[REGRESSION] [BISECTED] MT7925 wireless speed drops to zero since kernel 6.14.3 - wifi: mt76: mt7925: integrate *mlo_sta_cmd and *sta_cmd

[Mingyen Hsieh (謝明諺)]

On Thu, 2025-08-14 at 14:55 +0300, Tal Inbar wrote:
> 
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
> 
> 
> Hi Mingyen,
> 
> I've collected some of my Routers' configuration information which
> I'll share with you in a private email message.
> 
> Tal
> 
> On Mon, Aug 11, 2025 at 12:08 PM Tal Inbar <inbartdev at gmail.com>
> wrote:
> > 
> > Hi Mingyen,
> > 
> > I'll see what I can gather and I'll let you know.
> > 
> > Tal
> > 
> > On Mon, Aug 11, 2025 at 4:47 AM Mingyen Hsieh (謝明諺)
> > <Mingyen.Hsieh at mediatek.com> wrote:
> > > 
> > > On Fri, 2025-08-08 at 17:37 +0300, Tal Inbar wrote:
> > > > 
> > > > External email : Please do not click links or open attachments
> > > > until
> > > > you have verified the sender or the content.
> > > > 
> > > > 
> > > > typo, laptop model is:
> > > > Lenovo IdeaPad Slim 5 16AKP10
> > > > 
> > > > On Fri, Aug 8, 2025 at 4:14 PM Tal Inbar <inbartdev at gmail.com>
> > > > wrote:
> > > > > 
> > > > > Hi,
> > > > > 
> > > > > Since kernel v6.14.3, when using wireless to connect to my
> > > > > home
> > > > > router
> > > > > on my laptop, my wireless connection slows down to unusable
> > > > > speeds.
> > > > > 
> > > > > 
> > > > > More specifically, since kernel 6.14.3, when connecting to
> > > > > the
> > > > > wireless networks of my OpenWRT Router on my Lenovo IdeaPad
> > > > > Slim 15
> > > > > 16AKP10 laptop,
> > > > > either a 2.4ghz or a 5ghz network, the connection speed drops
> > > > > down
> > > > > to
> > > > > 0.1-0.2 Mbps download and 0 Mbps upload when measured using
> > > > > speedtest-cli.
> > > > > My laptop uses an mt7925 chip according to the loaded driver
> > > > > and
> > > > > firmware.
> > > > > 
> > > > > 
> > > > > Detailed Description:
> > > > > 
> > > > > As mentioned above, my wireless connection becomes unusable
> > > > > when
> > > > > using
> > > > > linux 6.14.3 and above, dropping speeds to almost 0 Mbps,
> > > > > even when standing next to my router. Further, pinging
> > > > > archlinux.org
> > > > > results in "Temporary failure in name resolution".
> > > > > Any other wireless device in my house can successfully
> > > > > connect to
> > > > > my
> > > > > router and properly use the internet with good speeds, eg.
> > > > > iphones,
> > > > > ipads, raspberry pi and a windows laptop.
> > > > > When using my Lenovo laptop on a kernel 6.14.3 or higher to
> > > > > connect
> > > > > to
> > > > > other access points, such as my iPhone's hotspot and some
> > > > > TPLink
> > > > > and
> > > > > Zyxel routers - the connection speed is good, and there are
> > > > > no
> > > > > issues,
> > > > > which makes me believe there's something going on with my
> > > > > OpenWRT
> > > > > configuration in conjunction with a commit introduced on
> > > > > kernel
> > > > > 6.14.3
> > > > > for the mt7925e module as detailed below.
> > > > > 
> > > > > I have followed a related issue previously reported on the
> > > > > mailing
> > > > > list regarding a problem with the same wifi chip on kernel
> > > > > 6.14.3,
> > > > > but
> > > > > the merged fix doesn't seem to fix my problem:
> > > > > https://lore.kernel.org/linux-mediatek/EmWnO5b-acRH1TXbGnkx41eJw654vmCR-8_xMBaPMwexCnfkvKCdlU5u19CGbaapJ3KRu-l3B-tSUhf8CCQwL0odjo6Cd5YG5lvNeB-vfdg=@pm.me/
> > > > > 
> > > > > I've tested stable builds of 6.15 as well up to 6.15.9 in the
> > > > > last
> > > > > month, which also do not fix the problem.
> > > > > I've also built and bisected v6.14 on june using guides on
> > > > > the Arch
> > > > > Linux wiki, for the following bad commit, same as the
> > > > > previously
> > > > > mentioned reported issue:
> > > > > 
> > > > > [80007d3f92fd018d0a052a706400e976b36e3c87] wifi: mt76:
> > > > > mt7925:
> > > > > integrate *mlo_sta_cmd and *sta_cmd
> > > > > 
> > > > > Testing further this week, I cloned mainline after 6.16 was
> > > > > released,
> > > > > built and tested it, and the issue still persists.
> > > > > I reverted the following commits on mainline and retested, to
> > > > > successfully see good wireless speeds:
> > > > > 
> > > > > [0aa8496adda570c2005410a30df963a16643a3dc] wifi: mt76:
> > > > > mt7925: fix
> > > > > missing hdr_trans_tlv command for broadcast wtbl
> > > > > [cb1353ef34735ec1e5d9efa1fe966f05ff1dc1e1] wifi: mt76:
> > > > > mt7925:
> > > > > integrate *mlo_sta_cmd and *sta_cmd
> > > > > 
> > > > > Then, reverting *only*
> > > > > 0aa8496adda570c2005410a30df963a16643a3dc
> > > > > causes
> > > > > the issue to reproduce, which confirms the issue is caused by
> > > > > commit
> > > > > cb1353ef34735ec1e5d9efa1fe966f05ff1dc1e1 on mainline.
> > > > > 
> > > > > I've attached the following files to a bugzilla ticket:
> > > > > 
> > > > > - lspci -nnk output:
> > > > > https://urldefense.com/v3/__https://bugzilla.kernel.org/attachment.cgi?id=308466__;!!CTRNKA9wMg0ARbw!gTAaJeIN6s3eF_Kp6U3iwfv0wCCO_BVcRkNVpJYnwR8qeqIIh134mEJ5dxdeNqzuWSPF2ocLAt43LxaBTIY-7w$
> > > > > 
> > > > > - dmesg output:
> > > > > https://urldefense.com/v3/__https://bugzilla.kernel.org/attachment.cgi?id=308465__;!!CTRNKA9wMg0ARbw!gTAaJeIN6s3eF_Kp6U3iwfv0wCCO_BVcRkNVpJYnwR8qeqIIh134mEJ5dxdeNqzuWSPF2ocLAt43LxY1pkjZCA$
> > > > > 
> > > > > - .config for the built mainline kernel:
> > > > > https://urldefense.com/v3/__https://bugzilla.kernel.org/attachment.cgi?id=308467__;!!CTRNKA9wMg0ARbw!gTAaJeIN6s3eF_Kp6U3iwfv0wCCO_BVcRkNVpJYnwR8qeqIIh134mEJ5dxdeNqzuWSPF2ocLAt43LxYcu-Db2g$
> > > > > 
> > > > > 
> > > > > More information:
> > > > > 
> > > > > OS Distribution: Arch Linux
> > > > > 
> > > > > Linux build information from /proc/version:
> > > > > Linux version 6.16.0linux-mainline-11853-g21be711c0235
> > > > > (tal at arch-debug) (gcc (GCC) 15.1.1 20250729, GNU ld (GNU
> > > > > Binutils)
> > > > > 2.45.0) #3 SMP PREEMPT_DYNAMIC
> > > > > 
> > > > > OpenWRT Version on my Router: 24.10.2
> > > > > 
> > > > > Laptop Hardware:
> > > > > - Lenovo IdeaPad Slim 15 16AKP10 laptop (x86_64 Ryzen AI 350
> > > > > CPU)
> > > > > - Network device as reported by lscpi: 14c3:7925
> > > > > - Network modules and driver in use: mt7925e
> > > > > - mediatek chip firmware as of dmesg:
> > > > >   HW/SW Version: 0x8a108a10, Build Time: 20250526152947a
> > > > >   WM Firmware Version: ____000000, Build Time: 20250526153043
> > > > > 
> > > > > 
> > > > > Referencing regzbot:
> > > > > 
> > > > > #regzbot introduced: 80007d3f92fd018d0a052a706400e976b36e3c87
> > > > > 
> > > > > 
> > > > > Please let me know if any other information is needed, or if
> > > > > there
> > > > > is
> > > > > anything else that I can test on my end.
> > > > > 
> > > > > Thanks,
> > > > > Tal Inbar
> > > 
> > > Hi,
> > > 
> > > Can you capture a sniffer log? There should be some configuration
> > > differences that we can identify from the packet frames during
> > > the
> > > connection process. So please provide the sniffer logs when
> > > connecting
> > > to your OpenWRT, TPLink, and Zyxel.
> > > 
> > > Or you can check for any configuration differences between
> > > OpenWRT and
> > > the other routers, which might also help with debugging.
> > > 
> > > Thanks~
> > > 
> > > Yen.
> > > 
> > > 
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Hi,

As we discussion on the private mail, this issue has been fixed at this
patch:
https://patchwork.kernel.org/project/linux-wireless/patch/20250818030201.997940-1-mingyen.hsieh@mediatek.com/

Thanks.