Re: [PATCH ath-next] wifi: ath12k: limit WMI_SCAN_CHAN_LIST_CMDID argument size

From: Vasanthakumar Thiagarajan
Date: Thu Mar 13 2025 - 07:15:23 EST




On 3/13/2025 3:40 PM, Mantas wrote:
On 2025-03-13 11:45, Vasanthakumar Thiagarajan wrote:


On 3/10/2025 6:58 PM, Mantas Pucka wrote:
When using BDF with both 5GHz and 6GHz bands enabled on QCN9274, interface
fails to start. It happens because FW fails to process
WMI_SCAN_CHAN_LIST_CMDID with argument size >2048, resulting in a command
timeout. The current code allows splitting channel list across multiple WMI
commands but uses WMI max_msg_len (4096) as chunk size, which is still too

Did you have any private changes to increase the message_len from current
2048 ot 4096 bytes? As mentioned in a reply for your other patch, multi-band
in qcn9274 requires additional changes in driver, only scan mode is supported
even with those changes.

No private changes, using unmodified FW from:

https://git.codelinaro.org/clo/ath-firmware/ath12k-firmware/-/tree/main/QCN9274/hw2.0/1.4.1/WLAN.WBE.1.4.1-00199-QCAHKSWPL_SILICONZ-1

max_msg_len comes from FW initialization message:

ath12k_htc_connect_service max_msg_len=0 flags_len=0x0 assigned_eid=0
boot htc service 'Control' ul pipe 0 dl pipe 1 eid 0 ready
ath12k_htc_connect_service max_msg_len=2040 flags_len=0x7f80100 assigned_eid=1
boot htc service 'HTT Data' ul pipe 4 dl pipe 1 eid 1 ready
ath12k_htc_connect_service max_msg_len=4088 flags_len=0xff80200 assigned_eid=2
boot htc service 'WMI' ul pipe 3 dl pipe 2 eid 2 ready


Ah, I see. It looks like firmware does not strictly honor the host configuration
in some cases.


Is support for multi-band AP/STA limited by FW? AFAIK it works with proprietary driver.


There are no validations done with multi-band AP/STA mode configurations.
So we can not really claim the support.

Vasanth