Re: [PATCH ath-next] wifi: ath12k: change MAC buffer ring size to 4096

[Baochen Qiang <baochen.qiang@oss.qualcomm.com>]

On 10/22/2026 5:20 PM, Shawn Guo wrote:
> On Thu, Oct 22, 2026 at 10:30:45AM +0800, Baochen Qiang wrote:
>>
>>
>> On 10/20/2026 4:53 PM, Shawn Guo wrote:
>>> + linux-arm-msm
>>>
>>> On Tue, Jun 09, 2026 at 08:13:58PM -0700, Yingying Tang wrote:
>>>> For WCN7850, MAC buffer ring size is updated to 2048 in
>>>> 955df16f2a4c3 ("wifi: ath12k: change MAC buffer ring size to 2048")
>>>> to increase peak throughput.
>>>>
>>>> But during the RX process, a phenomenon can still be observed where
>>>> the throughput drops by about 30% from its peak value and then recovers,
>>>> and this behavior repeats during RX.
>>>>
>>>> After increasing MAC buffer ring size to 4096, the data rate drop has
>>>> gone.
>>>>
>>>> Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.1.c5-00302-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.115823.3
>>>>
>>>> Signed-off-by: Yingying Tang <yingying.tang@oss.qualcomm.com>
>>>
>>> FYI, in case someone else runs into this: with this change (merged in
>>> v7.3), WiFi on my Lenovo Yoga Slim 7x (X1E80100, WCN7850 hw2.0) stopped
>>> working with the older firmware that Debian trixie still ships
>>> (firmware-atheros 20250410-2):
>>>
>>>   WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3
>>>
>>> Probe and firmware download succeed, but every WMI command times out
>>> once the interface is brought up:
>>>
>>>   ath12k_wifi7_pci 0004:01:00.0: wmi command 16387 timeout
>>>   ath12k_wifi7_pci 0004:01:00.0: failed to send WMI_PDEV_SET_PARAM cmd
>>>   ath12k_wifi7_pci 0004:01:00.0: failed to enable PMF QOS: -11
>>>   ath12k_wifi7_pci 0004:01:00.0: fail to start mac operations in pdev idx 0 ret -11
>>>
>>> Bisecting ath12k between v7.2 and v7.3 lands on this commit, and
>>> reverting it on v7.3 brings WiFi back with the old firmware.
>>>
>>> Unmodified v7.3 works fine after updating to the current linux-firmware
>>> image:
>>>
>>>   WLAN.HMT.1.1.c7-00108-QCAHMTSWPL_V1.0_V2.0_SILICONZ_UPSTREAM-3
>>>
>>> On Debian trixie that one is available from trixie-backports
>>> (firmware-atheros 20260916-1~bpo13+1).
>>>
>>> So nothing needs fixing on the driver side. I'm just leaving this here
>>> so that anyone who sees "wmi command ... timeout" on WCN7850 after a
>>> kernel upgrade knows to update the firmware first.
>>
>> Hi Shawn, thanks for reporting this. I just had a quick test
>> WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3 with the latest ath tree
>> (ath-202610191908), everything looks good, simple connection and ping pass, I don't see
>> any ath12k warning.
>>
>> The firmware images I am using comes from the first commit adding WCN7850 firmware:
>>
>> 	fb04a7f4b750 ("ath12k: add new driver and firmware for WCN7850")
>>
>> and the md5 values are:
>>
>> linux-firmware/ath12k/WCN7850/hw2.0$ md5sum ./*
>> d3750b67b1013fe82358d0538fb131b0  ./amss.bin
>> c79c410d585360000c0490f16fda43e2  ./board-2.bin
>> 73056f1d2aff886ce9bff313f455e963  ./m3.bin
>> d0ee61498bf1a205147cdbcf645391e7  ./Notice.txt
>>
>> can you share the md5 values of your images?
> 
> Hi Baochen,
> 
> Here are md5 values of the old firmware shipped by trixie firmware-atheros
> 20250410-2.
> 
> $ md5sum /lib/firmware/ath12k/WCN7850/hw2.0/*
> d3750b67b1013fe82358d0538fb131b0  /lib/firmware/ath12k/WCN7850/hw2.0/amss.bin
> 5dacdfbe6c3c25d9e0605be8a9f1f6e4  /lib/firmware/ath12k/WCN7850/hw2.0/board-2.bin

this is different from mine, can you try mine?

> 73056f1d2aff886ce9bff313f455e963  /lib/firmware/ath12k/WCN7850/hw2.0/m3.bin
> 
>> and have you ever tried the upstream mainline
>> kernel or the latest ath.git tree?
> 
> I'm not sure what you mean by upstream mainline kernel, but v7.3 should

I mean Linus's tree

> be the mainline kernel released a few days ago.
> 
> On the other hand, I just tested ath.git tree at tag ath-202610191908,
> and it worked with the old firmware. So it seems there are some gaps
> between v7.3 and ath kernel.

can you share the exact tag of v7.3 kernel? is it just below tag?

commit c03c1a14507dfaf8b856c2608f9ac216021fc222 (tag: v7.3)
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Sun Oct 18 13:14:58 2026 -1000

    Linux 7.3

diff --git a/Makefile b/Makefile
index 0dc1a9f4e63e..c61ea07ee505 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@
 VERSION = 7
 PATCHLEVEL = 3
 SUBLEVEL = 0
-EXTRAVERSION = -rc7
+EXTRAVERSION =
 NAME = Baby Opossum Posse

 # *DOCUMENTATION*


> 
> Shawn