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Subject: Re: every other wireless scan shows bogus (too low) signal strengths
To:     Johannes Berg <johannes@sipsolutions.net>,
        linux-wireless@vger.kernel.org
References: <b48efa92-9eee-d491-1149-a7cee08300c0@airpost.net>
 <80556c56e69405d7c8f8bc3d57e2ba697074c660.camel@sipsolutions.net>
From:   Bruno Dantas <dantas@airpost.net>
Message-ID: <9093c08e-302d-578c-3e16-619d238b4022@airpost.net>
Date:   Thu, 1 Dec 2022 15:06:00 -0500
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Hi, Johannes. Thank you for your help.

To exclude a bad network card, I replaced my laptop's card with a different one (with the same Intel AC 7265 chipset). The replacement card fared no better. Therefore, I put the original card back and ensured that the two antenna wires are securely connected. There is no doubt now that the wires are secure, but the problem persists.

Unfortunately I cannot seem to make  trace-cmd  work:

bruno@x230:~$ sudo trace-cmd record -e iwlwifi
trace-cmd: No such file or directory
  No events enabled with iwlwifi
bruno@x230:~$ sudo trace-cmd record -e iwlwifi -e mac80211 -e cfg80211 -e iwlwifi_msg
trace-cmd: No such file or directory
  No events enabled with iwlwifi

Perhaps the  iwlwifi  kernel module was not configured to allow this operation? I found this line in my kernel's configuration:

$ cat /boot/config-5.10.0-9-amd64
---snip---
# CONFIG_IWLWIFI_DEVICE_TRACING is not set
---snip---

Oh, well. This is proving to be a tough nut to crack. My workaround for the time being is to discard every other wifi hotspot scan. Since my minimalistic laptop only performs wifi scans in one shell script, this is easy to achieve:

iw dev wlan0 scan flush >/dev/null 
iw dev wlan0 scan flush >/tmp/scan_results.txt

It's a kludge alright, but it will tide me over until I figure out what the real problem is (if ever).

-Bruno