Re: r8188eu driver in 5.15 only shows wifi networks on channel 11

Pavel Skripkin
2021-11-05T09:20:32Z

On 11/5/21 07:34, Zameer Manji wrote:

[ +CC other guys related to r8188eu ]

> Hello,
>
> I am reporting a regression in 5.15 in the r8188eu driver. Apologies
> if this is not the right mailing list to report the issue, I am not
> sure if reporting issues in staging drivers is appropriate for
> linux-wireless list.
>
> I have a TP Link TL-WN725N device [0]. With 5.14 it is able to connect
> to my wifi network and operate as expected. With 5.15 it is not able
> to, the root cause appears that the wifi network no longer shows up in
> `iwlist wlan0 scanning`. Here is the entry that shows up in 5.14 but
> not in 5.15:
> ```
> Cell 01 - Address: A0:40:A0:85:B9:FA
> ESSID:"WIFI.-SLOW"
> Protocol:IEEE 802.11bgn
> Mode:Master
> Frequency:2.447 GHz (Channel 8)
> Encryption key:on
> Bit Rates:144 Mb/s
> Extra:rsn_ie=30140100000fac040100000fac040100000fac020c00
> IE: IEEE 802.11i/WPA2 Version 1
> Group Cipher : CCMP
> Pairwise Ciphers (1) : CCMP
> Authentication Suites (1) : PSK
> IE: Unknown:
> DD7D0050F204104A0001101044000102103B000103104700105AAA8B8AF2347DC2798F056F8BC933551021000D4E4554474541522C20496E632E10230006523730303050102400065237303030501042000233321054000800060050F204000110110006523730303050100800022008103C0001031049000600372A000120
> Quality=100/100 Signal level=100/100
> ```
>
> The only networks that show up in `iwlist wlan0 scanning` in 5.15 have
> `Frequency:2.462 GHz (Channel 11)` networks on other channels do not
> show up.
>

Can you try to bisect to offending commit? I've just tested v5.15 kernel
on my test vm and I see following output:

```

root@syzkaller:~# iwlist wlx28ee5214eeb6 scanning | grep "Channel"
Frequency:2.412 GHz (Channel 1)
Frequency:2.412 GHz (Channel 1)
Frequency:2.417 GHz (Channel 2)
Frequency:2.417 GHz (Channel 2)
Frequency:2.427 GHz (Channel 4)
Frequency:2.422 GHz (Channel 3)
Frequency:2.417 GHz (Channel 2)
Frequency:2.437 GHz (Channel 6)
Frequency:2.427 GHz (Channel 4)
Frequency:2.442 GHz (Channel 7)
Frequency:2.462 GHz (Channel 11)
Frequency:2.462 GHz (Channel 11)
Frequency:2.457 GHz (Channel 10)
Frequency:2.467 GHz (Channel 12)
Frequency:2.472 GHz (Channel 13)
Frequency:2.412 GHz (Channel 1)
Frequency:2.412 GHz (Channel 1)
Frequency:2.442 GHz (Channel 7)
Frequency:2.472 GHz (Channel 13)
root@syzkaller:~# uname -r
5.15.0
root@syzkaller:~#

```

And I am able to connect to my Wi-Fi.

I see only weird slab-out-of-bounce bug with debug=9, but, I think, it's
unrelated to your problem. Bisection would be really great :)

With regards,
Pavel Skripkin

> I don't have any kernel parameters set, and I am using the same
> firmware for both kernels. If it matters, the kernels were taken from
> Ubuntu's Mainline PPA [1].
>
> Full output from lsusb for this device.
>
> ```
> Bus 003 Device 002: ID 0bda:8179 Realtek Semiconductor Corp.
> RTL8188EUS 802.11n Wireless Network Adapter
> Device Descriptor:
> bLength 18
> bDescriptorType 1
> bcdUSB 2.00
> bDeviceClass 0
> bDeviceSubClass 0
> bDeviceProtocol 0
> bMaxPacketSize0 64
> idVendor 0x0bda Realtek Semiconductor Corp.
> idProduct 0x8179 RTL8188EUS 802.11n Wireless Network Adapter
> bcdDevice 0.00
> iManufacturer 1 Realtek
> iProduct 2 802.11n NIC
> iSerial 3 00E04C0001
> bNumConfigurations 1
> Configuration Descriptor:
> bLength 9
> bDescriptorType 2
> wTotalLength 0x0027
> bNumInterfaces 1
> bConfigurationValue 1
> iConfiguration 0
> bmAttributes 0xa0
> (Bus Powered)
> Remote Wakeup
> MaxPower 500mA
> Interface Descriptor:
> bLength 9
> bDescriptorType 4
> bInterfaceNumber 0
> bAlternateSetting 0
> bNumEndpoints 3
> bInterfaceClass 255 Vendor Specific Class
> bInterfaceSubClass 255 Vendor Specific Subclass
> bInterfaceProtocol 255 Vendor Specific Protocol
> iInterface 0
> Endpoint Descriptor:
> bLength 7
> bDescriptorType 5
> bEndpointAddress 0x81 EP 1 IN
> bmAttributes 2
> Transfer Type Bulk
> Synch Type None
> Usage Type Data
> wMaxPacketSize 0x0200 1x 512 bytes
> bInterval 0
> Endpoint Descriptor:
> bLength 7
> bDescriptorType 5
> bEndpointAddress 0x02 EP 2 OUT
> bmAttributes 2
> Transfer Type Bulk
> Synch Type None
> Usage Type Data
> wMaxPacketSize 0x0200 1x 512 bytes
> bInterval 0
> Endpoint Descriptor:
> bLength 7
> bDescriptorType 5
> bEndpointAddress 0x03 EP 3 OUT
> bmAttributes 2
> Transfer Type Bulk
> Synch Type None
> Usage Type Data
> wMaxPacketSize 0x0200 1x 512 bytes
> bInterval 0
> ```
>
> Related dmesg output in 5.15
> ```
> [ 13.542110] r8188eu: module is from the staging directory, the
> quality is unknown, you have been warned.
> [ 13.570753] Chip Version Info:
> CHIP_8188E_Normal_Chip_TSMC_D_CUT_1T1R_RomVer(0)
> [ 13.623399] EEPROM ID = 0x8129
> [ 13.646796] usbcore: registered new interface driver r8188eu
> [ 14.416673] R8188EU: Firmware Version 11, SubVersion 1, Signature 0x88e1
> [ 15.484020] R8188EU: INFO indicate disassoc
> ```
>
> Please let me know if any other information is needed in root causing
> this bug, or if this bug should
> be directed elsewhere.
>