rtlwifi (rtl8192ce) consistently reports EBUSY error, but scanning works

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* rtlwifi (rtl8192ce) consistently reports EBUSY error, but scanning works
@ 2014-03-05  6:36 Thierry Moreau
  2014-03-05  7:12 ` Larry Finger
  2014-03-05 10:51 ` Peter Wu
  0 siblings, 2 replies; 10+ messages in thread
From: Thierry Moreau @ 2014-03-05  6:36 UTC (permalink / raw)
  To: linux-wireless

Hi!

I am using a kind-of "linux from scratch" (i.e. Crux 3.0, 64 bits Intel, 
kernel 3.10.32) and I am stuck with a EBUSY error return from the 
wireless driver I suspect it comes from the driver behavior since it is 
consistent either from the command

iw dev wlan1 set channel 2

or the comand

iwconfig wlan1 set channel 2

(it occurred also with "iw" with a kernel where the iwconfig support 
emulation is off -- CONFIG_CFG82011_WEXT). The EBUSY error return occurs 
as early as immediately after the initial module install, and 
consistently thereafter. The wireless scanning works (reporting a nearby 
beacon on channel 1).

I understand this list is not for user/integrator support but since I 
control many variables in the troubleshooting exercise, some of you 
might be interested in finding more about a possible bug.

Here is a sequence of commands immediately after system boot:

+ uname -a
Linux a-host 3.10.32 #2 SMP Wed Mar 5 00:39:47 UTC 2014 x86_64 Intel(R) 
Atom(TM) CPU D2550 @ 1.86GHz GenuineIntel GNU/Linux

+ dmesg | grep -i wifi -C 4 -n
853-[    2.468354] gma500 0000:00:02.0: trying to get vblank count for 
disabled pipe 1
854-[    2.556398] usb 5-2: new low-speed USB device number 2 using uhci_hcd
855-[    2.685093] rtl8192ce:_rtl92ce_read_chip_version():<0-0> Chip 
Version ID: B_CUT_88C
856-[    2.693197] fbcon: psbdrmfb (fb0) is primary device
857:[    2.697204] rtl8192ce: Using firmware rtlwifi/rtl8192cfwU_B.bin
858-[    2.700363] modprobe (109) used greatest stack depth: 3928 bytes left
859-[    2.700499] usb 5-2: skipped 1 descriptor after interface
860-[    2.700506] usb 5-2: skipped 1 descriptor after interface
861-[    2.705486] usb 5-2: default language 0x0409
--
889-[    3.149779] gma500 0000:00:02.0: fb0: psbdrmfb frame buffer device
890-[    3.149784] gma500 0000:00:02.0: registered panic notifier
891-[    3.149870] [drm] Initialized gma500 1.0.0 2011-06-06 for 
0000:00:02.0 on minor 0
892-[    3.403646] ieee80211 phy0: Selected rate control algorithm 'rtl_rc'
893:[    3.404050] rtlwifi: wireless switch is on
894-[    5.579389] Adding 16777212k swap on /dev/sda6.  Priority:42 
extents:1 across:16777212k
895-[    5.595963] Adding 16777212k swap on /dev/sda7.  Priority:52 
extents:1 across:16777212k
896-[    5.611337] Adding 16777212k swap on /dev/sda8.  Priority:62 
extents:1 across:16777212k
897-[    5.699807] rm (146) used greatest stack depth: 3032 bytes left

+ lsmod
Module                  Size  Used by
rtl8192ce              72128  0
gma500_gfx            147187  1
rtlwifi               106604  1 rtl8192ce
rtl8192c_common        54252  1 rtl8192ce
drm_kms_helper         27871  1 gma500_gfx

+ iwconfig
eth0      no wireless extensions.

lo        no wireless extensions.

sit0      no wireless extensions.

wlan1     IEEE 802.11bgn  ESSID:off/any
           Mode:Managed  Access Point: Not-Associated   Tx-Power=0 dBm
           Retry  long limit:7   RTS thr=2347 B   Fragment thr:off
           Encryption key:off
           Power Management:on

+ iw dev wlan1 info
Interface wlan1
	ifindex 4
	wdev 0x1
	addr 64:5a:04:aa:f8:16
	type managed
	wiphy 0

**** Here is the first occurrence of the blocking error condition:

+ iw dev wlan1 set channel 2
command failed: Device or resource busy (-16)

**** Next error is expected:

+ iw dev wlan1 scan
command failed: Network is down (-100)

+ ip link set up wlan1

+ iw dev wlan1 scan
BSS d8:6c:e9:29:e5:75(on wlan1)
	TSF: 1305304974530 usec (15d, 02:35:04)
	freq: 2412
... bla bla bla
		 * Device name: RalinkAPS
		 * Config methods: Label, PBC
		 * RF Bands: 0x1

+ iwlist wlan1 scanning
wlan1     Scan completed :
           Cell 01 - Address: D8:6C:E9:29:E5:75
                     Channel:1
                     Frequency:2.412 GHz (Channel 1)
                     Quality=70/70  Signal level=-4 dBm
... bla bla bla
                     IE: Unknown: 0706434120010B10

**** Here is another instance of the blocking error condition (occurs 
with iw as well):

+ iwconfig wlan1 channel 2
Error for wireless request "Set Frequency" (8B04) :
     SET failed on device wlan1 ; Device or resource busy.

**** Some user of a widespread distribution reported a similar problem 
and a work-around with the "iw ... interface add .." command, which I 
attempt here:

+ ip link set down wlan1

+ iw dev wlan1 interface add wlan2 type managed

**** note that I don't care that the name wlan2 turns into rename5 
because it did not occur without CONFIG_CFG82011_WEXT which is useless 
besides the present troubleshooting:

+ iwconfig
eth0      no wireless extensions.

lo        no wireless extensions.

sit0      no wireless extensions.

wlan1     IEEE 802.11bgn  ESSID:off/any
           Mode:Managed  Frequency:2.417 GHz  Access Point: 
Not-Associated
           Tx-Power=20 dBm
           Retry  long limit:7   RTS thr=2347 B   Fragment thr:off
           Encryption key:off
           Power Management:off

rename5   IEEE 802.11bgn  ESSID:off/any
           Mode:Managed  Access Point: Not-Associated   Tx-Power=20 dBm
           Retry  long limit:7   RTS thr=2347 B   Fragment thr:off
           Encryption key:off
           Power Management:on

**** Too bad it occurs again:

+ iw dev rename5 set channel 2
command failed: Device or resource busy (-16)

==============

Final remarks:

I went through the firmware load learning curve for a Linux 
user/integrator and I am confident that the following sha1sum'ed file 
has been loaded:
c81ec289a236875ab7139c0e357fdcddcc21cc46 
/lib/firmware/rtlwifi/rtl8192cfwU_B.bin
(the fact that scanning works supports my confidence)

I investigated the iw source code (version 3.11, but the above is with 
version 3.14) and I gave up once I traced the reported error condition 
to the call to nl_recvmsgs in the iw.c source file.

I grep'ed EBUSY in the C source files in the drivers/net/rtlwifi 
sub-directories and find none. I suppose some other component in the 
driver detects the error condition.

If I recall correctly, the command "iw ... interface add ..." followed 
by "iw ... del" for the source interface allowed me to set the channel 
without the EBUSY outcome once (and the sticky EBUSY came again vey 
soon) with the kernel devoid of CONFIG_CFG82011_WEXT. It makes seldom 
sense to me to pursue this elusive workaround, but this could be a sign 
that a fresh kernel "interface" data structure turns EBUSY-sick after 
some action occurring in the driver initialization logic.

The system is a Shuttle XS36VL box 
(http://us.shuttle.com/barebone/Models/XS36VL.html). It does not have a 
physical wireless switch (a dmesg line above reports the switch position 
as "on").

Any suggestion about a next step in troubleshooting? Maybe trying the 
latest kernel release candidate?

Thanks for your attention.

-- Thierry Moreau

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: rtlwifi (rtl8192ce) consistently reports EBUSY error, but scanning works
  2014-03-05  6:36 rtlwifi (rtl8192ce) consistently reports EBUSY error, but scanning works Thierry Moreau
@ 2014-03-05  7:12 ` Larry Finger
  2014-03-05 16:27   ` Thierry Moreau
  2014-03-05 10:51 ` Peter Wu
  1 sibling, 1 reply; 10+ messages in thread
From: Larry Finger @ 2014-03-05  7:12 UTC (permalink / raw)
  To: Thierry Moreau, linux-wireless

On 03/05/2014 12:36 AM, Thierry Moreau wrote:
> Hi!
>
> I am using a kind-of "linux from scratch" (i.e. Crux 3.0, 64 bits Intel, kernel
> 3.10.32) and I am stuck with a EBUSY error return from the wireless driver I
> suspect it comes from the driver behavior since it is consistent either from the
> command
>
> iw dev wlan1 set channel 2
>
> or the comand
>
> iwconfig wlan1 set channel 2
>
> (it occurred also with "iw" with a kernel where the iwconfig support emulation
> is off -- CONFIG_CFG82011_WEXT). The EBUSY error return occurs as early as
> immediately after the initial module install, and consistently thereafter. The
> wireless scanning works (reporting a nearby beacon on channel 1).
>
> I understand this list is not for user/integrator support but since I control
> many variables in the troubleshooting exercise, some of you might be interested
> in finding more about a possible bug.
>
> Here is a sequence of commands immediately after system boot:
>
> + uname -a
> Linux a-host 3.10.32 #2 SMP Wed Mar 5 00:39:47 UTC 2014 x86_64 Intel(R) Atom(TM)
> CPU D2550 @ 1.86GHz GenuineIntel GNU/Linux
>
> + dmesg | grep -i wifi -C 4 -n
> 853-[    2.468354] gma500 0000:00:02.0: trying to get vblank count for disabled
> pipe 1
> 854-[    2.556398] usb 5-2: new low-speed USB device number 2 using uhci_hcd
> 855-[    2.685093] rtl8192ce:_rtl92ce_read_chip_version():<0-0> Chip Version ID:
> B_CUT_88C
> 856-[    2.693197] fbcon: psbdrmfb (fb0) is primary device
> 857:[    2.697204] rtl8192ce: Using firmware rtlwifi/rtl8192cfwU_B.bin
> 858-[    2.700363] modprobe (109) used greatest stack depth: 3928 bytes left
> 859-[    2.700499] usb 5-2: skipped 1 descriptor after interface
> 860-[    2.700506] usb 5-2: skipped 1 descriptor after interface
> 861-[    2.705486] usb 5-2: default language 0x0409
> --
> 889-[    3.149779] gma500 0000:00:02.0: fb0: psbdrmfb frame buffer device
> 890-[    3.149784] gma500 0000:00:02.0: registered panic notifier
> 891-[    3.149870] [drm] Initialized gma500 1.0.0 2011-06-06 for 0000:00:02.0 on
> minor 0
> 892-[    3.403646] ieee80211 phy0: Selected rate control algorithm 'rtl_rc'
> 893:[    3.404050] rtlwifi: wireless switch is on
> 894-[    5.579389] Adding 16777212k swap on /dev/sda6.  Priority:42 extents:1
> across:16777212k
> 895-[    5.595963] Adding 16777212k swap on /dev/sda7.  Priority:52 extents:1
> across:16777212k
> 896-[    5.611337] Adding 16777212k swap on /dev/sda8.  Priority:62 extents:1
> across:16777212k
> 897-[    5.699807] rm (146) used greatest stack depth: 3032 bytes left
>
> + lsmod
> Module                  Size  Used by
> rtl8192ce              72128  0
> gma500_gfx            147187  1
> rtlwifi               106604  1 rtl8192ce
> rtl8192c_common        54252  1 rtl8192ce
> drm_kms_helper         27871  1 gma500_gfx
>
> + iwconfig
> eth0      no wireless extensions.
>
> lo        no wireless extensions.
>
> sit0      no wireless extensions.
>
> wlan1     IEEE 802.11bgn  ESSID:off/any
>            Mode:Managed  Access Point: Not-Associated   Tx-Power=0 dBm
>            Retry  long limit:7   RTS thr=2347 B   Fragment thr:off
>            Encryption key:off
>            Power Management:on
>
>
> + iw dev wlan1 info
> Interface wlan1
>      ifindex 4
>      wdev 0x1
>      addr 64:5a:04:aa:f8:16
>      type managed
>      wiphy 0
>
> **** Here is the first occurrence of the blocking error condition:
>
> + iw dev wlan1 set channel 2
> command failed: Device or resource busy (-16)
>
> **** Next error is expected:
>
> + iw dev wlan1 scan
> command failed: Network is down (-100)
>
> + ip link set up wlan1
>
> + iw dev wlan1 scan
> BSS d8:6c:e9:29:e5:75(on wlan1)
>      TSF: 1305304974530 usec (15d, 02:35:04)
>      freq: 2412
> ... bla bla bla
>           * Device name: RalinkAPS
>           * Config methods: Label, PBC
>           * RF Bands: 0x1
>
> + iwlist wlan1 scanning
> wlan1     Scan completed :
>            Cell 01 - Address: D8:6C:E9:29:E5:75
>                      Channel:1
>                      Frequency:2.412 GHz (Channel 1)
>                      Quality=70/70  Signal level=-4 dBm
> ... bla bla bla
>                      IE: Unknown: 0706434120010B10
>
>
> **** Here is another instance of the blocking error condition (occurs with iw as
> well):
>
> + iwconfig wlan1 channel 2
> Error for wireless request "Set Frequency" (8B04) :
>      SET failed on device wlan1 ; Device or resource busy.
>
> **** Some user of a widespread distribution reported a similar problem and a
> work-around with the "iw ... interface add .." command, which I attempt here:
>
> + ip link set down wlan1
>
> + iw dev wlan1 interface add wlan2 type managed
>
> **** note that I don't care that the name wlan2 turns into rename5 because it
> did not occur without CONFIG_CFG82011_WEXT which is useless besides the present
> troubleshooting:
>
> + iwconfig
> eth0      no wireless extensions.
>
> lo        no wireless extensions.
>
> sit0      no wireless extensions.
>
> wlan1     IEEE 802.11bgn  ESSID:off/any
>            Mode:Managed  Frequency:2.417 GHz  Access Point: Not-Associated
>            Tx-Power=20 dBm
>            Retry  long limit:7   RTS thr=2347 B   Fragment thr:off
>            Encryption key:off
>            Power Management:off
>
> rename5   IEEE 802.11bgn  ESSID:off/any
>            Mode:Managed  Access Point: Not-Associated   Tx-Power=20 dBm
>            Retry  long limit:7   RTS thr=2347 B   Fragment thr:off
>            Encryption key:off
>            Power Management:on
>
> **** Too bad it occurs again:
>
> + iw dev rename5 set channel 2
> command failed: Device or resource busy (-16)
>
>
> ==============
>
> Final remarks:
>
> I went through the firmware load learning curve for a Linux user/integrator and
> I am confident that the following sha1sum'ed file has been loaded:
> c81ec289a236875ab7139c0e357fdcddcc21cc46 /lib/firmware/rtlwifi/rtl8192cfwU_B.bin
> (the fact that scanning works supports my confidence)
>
> I investigated the iw source code (version 3.11, but the above is with version
> 3.14) and I gave up once I traced the reported error condition to the call to
> nl_recvmsgs in the iw.c source file.
>
> I grep'ed EBUSY in the C source files in the drivers/net/rtlwifi sub-directories
> and find none. I suppose some other component in the driver detects the error
> condition.
>
> If I recall correctly, the command "iw ... interface add ..." followed by "iw
> ... del" for the source interface allowed me to set the channel without the
> EBUSY outcome once (and the sticky EBUSY came again vey soon) with the kernel
> devoid of CONFIG_CFG82011_WEXT. It makes seldom sense to me to pursue this
> elusive workaround, but this could be a sign that a fresh kernel "interface"
> data structure turns EBUSY-sick after some action occurring in the driver
> initialization logic.
>
> The system is a Shuttle XS36VL box
> (http://us.shuttle.com/barebone/Models/XS36VL.html). It does not have a physical
> wireless switch (a dmesg line above reports the switch position as "on").
>
> Any suggestion about a next step in troubleshooting? Maybe trying the latest
> kernel release candidate?

I use NetworkManager and I never see errors like this.

You definitely should use either a newer kernel or the backports sources. There 
is a recent change that fixes a problem in rtl8192ce that caused interrupts to 
be disabled for a long time. That fix is in the mainline 3.14-rc5 and in the 
wireless-testing repo. It is in the process of being applied to the various 
stable kernels, but it is probably not there yet.

If you just want to try that patch, it is available at 
https://lkml.org/lkml/2014/2/1/15.

Larry



^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: rtlwifi (rtl8192ce) consistently reports EBUSY error, but scanning works
  2014-03-05  7:12 ` Larry Finger
@ 2014-03-05 16:27   ` Thierry Moreau
  2014-03-05 16:40     ` Larry Finger
  0 siblings, 1 reply; 10+ messages in thread
From: Thierry Moreau @ 2014-03-05 16:27 UTC (permalink / raw)
  To: Larry Finger, linux-wireless

On 03/05/14 07:12, Larry Finger wrote:
> On 03/05/2014 12:36 AM, Thierry Moreau wrote:
>> Hi!
>>
>> I am using a kind-of "linux from scratch" (i.e. Crux 3.0, 64 bits
>> Intel, kernel
>> 3.10.32) and I am stuck with a EBUSY error return from the wireless
>> driver I
>> suspect it comes from the driver behavior since it is consistent
>> either from the
>> command
>>
>> iw dev wlan1 set channel 2
>>
>> or the comand
>>
>> iwconfig wlan1 set channel 2
>>
>> (it occurred also with "iw" with a kernel where the iwconfig support
>> emulation
>> is off -- CONFIG_CFG82011_WEXT). The EBUSY error return occurs as
>> early as
>> immediately after the initial module install, and consistently
>> thereafter. The
>> wireless scanning works (reporting a nearby beacon on channel 1).

>>  [ ... ... ]

>>
>> Any suggestion about a next step in troubleshooting? Maybe trying the
>> latest
>> kernel release candidate?
>
> I use NetworkManager and I never see errors like this.
>
> You definitely should use either a newer kernel or the backports
> sources. There is a recent change that fixes a problem in rtl8192ce that
> caused interrupts to be disabled for a long time. That fix is in the
> mainline 3.14-rc5 and in the wireless-testing repo. It is in the process
> of being applied to the various stable kernels, but it is probably not
> there yet.
>
> If you just want to try that patch, it is available at
> https://lkml.org/lkml/2014/2/1/15.
>

Thanks for your reply Larry. I had seen the interrupt latency fix 
(latest release candidate) but since my problem occurs earlier than any 
wifi protocol activity, I abstained from upgrading.

Anyway since you suggested it, I moved to 3.14.0-rc5 and the problem 
occurs exactly as reported earlier (the dmesg indeed reports a different 
module load and init sequence).

 From your suggestions, I should try with tools other than iw and 
iwconfig. I thought the higher level wireless management tools would use 
the same kernel api.

Any other suggestion?

P.S. Yes, the "ip link set up wlan1" command was given. The EBUSY return 
applies equally before and after this command.

Regards,

-- Thierry Moreau

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: rtlwifi (rtl8192ce) consistently reports EBUSY error, but scanning works
  2014-03-05 16:27   ` Thierry Moreau
@ 2014-03-05 16:40     ` Larry Finger
  2014-03-05 19:16       ` Thierry Moreau
  0 siblings, 1 reply; 10+ messages in thread
From: Larry Finger @ 2014-03-05 16:40 UTC (permalink / raw)
  To: Thierry Moreau, linux-wireless

On 03/05/2014 10:27 AM, Thierry Moreau wrote:
> On 03/05/14 07:12, Larry Finger wrote:
>> On 03/05/2014 12:36 AM, Thierry Moreau wrote:
>>> Hi!
>>>
>>> I am using a kind-of "linux from scratch" (i.e. Crux 3.0, 64 bits
>>> Intel, kernel
>>> 3.10.32) and I am stuck with a EBUSY error return from the wireless
>>> driver I
>>> suspect it comes from the driver behavior since it is consistent
>>> either from the
>>> command
>>>
>>> iw dev wlan1 set channel 2
>>>
>>> or the comand
>>>
>>> iwconfig wlan1 set channel 2
>>>
>>> (it occurred also with "iw" with a kernel where the iwconfig support
>>> emulation
>>> is off -- CONFIG_CFG82011_WEXT). The EBUSY error return occurs as
>>> early as
>>> immediately after the initial module install, and consistently
>>> thereafter. The
>>> wireless scanning works (reporting a nearby beacon on channel 1).
>
>>>  [ ... ... ]
>
>>>
>>> Any suggestion about a next step in troubleshooting? Maybe trying the
>>> latest
>>> kernel release candidate?
>>
>> I use NetworkManager and I never see errors like this.
>>
>> You definitely should use either a newer kernel or the backports
>> sources. There is a recent change that fixes a problem in rtl8192ce that
>> caused interrupts to be disabled for a long time. That fix is in the
>> mainline 3.14-rc5 and in the wireless-testing repo. It is in the process
>> of being applied to the various stable kernels, but it is probably not
>> there yet.
>>
>> If you just want to try that patch, it is available at
>> https://lkml.org/lkml/2014/2/1/15.
>>
>
> Thanks for your reply Larry. I had seen the interrupt latency fix (latest
> release candidate) but since my problem occurs earlier than any wifi protocol
> activity, I abstained from upgrading.
>
> Anyway since you suggested it, I moved to 3.14.0-rc5 and the problem occurs
> exactly as reported earlier (the dmesg indeed reports a different module load
> and init sequence).
>
>  From your suggestions, I should try with tools other than iw and iwconfig. I
> thought the higher level wireless management tools would use the same kernel api.
>
> Any other suggestion?
>
> P.S. Yes, the "ip link set up wlan1" command was given. The EBUSY return applies
> equally before and after this command.

Please give me the exact set of commands you use to get this problem. If 
possible, capture the console output. As I am currently running long-term tests 
of the latest version of rtl8192ce using an RTL8188CE (10ec:8176), it will be a 
perfect time to test.

Larry



^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: rtlwifi (rtl8192ce) consistently reports EBUSY error, but scanning works
  2014-03-05 16:40     ` Larry Finger
@ 2014-03-05 19:16       ` Thierry Moreau
  2014-03-06 14:54         ` Peter Wu
  2014-03-06 15:57         ` Larry Finger
  0 siblings, 2 replies; 10+ messages in thread
From: Thierry Moreau @ 2014-03-05 19:16 UTC (permalink / raw)
  To: Larry Finger, linux-wireless

[-- Attachment #1: Type: text/plain, Size: 688 bytes --]

On 03/05/14 16:40, Larry Finger wrote:
>
> Please give me the exact set of commands you use to get this problem. If
> possible, capture the console output. As I am currently running
> long-term tests of the latest version of rtl8192ce using an RTL8188CE
> (10ec:8176), it will be a perfect time to test.
>

Here is the command script, and the console log
(....sh 2>&1 | tee ....log)

Is it possible that the Shuttle system be arranged with a digital output 
enabling/inhibiting the Realtek wifi interface active participation in 
wifi protocol?

I did ask Shuttle tech support, but in any event I don't want to induce 
you to troubleshoot a specific system.

Thanks,

-- Thierry Moreau



[-- Attachment #2: shuttle-x36vl-rtl8192ce-ebusy.log --]
[-- Type: text/plain, Size: 7898 bytes --]

+ uname -a
Linux dodeca1er 3.14.0-rc5 #1 SMP Wed Mar 5 15:38:33 UTC 2014 x86_64 Intel(R) Atom(TM) CPU D2550 @ 1.86GHz GenuineIntel GNU/Linux
+ grep -i wifi -C 4 -n
+ dmesg
711-[    2.581616] gma500 0000:00:02.0: trying to get vblank count for disabled pipe 1
712-[    2.771178] usb 5-2: new low-speed USB device number 2 using uhci_hcd
713-[    2.832203] fbcon: psbdrmfb (fb0) is primary device
714-[    2.832262] rtl8192ce:_rtl92ce_read_chip_version():<0-0> Chip Version ID: B_CUT_88C
715:[    2.844335] rtl8192ce: Using firmware rtlwifi/rtl8192cfwU_B.bin
716-[    2.939453] usb 5-2: New USB device found, idVendor=045e, idProduct=0780
717-[    2.939458] usb 5-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
718-[    2.939462] usb 5-2: Product: Comfort Curve Keyboard 3000
719-[    2.939465] usb 5-2: Manufacturer: Microsoft
--
725-[    3.287718] gma500 0000:00:02.0: fb0: psbdrmfb frame buffer device
726-[    3.287723] gma500 0000:00:02.0: registered panic notifier
727-[    3.287820] [drm] Initialized gma500 1.0.0 2011-06-06 for 0000:00:02.0 on minor 0
728-[    3.396518] ieee80211 phy0: Selected rate control algorithm 'rtl_rc'
729:[    3.397145] rtlwifi: wireless switch is on
730-[    5.834746] Adding 16777212k swap on /dev/sda6.  Priority:42 extents:1 across:16777212k 
731-[    5.859658] Adding 16777212k swap on /dev/sda7.  Priority:52 extents:1 across:16777212k 
732-[    5.883344] Adding 16777212k swap on /dev/sda8.  Priority:62 extents:1 across:16777212k 
733-[    6.872268] gzip (166) used greatest stack depth: 3864 bytes left
+ lsmod
Module                  Size  Used by
rtl8192ce              71392  0 
gma500_gfx            139440  1 
rtl_pci                24810  1 rtl8192ce
rtlwifi                70066  2 rtl_pci,rtl8192ce
rtl8192c_common        53859  1 rtl8192ce
drm_kms_helper         28143  1 gma500_gfx
+ cat
+ iwconfig
eth0      no wireless extensions.

lo        no wireless extensions.

sit0      no wireless extensions.

wlan1     IEEE 802.11bgn  ESSID:off/any  
          Mode:Managed  Access Point: Not-Associated   Tx-Power=0 dBm   
          Retry short limit:7   RTS thr=2347 B   Fragment thr:off
          Encryption key:off
          Power Management:on
          
+ cat
+ iw dev wlan1 info
Interface wlan1
	ifindex 4
	wdev 0x1
	addr 64:5a:04:aa:f8:16
	type managed
	wiphy 0
+ cat
+ iw dev wlan1 set channel 2
command failed: Device or resource busy (-16)
+ cat
+ iw dev wlan1 scan
command failed: Network is down (-100)
+ cat
+ ip link set up wlan1
+ cat
+ iw dev wlan1 scan
BSS d8:6c:e9:29:e5:75(on wlan1)
	TSF: 1358921377410 usec (15d, 17:28:41)
	freq: 2412
	beacon interval: 100 TUs
	capability: ESS Privacy ShortSlotTime APSD (0x0c11)
	signal: -74.00 dBm
	last seen: 929 ms ago
	SSID: BELL417
	Supported rates: 1.0* 2.0* 5.5* 11.0* 9.0 18.0 36.0 54.0 
	DS Parameter set: channel 1
	ERP: Barker_Preamble_Mode
	Extended supported rates: 6.0 12.0 24.0 48.0 
	HT capabilities:
		Capabilities: 0x106e
			HT20/HT40
			SM Power Save disabled
			RX HT20 SGI
			RX HT40 SGI
			No RX STBC
			Max AMSDU length: 3839 bytes
			DSSS/CCK HT40
		Maximum RX AMPDU length 32767 bytes (exponent: 0x002)
		Minimum RX AMPDU time spacing: 4 usec (0x05)
		HT RX MCS rate indexes supported: 0-23, 32
		HT TX MCS rate indexes are undefined
	HT operation:
		 * primary channel: 1
		 * secondary channel offset: above
		 * STA channel width: any
		 * RIFS: 0
		 * HT protection: nonmember
		 * non-GF present: 0
		 * OBSS non-GF present: 0
		 * dual beacon: 0
		 * dual CTS protection: 0
		 * STBC beacon: 0
		 * L-SIG TXOP Prot: 0
		 * PCO active: 0
		 * PCO phase: 0
	Secondary Channel Offset: no secondary (0)
	RSN:	 * Version: 1
		 * Group cipher: CCMP
		 * Pairwise ciphers: CCMP
		 * Authentication suites: PSK
		 * Capabilities: 1-PTKSA-RC 1-GTKSA-RC (0x0000)
	WMM:	 * Parameter version 1
		 * u-APSD
		 * BE: CW 15-1023, AIFSN 3
		 * BK: CW 15-1023, AIFSN 7
		 * VI: CW 7-15, AIFSN 2, TXOP 3008 usec
		 * VO: CW 3-7, AIFSN 2, TXOP 1504 usec
	BSS Load:
		 * station count: 0
		 * channel utilisation: 11/255
		 * available admission capacity: 31250 [*32us]
	Overlapping BSS scan params:
		 * passive dwell: 20 TUs
		 * active dwell: 10 TUs
		 * channel width trigger scan interval: 300 s
		 * scan passive total per channel: 200 TUs
		 * scan active total per channel: 20 TUs
		 * BSS width channel transition delay factor: 5
		 * OBSS Scan Activity Threshold: 0.25 %
	Extended capabilities: HT Information Exchange Supported
	Country: CA	Environment: Indoor/Outdoor
		Channels [1 - 11] @ 16 dBm
	WPS:	 * Version: 1.0
		 * Wi-Fi Protected Setup State: 2 (Configured)
		 * Response Type: 3 (AP)
		 * UUID: 28802880-2880-1880-a880-d86ce929e575
		 * Manufacturer: Ralink Technology, Corp.
		 * Model: Ralink Wireless Access Point
		 * Model Number: RT2860
		 * Serial Number: 12345678
		 * Primary Device Type: 6-0050f204-1
		 * Device name: RalinkAPS
		 * Config methods: Label, PBC
		 * RF Bands: 0x1
+ cat
+ iwlist wlan1 scanning
wlan1     Scan completed :
          Cell 01 - Address: D8:6C:E9:29:E5:75
                    Channel:1
                    Frequency:2.412 GHz (Channel 1)
                    Quality=30/70  Signal level=-80 dBm  
                    Encryption key:on
                    ESSID:"BELL417"
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 9 Mb/s
                              18 Mb/s; 36 Mb/s; 54 Mb/s
                    Bit Rates:6 Mb/s; 12 Mb/s; 24 Mb/s; 48 Mb/s
                    Mode:Master
                    Extra:tsf=0000013c6606a682
                    Extra: Last beacon: 987ms ago
                    IE: Unknown: 000742454C4C343137
                    IE: Unknown: 010882848B961224486C
                    IE: Unknown: 030101
                    IE: Unknown: 2A0104
                    IE: Unknown: 32040C183060
                    IE: Unknown: 2D1A6E1016FFFFFF0001000000000000000000000000030000000000
                    IE: Unknown: 3D1601050100000000000000000000000000000000000000
                    IE: Unknown: 3E0100
                    IE: IEEE 802.11i/WPA2 Version 1
                        Group Cipher : CCMP
                        Pairwise Ciphers (1) : CCMP
                        Authentication Suites (1) : PSK
                    IE: Unknown: DD180050F2020101800003A4000027A4000042435E0062322F00
                    IE: Unknown: 0B0500000B127A
                    IE: Unknown: 4A0E14000A002C01C800140005001900
                    IE: Unknown: 7F0101
                    IE: Unknown: DD07000C4300000000
                    IE: Unknown: 0706434120010B10
                    IE: Unknown: DD9D0050F204104A0001101044000102103B000103104700102880288028801880A880D86CE929E5751021001852616C696E6B20546563686E6F6C6F67792C20436F72702E1023001C52616C696E6B20576972656C6573732041636365737320506F696E74102400065254323836301042000831323334353637381054000800060050F20400011011000952616C696E6B415053100800020084103C000101

+ cat
+ iwconfig wlan1 channel 2
Error for wireless request "Set Frequency" (8B04) :
    SET failed on device wlan1 ; Device or resource busy.
+ cat
+ ip link set down wlan1
+ cat
+ iw dev wlan1 interface add wlan2 type managed
+ cat
+ iwconfig
eth0      no wireless extensions.

lo        no wireless extensions.

sit0      no wireless extensions.

wlan1     IEEE 802.11bgn  ESSID:off/any  
          Mode:Managed  Frequency:2.417 GHz  Access Point: Not-Associated   
          Tx-Power=20 dBm   
          Retry short limit:7   RTS thr=2347 B   Fragment thr:off
          Encryption key:off
          Power Management:off
          
rename5   IEEE 802.11bgn  ESSID:off/any  
          Mode:Managed  Access Point: Not-Associated   Tx-Power=20 dBm   
          Retry short limit:7   RTS thr=2347 B   Fragment thr:off
          Encryption key:off
          Power Management:on
          
+ cat
+ iw dev rename5 set channel 2
command failed: Device or resource busy (-16)
+ cat

[-- Attachment #3: shuttle-x36vl-rtl8192ce-ebusy.sh --]
[-- Type: application/x-sh, Size: 536 bytes --]

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: rtlwifi (rtl8192ce) consistently reports EBUSY error, but scanning works
  2014-03-05 19:16       ` Thierry Moreau
@ 2014-03-06 14:54         ` Peter Wu
  2014-03-06 18:59           ` Thierry Moreau
  2014-03-06 15:57         ` Larry Finger
  1 sibling, 1 reply; 10+ messages in thread
From: Peter Wu @ 2014-03-06 14:54 UTC (permalink / raw)
  To: Thierry Moreau; +Cc: Larry Finger, linux-wireless

[-- Attachment #1: Type: text/plain, Size: 1440 bytes --]

On Wednesday 05 March 2014 19:16:08 Thierry Moreau wrote:
> On 03/05/14 16:40, Larry Finger wrote:
> > Please give me the exact set of commands you use to get this problem. If
> > possible, capture the console output. As I am currently running
> > long-term tests of the latest version of rtl8192ce using an RTL8188CE
> > (10ec:8176), it will be a perfect time to test.
> 
> Here is the command script, and the console log
> (....sh 2>&1 | tee ....log)

Instead of cat, I used single-second sleeps as can be seen in the attached 
script. Our logs are roughly the same (I have replaced the last three bytes of 
the MAC address by XX for privacy). The rtlwifi module is patched[1], hence 
the out-of-tree marking.

What is the problem that you are experiencing? I am able to connect although 
it took half a minute for the first ICMP ping packets to pass (and then there 
is still a lot of packet loss). This pattern is observable on the past 2.5 
weeks that I have been running ping tests (ping every second to the gateway).

> Is it possible that the Shuttle system be arranged with a digital output
> enabling/inhibiting the Realtek wifi interface active participation in
> wifi protocol?

I didn't understand the first part, are you referring to a possible mistake in 
attaching the antennas? When I opened up the case, I saw two antennas that 
were properly secured to the card.

Regards,
Peter

 [1]: http://lkml.org/lkml/2014/2/14/430

[-- Attachment #2: repro-shuttle.sh --]
[-- Type: application/x-shellscript, Size: 451 bytes --]

[-- Attachment #3: repro.txt --]
[-- Type: text/plain, Size: 9857 bytes --]

Script started on Thu 06 Mar 2014 02:43:56 PM CET
+ iface=wlan0
+ uname -a
Linux work 3.14.0-rc2-custom-00267-g9398a10 #4 SMP PREEMPT Wed Feb 12 20:41:43 CET 2014 x86_64 GNU/Linux
+ dmesg
+ grep -i wifi -C 4 -n
1125-[   11.401304] [drm] No driver support for vblank timestamp query.
1126-[   11.514185] rtl8192ce:_rtl92ce_read_chip_version():<0-0> Chip Version ID: B_CUT_88C
1127-[   11.526221] rtl8192ce: rtl8192ce: Power Save off (module option)
1128-[   11.526222] rtl8192ce: rtl8192ce: FW Power Save off (module option)
1129:[   11.526242] rtl8192ce: Using firmware rtlwifi/rtl8192cfwU_B.bin
1130-[   11.604096] systemd[1]: Received SIGCHLD from PID 137 (systemd-vconsol).
1131-[   11.612617] systemd[1]: Got SIGCHLD for process 137 (systemd-vconsol)
1132-[   11.621165] systemd[1]: Child 137 died (code=exited, status=0/SUCCESS)
1133-[   11.629346] systemd[1]: Child 137 belongs to systemd-vconsole-setup.service
--
1148-[   11.839624] cfg80211:   (5170000 KHz - 5250000 KHz @ 80000 KHz), (N/A, 2000 mBm)
1149-[   11.855677] cfg80211:   (5735000 KHz - 5835000 KHz @ 80000 KHz), (N/A, 2000 mBm)
1150-[   11.871911] cfg80211:   (57240000 KHz - 63720000 KHz @ 2160000 KHz), (N/A, 0 mBm)
1151-[   11.888513] ieee80211 phy0: Selected rate control algorithm 'rtl_rc'
1152:[   11.897674] rtlwifi: wireless switch is on
1153-[   11.908296] systemd[1]: sys-subsystem-net-devices-wlan0.device changed dead -> plugged
1154-[   11.911950] input: HDA Intel HDMI/DP,pcm=3 as /devices/pci0000:00/0000:00:1b.0/sound/card0/input10
1155-[   11.913175] input: HDA Intel Front Headphone as /devices/pci0000:00/0000:00:1b.0/sound/card0/input9
1156-[   11.915407] input: HDA Intel Mic as /devices/pci0000:00/0000:00:1b.0/sound/card0/input8
--
1577-[   16.885077] systemd[1]: Got D-Bus request: org.freedesktop.DBus.Local.Disconnected() on /org/freedesktop/DBus/Local
1578-[   16.890932] ------------[ cut here ]------------
1579-[   16.890944] WARNING: CPU: 2 PID: 134 at /home/peter/linux/kernel/locking/mutex.c:516 __mutex_lock_slowpath+0x357/0x370()
1580-[   16.890947] DEBUG_LOCKS_WARN_ON(in_interrupt())
1581:[   16.891013] Modules linked in: xt_tcpudp nf_conntrack_ipv6 nf_conntrack_ipv4 nf_defrag_ipv4 nf_defrag_ipv6 xt_conntrack nf_conntrack iptable_filter ip6table_filter ip_tables ip6_tables x_tables snd_hda_codec_hdmi arc4 snd_hda_codec_idt snd_hda_codec_generic rtl8192ce(O) rtl_pci(O) gma500_gfx rtlwifi(O) mac80211 snd_hda_intel i2c_algo_bit drm_kms_helper snd_hda_codec snd_hwdep drm cfg80211 snd_pcm snd_timer snd evdev r8169 pcspkr iTCO_wdt i2c_i801 i2c_core iTCO_vendor_support video rfkill rtl8192c_common(O) coretemp microcode lpc_ich rtsx_pci_ms mii memstick soundcore fan processor thermal button ext4 crc16 mbcache jbd2 hid_logitech_dj usbhid hid sd_mod rtsx_pci_sdmmc mmc_core ahci libahci libata scsi_mod ehci_pci uhci_hcd ehci_hcd usbcore usb_common rtsx_pci mfd_core
1582-[   16.891018] CPU: 2 PID: 134 Comm: systemd-journal Tainted: G           O 3.14.0-rc2-custom-00267-g9398a10 #4
1583-[   16.891019] Hardware name: Shuttle Inc. XS36V/XS36V, BIOS 1.11 12/18/2012
1584-[   16.891026]  0000000000000009 ffff88012fd03bf0 ffffffff8146cca0 ffff88012fd03c38
1585-[   16.891030]  ffff88012fd03c28 ffffffff8104c45d ffff880037945818 ffff880037945818
+ lsmod
Module                  Size  Used by
xt_tcpudp               3111  1 
nf_conntrack_ipv6       7995  1 
nf_conntrack_ipv4       7754  1 
nf_defrag_ipv4          1403  1 nf_conntrack_ipv4
nf_defrag_ipv6         25934  1 nf_conntrack_ipv6
xt_conntrack            3265  2 
nf_conntrack           66712  3 xt_conntrack,nf_conntrack_ipv4,nf_conntrack_ipv6
iptable_filter          1488  1 
ip6table_filter         1428  1 
ip_tables              16451  1 iptable_filter
ip6_tables             16160  1 ip6table_filter
x_tables               17522  6 ip6table_filter,ip_tables,xt_tcpudp,xt_conntrack,iptable_filter,ip6_tables
snd_hda_codec_hdmi     36172  1 
arc4                    2000  2 
snd_hda_codec_idt      43450  1 
snd_hda_codec_generic    52827  1 snd_hda_codec_idt
rtl8192ce              73667  0 
rtl_pci                24976  1 rtl8192ce
gma500_gfx            174510  1 
rtlwifi                71601  2 rtl_pci,rtl8192ce
mac80211              490444  3 rtl_pci,rtlwifi,rtl8192ce
snd_hda_intel          34841  0 
i2c_algo_bit            5391  1 gma500_gfx
drm_kms_helper         35572  1 gma500_gfx
snd_hda_codec          98879  4 snd_hda_codec_hdmi,snd_hda_codec_idt,snd_hda_codec_generic,snd_hda_intel
snd_hwdep               5852  1 snd_hda_codec
drm                   237941  2 drm_kms_helper,gma500_gfx
cfg80211              430184  2 mac80211,rtlwifi
snd_pcm                80379  3 snd_hda_codec_hdmi,snd_hda_codec,snd_hda_intel
snd_timer              18709  1 snd_pcm
snd                    51167  8 snd_hwdep,snd_timer,snd_hda_codec_hdmi,snd_hda_codec_idt,snd_pcm,snd_hda_codec_generic,snd_hda_codec,snd_hda_intel
evdev                  10981  4 
r8169                  58223  0 
pcspkr                  1995  0 
iTCO_wdt                5407  0 
i2c_i801               11109  0 
i2c_core               23780  5 drm,i2c_i801,drm_kms_helper,i2c_algo_bit,gma500_gfx
iTCO_vendor_support     1929  1 iTCO_wdt
video                  11540  1 gma500_gfx
rfkill                 15683  1 cfg80211
rtl8192c_common        55112  1 rtl8192ce
coretemp                6390  0 
microcode              15090  0 
lpc_ich                13368  0 
rtsx_pci_ms             7418  0 
mii                     4027  1 r8169
memstick                7504  1 rtsx_pci_ms
soundcore                944  1 snd
fan                     2785  0 
processor              24170  0 
thermal                 8556  0 
button                  4477  0 
ext4                  481304  4 
crc16                   1359  1 ext4
mbcache                 6074  1 ext4
jbd2                   82736  1 ext4
hid_logitech_dj        10599  0 
usbhid                 40843  0 
hid                    89807  2 usbhid,hid_logitech_dj
sd_mod                 31817  5 
rtsx_pci_sdmmc         13924  0 
mmc_core               95817  1 rtsx_pci_sdmmc
ahci                   23403  4 
libahci                21484  1 ahci
libata                172031  2 ahci,libahci
scsi_mod              132830  2 libata,sd_mod
ehci_pci                3960  0 
uhci_hcd               33795  0 
ehci_hcd               63800  1 ehci_pci
usbcore               180840  4 uhci_hcd,ehci_hcd,ehci_pci,usbhid
usb_common              1648  1 usbcore
rtsx_pci               32831  2 rtsx_pci_ms,rtsx_pci_sdmmc
mfd_core                3249  2 lpc_ich,rtsx_pci
+ sleep 1
+ iwconfig
eth0      no wireless extensions.

lo        no wireless extensions.

wlan0     IEEE 802.11bgn  ESSID:off/any  
          Mode:Managed  Access Point: Not-Associated   Tx-Power=0 dBm   
          Retry short limit:7   RTS thr=2347 B   Fragment thr:off
          Encryption key:off
          Power Management:on
          
+ sleep 1
+ iw dev wlan0 info
Interface wlan0
	ifindex 3
	wdev 0x1
	addr e0:91:53:XX:XX:XX
	type managed
	wiphy 0
+ sleep 1
+ iw dev wlan0 set channel 2
command failed: Device or resource busy (-16)
+ sleep 1
+ iw dev wlan0 scan
command failed: Network is down (-100)
+ sleep 1
+ ip link set up wlan0
+ sleep 1
+ iw dev wlan0 scan
BSS 48:f9:25:00:01:13(on wlan0)
	TSF: 10820542146 usec (0d, 03:00:20)
	freq: 2472
	beacon interval: 100 TUs
	capability: ESS ShortPreamble ShortSlotTime (0x0421)
	signal: -54.00 dBm
	last seen: 26 ms ago
	Information elements from Probe Response frame:
	SSID: Hermes_Mobile_Hotspot
	Supported rates: 1.0* 2.0 5.5 11.0 
	DS Parameter set: channel 13
+ sleep 1
+ iwlist wlan0 scanning
wlan0     Scan completed :
          Cell 01 - Address: 48:F9:25:00:01:13
                    Channel:13
                    Frequency:2.472 GHz (Channel 13)
                    Quality=56/70  Signal level=-54 dBm  
                    Encryption key:off
                    ESSID:"Hermes_Mobile_Hotspot"
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s
                    Mode:Master
                    Extra:tsf=0000000284f45ec2
                    Extra: Last beacon: 1943ms ago
                    IE: Unknown: 00154865726D65735F4D6F62696C655F486F7473706F74
                    IE: Unknown: 010482040B16
                    IE: Unknown: 03010D
                    IE: Unknown: DD2A000C42000000011E001000000066160500004C563132333437000000000000000000000000000502A809

+ sleep 1
+ iwconfig wlan0 channel 2
Error for wireless request "Set Frequency" (8B04) :
    SET failed on device wlan0 ; Device or resource busy.
+ sleep 1
+ ip link set down wlan0
+ sleep 1
+ iw dev wlan0 interface add wlan2 type managed
+ sleep 1
+ iwconfig
wlan2     IEEE 802.11bgn  ESSID:off/any  
          Mode:Managed  Access Point: Not-Associated   Tx-Power=20 dBm   
          Retry short limit:7   RTS thr=2347 B   Fragment thr:off
          Encryption key:off
          Power Management:on
          
eth0      no wireless extensions.

lo        no wireless extensions.

wlan0     IEEE 802.11bgn  ESSID:off/any  
          Mode:Managed  Frequency:2.417 GHz  Access Point: Not-Associated   
          Tx-Power=20 dBm   
          Retry short limit:7   RTS thr=2347 B   Fragment thr:off
          Encryption key:off
          Power Management:off
          
+ sleep 1
+ iw dev wlan2 set channel 2
command failed: Device or resource busy (-16)
+ sleep 1

real	0m15.794s
user	0m0.137s
sys	0m0.417s

Script done on Thu 06 Mar 2014 02:44:12 PM CET

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: rtlwifi (rtl8192ce) consistently reports EBUSY error, but scanning works
  2014-03-06 14:54         ` Peter Wu
@ 2014-03-06 18:59           ` Thierry Moreau
  0 siblings, 0 replies; 10+ messages in thread
From: Thierry Moreau @ 2014-03-06 18:59 UTC (permalink / raw)
  To: Peter Wu; +Cc: Larry Finger, linux-wireless

On 03/06/14 14:54, Peter Wu wrote:
> On Wednesday 05 March 2014 19:16:08 Thierry Moreau wrote:
>> On 03/05/14 16:40, Larry Finger wrote:
>>> Please give me the exact set of commands you use to get this problem. If
>>> possible, capture the console output. As I am currently running
>>> long-term tests of the latest version of rtl8192ce using an RTL8188CE
>>> (10ec:8176), it will be a perfect time to test.
>>
>> Here is the command script, and the console log
>> (....sh 2>&1 | tee ....log)
>
> Instead of cat, I used single-second sleeps as can be seen in the attached
> script. Our logs are roughly the same (I have replaced the last three bytes of
> the MAC address by XX for privacy). The rtlwifi module is patched[1], hence
> the out-of-tree marking.
>
> What is the problem that you are experiencing?
>

Indeed a good question! Likely there is no problem. Likely a
misunderstanding from my part of the wifi logic.

I was going step by step in my integration and I (wrongly?) assumed that 
the command to set a channel in the wifi configuration was a requirement 
for my next step: scanning done on an older wifi system detected signals 
from multiple channels but the newer system scanning saw only channel 1, 
hence I assumed that the newer scanning scheme needed channel changes by 
the user space logic.

Now a number of clues (including your log below -- thanks) point towards 
the inconsequential-ness of the EBUSY result in the specific command I 
was using as a milestone.

Other clues: a) suggestion by Larry to try other tools, and b) an EBUSY 
return code in net/wireless/chan.c .

Somewhere else I might learn how scanning on multiple channels can work, 
but I no longer care for my deployment priorities.

> I am able to connect although
> it took half a minute for the first ICMP ping packets to pass (and then there
> is still a lot of packet loss). This pattern is observable on the past 2.5
> weeks that I have been running ping tests (ping every second to the gateway).
>
>> Is it possible that the Shuttle system be arranged with a digital output
>> enabling/inhibiting the Realtek wifi interface active participation in
>> wifi protocol?
>
> I didn't understand the first part, are you referring to a possible mistake in
> attaching the antennas? When I opened up the case, I saw two antennas that
> were properly secured to the card.
>

Please ignore this other hypothesis.

Thanks a lot to Larry and Peter. If you don't ear from me, please assume 
that I successfully installed hostapd and I am an happy rtlwifi user 
with the kernel 3.14.

-- Thierry Moreau

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: rtlwifi (rtl8192ce) consistently reports EBUSY error, but scanning works
  2014-03-05 19:16       ` Thierry Moreau
  2014-03-06 14:54         ` Peter Wu
@ 2014-03-06 15:57         ` Larry Finger
  2014-03-06 17:40           ` Dan Williams
  1 sibling, 1 reply; 10+ messages in thread
From: Larry Finger @ 2014-03-06 15:57 UTC (permalink / raw)
  To: Thierry Moreau, linux-wireless

On 03/05/2014 01:16 PM, Thierry Moreau wrote:
> On 03/05/14 16:40, Larry Finger wrote:
>>
>> Please give me the exact set of commands you use to get this problem. If
>> possible, capture the console output. As I am currently running
>> long-term tests of the latest version of rtl8192ce using an RTL8188CE
>> (10ec:8176), it will be a perfect time to test.
>>
>
> Here is the command script, and the console log
> (....sh 2>&1 | tee ....log)
>
> Is it possible that the Shuttle system be arranged with a digital output
> enabling/inhibiting the Realtek wifi interface active participation in wifi
> protocol?
>
> I did ask Shuttle tech support, but in any event I don't want to induce you to
> troubleshoot a specific system.

The problem is not specific to the Shuttle - I can reproduce it on my HP laptop. 
Furthermore, it affects other mac80211-based drivers. The EBUSY return comes out 
of mac80211/cfg80211/nl80211 code.

I have no idea why that particular set of commands fails to be able to set the 
channel. Both NetworkManager and the openSUSE ifup sequence work OK. Your system 
can set channels using the scan mechanism.

If you want to track it down, you will need to put printk statements at every 
place that the net/wireless code sets EBUSY to see which one triggers. Perhaps 
that will expose any bug there, or in your script.

Larry

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: rtlwifi (rtl8192ce) consistently reports EBUSY error, but scanning works
  2014-03-06 15:57         ` Larry Finger
@ 2014-03-06 17:40           ` Dan Williams
  0 siblings, 0 replies; 10+ messages in thread
From: Dan Williams @ 2014-03-06 17:40 UTC (permalink / raw)
  To: Larry Finger; +Cc: Thierry Moreau, linux-wireless

On Thu, 2014-03-06 at 09:57 -0600, Larry Finger wrote:
> On 03/05/2014 01:16 PM, Thierry Moreau wrote:
> > On 03/05/14 16:40, Larry Finger wrote:
> >>
> >> Please give me the exact set of commands you use to get this problem. If
> >> possible, capture the console output. As I am currently running
> >> long-term tests of the latest version of rtl8192ce using an RTL8188CE
> >> (10ec:8176), it will be a perfect time to test.
> >>
> >
> > Here is the command script, and the console log
> > (....sh 2>&1 | tee ....log)
> >
> > Is it possible that the Shuttle system be arranged with a digital output
> > enabling/inhibiting the Realtek wifi interface active participation in wifi
> > protocol?
> >
> > I did ask Shuttle tech support, but in any event I don't want to induce you to
> > troubleshoot a specific system.
> 
> The problem is not specific to the Shuttle - I can reproduce it on my HP laptop. 
> Furthermore, it affects other mac80211-based drivers. The EBUSY return comes out 
> of mac80211/cfg80211/nl80211 code.

I deleted the earlier bits of this thread after skimming it, but IIRC
we're talking about scanning here right?  If there's already a scan
in-progress, then the stack can often return EBUSY.

For example, from both cfg80211_wext_siwscan() and
nl80211_trigger_scan(), used by 'iwlist' and 'iw' respectively:

	if (rdev->scan_req) {
		err = -EBUSY;
		goto out;
	}

Scans do not get canceled just because another random scan request comes
in.  Whatever userspace there is needs to wait for a scan completion
event and then request it's new scan.  There are also stack internal
scans that happen from time to time that may cause a user-requested scan
to return EBUSY.

(NM hands this all off to wpa_supplicant, which itself handles the EBUSY
by waiting a bit and then requesting another scan.)

Dan


^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: rtlwifi (rtl8192ce) consistently reports EBUSY error, but scanning works
  2014-03-05  6:36 rtlwifi (rtl8192ce) consistently reports EBUSY error, but scanning works Thierry Moreau
  2014-03-05  7:12 ` Larry Finger
@ 2014-03-05 10:51 ` Peter Wu
  1 sibling, 0 replies; 10+ messages in thread
From: Peter Wu @ 2014-03-05 10:51 UTC (permalink / raw)
  To: Thierry Moreau; +Cc: linux-wireless

On Wednesday 05 March 2014 06:36:50 Thierry Moreau wrote:
> I am using a kind-of "linux from scratch" (i.e. Crux 3.0, 64 bits
> Intel, kernel 3.10.32) and I am stuck with a EBUSY error return from
> the wireless driver I suspect it comes from the driver behavior since
> it is consistent either from the command
> 
> iw dev wlan1 set channel 2
> 
> or the comand
> 
> iwconfig wlan1 set channel 2
> 
> (it occurred also with "iw" with a kernel where the iwconfig support
> emulation is off -- CONFIG_CFG82011_WEXT). The EBUSY error return
> occurs as early as immediately after the initial module install, and
> consistently thereafter. The wireless scanning works (reporting a
> nearby beacon on channel 1).

It was not entirely clear for me, but have you enabled the interface
before changing the channel? I.e.

    ip link set wlan0 up
    iw dev wlan0 set channel 2

I suggest to try 3.13 or even 3.14(-rcish). Earlier kernels (3.10 being
the worst) had an issue[1] that impacted wireless stability.

> The system is a Shuttle XS36VL box
> (http://us.shuttle.com/barebone/Models/XS36VL.html). It does not have
> a physical wireless switch (a dmesg line above reports the switch
> position as "on").

The same box is operating in my neighbourhood (networking was not
required for its purpose). Good luck with getting multi-head working.
This box is running 3.14-rc2-something now with patches to get monitor
mode to function properly.

Kind regards,
Peter

 [1]: https://bugzilla.kernel.org/show_bug.cgi?id=60713

^ permalink raw reply	[flat|nested] 10+ messages in thread

end of thread, other threads:[~2014-03-06 18:59 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2014-03-05  6:36 rtlwifi (rtl8192ce) consistently reports EBUSY error, but scanning works Thierry Moreau
2014-03-05  7:12 ` Larry Finger
2014-03-05 16:27   ` Thierry Moreau
2014-03-05 16:40     ` Larry Finger
2014-03-05 19:16       ` Thierry Moreau
2014-03-06 14:54         ` Peter Wu
2014-03-06 18:59           ` Thierry Moreau
2014-03-06 15:57         ` Larry Finger
2014-03-06 17:40           ` Dan Williams
2014-03-05 10:51 ` Peter Wu

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