ath9k broken [was: Linux 5.7.3]

[Jiri Slaby]

On 25. 06. 20, 0:05, Gabriel C wrote:
> Am Mi., 17. Juni 2020 um 18:13 Uhr schrieb Greg Kroah-Hartman
> <gregkh@xxxxxxxxxxxxxxxxxxx>:
>>
>> I'm announcing the release of the 5.7.3 kernel.
>>
> 
> Hello Greg,
> 
>> Qiujun Huang (5):
>>       ath9k: Fix use-after-free Read in htc_connect_service
>>       ath9k: Fix use-after-free Read in ath9k_wmi_ctrl_rx
>>       ath9k: Fix use-after-free Write in ath9k_htc_rx_msg
>>       ath9x: Fix stack-out-of-bounds Write in ath9k_hif_usb_rx_cb
>>       ath9k: Fix general protection fault in ath9k_hif_usb_rx_cb
>>
> 
> We got a report on IRC about 5.7.3+ breaking a USB ath9k Wifi Dongle,
> while working fine on <5.7.3.
> 
> I don't have myself such HW, and the reported doesn't have any experience
> in bisecting the kernel, so we build kernels, each with one of the
> above commits reverted,
> to find the bad commit.
> 
> The winner is:
> 
> commit 6602f080cb28745259e2fab1a4cf55eeb5894f93
> Author: Qiujun Huang <hqjagain@xxxxxxxxx>
> Date:   Sat Apr 4 12:18:38 2020 +0800
> 
>     ath9k: Fix general protection fault in ath9k_hif_usb_rx_cb
> 
>     commit 2bbcaaee1fcbd83272e29f31e2bb7e70d8c49e05 upstream.
> ...
> 
> Reverting this one fixed his problem.

Obvious question: is 5.8-rc1 (containing the commit) broken too?

I fail to see how the commit could cause an issue like this. Is this
really reproducibly broken with the commit and irreproducible without
it? As it looks like a USB/wiring problem:
usb 1-2: USB disconnect, device number 2
ath: phy0: Reading Magic # failed
ath: phy0: Unable to initialize hardware; initialization status: -5
...
usb 1-2: device descriptor read/64, error -110
usb 1-2: device descriptor read/64, error -71

Ccing ath9k maintainers too.

> I don't have so much info about the HW, besides a dmesg showing the
> phy breaking.
> I also added the reporter to CC too.
> 
> https://gist.github.com/AngryPenguinPL/1e545f0da3c2339e443b9e5044fcccea
> 
> If you need more info, please let me know and I'll try my best to get
> it as fast as possible for you.

thanks,
-- 
js