - 4.9.8 nok with realtek wlan, atom

[rupert THURNER]

On Thu, Feb 9, 2017 at 9:09 PM, Larry Finger  wrote:
> On 02/09/2017 01:43 PM, Bjorn Helgaas wrote:
>>
>> [+cc rtl8192ce folks in case they've seen this]
>>
>> On Thu, Feb 09, 2017 at 03:45:01PM +0100, rupert THURNER wrote:
>>>
>>> hi,
>>>
>>> not technical expert enough, i just wanted to give a short user
>>> feedback. for realtek wlan on atom, kernels up to 4.9.5 are ok, and
>>> kernel 4.10.0-rc7-g926af6273fc6 (arch linux-git version numbering) as
>>> well. kernels 4.9.6, 4.9.7, and 4.9.8 fail, i.e. connection to a WLAN
>>> hotspot is possible then drops, or connecting to wlan fails
>>> alltogether.
>>
>>
>> Thanks very much for your report, and sorry for the inconvenience.
>>
>> v4.10-rc7 works, so I guess we don't need to worry about fixing v4.10.
>>
>> But the stable kernels v4.9.6, v4.9.7, and v4.9.8 are broken, so we
>> need to figure out why and make sure we fix the v4.9 stable series.
>>
>> I can't tell yet whether this is PCI-related or not.  If it is,
>> 4922a6a5cfa7 ("PCI: Enumerate switches below PCI-to-PCIe bridges")
>> appeared in v4.9.6, and there is a known issue with that.  The issue
>> should be fixed by 610c2b7ff8f6 ("PCI/ASPM: Handle PCI-to-PCIe bridges
>> as roots of PCIe hierarchies"), which appeared in v4.9.9, so I guess
>> the first thing to do would be to test v4.9.9.
>>
>> If it's not fixed in v4.9.9, can you share the complete dmesg log
>> (output of "dmesg" command) and "lspci -vv" output for v4.9.5 (last
>> known working version) and v4.9.6 (first known broken version)?  On
>> v4.9.6, collect the dmesg output after the failure occurs.
>
> It would be helpful if someone were to bisect this issue. The only issue
> that comes to mind was fixed in commit 52f5631a4c05 ("rtlwifi: rtl8192ce:
> Fix loading of incorrect firmware") which is in 4.10-rc7 and will be
> backported to 4.9.

thanks for the quick and very helpful hints! larry, it matches what
you write - 4.9.9 dropped the connection after a couple of hours.
lspci -vv is the same for 4.9.5 and 4.9.6. dmesg for both below. in
this case with 4.9.6 it did never get a network connection after boot.

$ sudo lspci -vv
00:00.0 Host bridge: Intel Corporation Atom Processor
D4xx/D5xx/N4xx/N5xx DMI Bridge (rev 02)
Subsystem: Intel Corporation Atom Processor D4xx/D5xx/N4xx/N5xx DMI Bridge
Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr-
Stepping- SERR- FastB2B- DisINTx-
Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort-
SERR- 
Kernel modules: intel_agp

00:1b.0 Audio device: Intel Corporation NM10/ICH7 Family High
Definition Audio Controller (rev 02)
Subsystem: Holco Enterprise Co, Ltd/Shuttle Computer Device 2005
Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr-
Stepping- SERR- FastB2B- DisINTx+
Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort-
SERR- TAbort-
SERR- TAbort-
Reset- FastB2B-
PriDiscTmr- SecDiscTmr- DiscTmrStat- DiscTmrSERREn-
Capabilities: [40] Express (v1) Root Port (Slot+), MSI 00
DevCap: MaxPayload 128 bytes, PhantFunc 0
ExtTag- RBE-
DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported-
RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop-
MaxPayload 128 bytes, MaxReadReq 128 bytes
DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr+ TransPend-
LnkCap: Port #1, Speed 2.5GT/s, Width x1, ASPM L0s L1, Exit Latency
L0s <256ns, L1 <4us
ClockPM- Surprise- LLActRep+ BwNot- ASPMOptComp-
LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- CommClk+
ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
LnkSta: Speed 2.5GT/s, Width x1, TrErr- Train- SlotClk+ DLActive+
BWMgmt- ABWMgmt-
SltCap: AttnBtn- PwrCtrl- MRL- AttnInd- PwrInd- HotPlug+ Surprise+
Slot #32, PowerLimit 10.000W; Interlock- NoCompl-
SltCtl: Enable: AttnBtn- PwrFlt- MRL- PresDet- CmdCplt- HPIrq- LinkChg-
Control: AttnInd Unknown, PwrInd Unknown, Power- Interlock-
SltSta: Status: AttnBtn- PowerFlt- MRL- CmdCplt- PresDet+ Interlock-
Changed: MRL- PresDet+ LinkState+
RootCtl: ErrCorrectable- ErrNon-Fatal- ErrFatal- PMEIntEna- CRSVisible-
RootCap: CRSVisible-
RootSta: PME ReqID , PMEStatus- PMEPending-
Capabilities: [80] MSI: Enable+ Count=1/1 Maskable- 64bit-
Address: fee0f00c  Data: 41a1
Capabilities: [90] Subsystem: Holco Enterprise Co, Ltd/Shuttle
Computer Device 2005
Capabilities: [a0] Power Management version 2
Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
Capabilities: [100 v1] Virtual Channel
Caps: LPEVC=0 RefClk=100ns PATEntryBits=1
Arb: Fixed+ WRR32- WRR64- WRR128-
Ctrl: ArbSelect=Fixed
Status: InProgress-
VC0: Caps: PATOffset=00 MaxTimeSlots=1 RejSnoopTrans-
Arb: Fixed+ WRR32- WRR64- WRR128- TWRR128- WRR256-
Ctrl: Enable+ ID=0 ArbSelect=Fixed TC/VC=01
Status: NegoPending- InProgress-
VC1: Caps: PATOffset=00 MaxTimeSlots=1 RejSnoopTrans-
Arb: Fixed+ WRR32- WRR64- WRR128- TWRR128- WRR256-
Ctrl: Enable- ID=0 ArbSelect=Fixed TC/VC=00
Status: NegoPending- InProgress-
Capabilities: [180 v1] Root 

Re: linux <=4.9.5, 4.10-rc7 ok, 4.9.6 - 4.9.8 nok with realtek wlan, atom

[Larry Finger]

On 02/09/2017 01:43 PM, Bjorn Helgaas wrote:

[+cc rtl8192ce folks in case they've seen this]

On Thu, Feb 09, 2017 at 03:45:01PM +0100, rupert THURNER wrote:

hi,

not technical expert enough, i just wanted to give a short user
feedback. for realtek wlan on atom, kernels up to 4.9.5 are ok, and
kernel 4.10.0-rc7-g926af6273fc6 (arch linux-git version numbering) as
well. kernels 4.9.6, 4.9.7, and 4.9.8 fail, i.e. connection to a WLAN
hotspot is possible then drops, or connecting to wlan fails
alltogether.


Thanks very much for your report, and sorry for the inconvenience.

v4.10-rc7 works, so I guess we don't need to worry about fixing v4.10.

But the stable kernels v4.9.6, v4.9.7, and v4.9.8 are broken, so we
need to figure out why and make sure we fix the v4.9 stable series.

I can't tell yet whether this is PCI-related or not.  If it is,
4922a6a5cfa7 ("PCI: Enumerate switches below PCI-to-PCIe bridges")
appeared in v4.9.6, and there is a known issue with that.  The issue
should be fixed by 610c2b7ff8f6 ("PCI/ASPM: Handle PCI-to-PCIe bridges
as roots of PCIe hierarchies"), which appeared in v4.9.9, so I guess
the first thing to do would be to test v4.9.9.

If it's not fixed in v4.9.9, can you share the complete dmesg log
(output of "dmesg" command) and "lspci -vv" output for v4.9.5 (last
known working version) and v4.9.6 (first known broken version)?  On
v4.9.6, collect the dmesg output after the failure occurs.


24: PCI 300.0: 0282 WLAN controller
  [Created at pci.366]
  Model: "Realtek RTL8188CE 802.11b/g/n WiFi Adapter"
  Device: pci 0x8176 "RTL8188CE 802.11b/g/n WiFi Adapter"
  Revision: 0x01
  Driver: "rtl8192ce"
  Driver Modules: "rtl8192ce"
  Device File: wlp3s0
  Features: WLAN


It would be helpful if someone were to bisect this issue. The only issue that 
comes to mind was fixed in commit 52f5631a4c05 ("rtlwifi: rtl8192ce: Fix loading 
of incorrect firmware") which is in 4.10-rc7 and will be backported to 4.9.


The above issue is one that could not be reproduced on my hardware, thus it took 
Jurij Smakov to find the fix. Without his bisection of the problem, who knows 
how long it would have taken to find my edit mistake.


Larry

Re: linux <=4.9.5, 4.10-rc7 ok, 4.9.6 - 4.9.8 nok with realtek wlan, atom

[Bjorn Helgaas]

[+cc rtl8192ce folks in case they've seen this]

On Thu, Feb 09, 2017 at 03:45:01PM +0100, rupert THURNER wrote:
> hi,
> 
> not technical expert enough, i just wanted to give a short user
> feedback. for realtek wlan on atom, kernels up to 4.9.5 are ok, and
> kernel 4.10.0-rc7-g926af6273fc6 (arch linux-git version numbering) as
> well. kernels 4.9.6, 4.9.7, and 4.9.8 fail, i.e. connection to a WLAN
> hotspot is possible then drops, or connecting to wlan fails
> alltogether.

Thanks very much for your report, and sorry for the inconvenience.

v4.10-rc7 works, so I guess we don't need to worry about fixing v4.10.

But the stable kernels v4.9.6, v4.9.7, and v4.9.8 are broken, so we
need to figure out why and make sure we fix the v4.9 stable series.

I can't tell yet whether this is PCI-related or not.  If it is,
4922a6a5cfa7 ("PCI: Enumerate switches below PCI-to-PCIe bridges")
appeared in v4.9.6, and there is a known issue with that.  The issue
should be fixed by 610c2b7ff8f6 ("PCI/ASPM: Handle PCI-to-PCIe bridges
as roots of PCIe hierarchies"), which appeared in v4.9.9, so I guess
the first thing to do would be to test v4.9.9.

If it's not fixed in v4.9.9, can you share the complete dmesg log
(output of "dmesg" command) and "lspci -vv" output for v4.9.5 (last
known working version) and v4.9.6 (first known broken version)?  On
v4.9.6, collect the dmesg output after the failure occurs.

> 24: PCI 300.0: 0282 WLAN controller
>   [Created at pci.366]
>   Model: "Realtek RTL8188CE 802.11b/g/n WiFi Adapter"
>   Device: pci 0x8176 "RTL8188CE 802.11b/g/n WiFi Adapter"
>   Revision: 0x01
>   Driver: "rtl8192ce"
>   Driver Modules: "rtl8192ce"
>   Device File: wlp3s0
>   Features: WLAN