[PATCH v2] mac80211: reject/clear user rate mask if not usable

[Wen Gong]

On 2020-11-13 15:38, Johannes Berg wrote:
> On Fri, 2020-11-13 at 10:08 +0800, Wen Gong wrote:
>> 
>> > Which was the intent of this change, wasn't it?
> 
> Indeed. Permitting this leads to warnings later.
> 
>> We need to set the tx rate to fixed at a single rate, e.g.,
>> 54M/48M/36M... for a test case.
>> I do not want a clear error message, I want to the 54M rate pass/set
>> success to lower wlan driver.
>> Then lower wlan driver can handle it.
> 
> No, that will not happen. You should configure your test AP to actually
> support 54M.
Yes, the AP support 54M, but it is not basic rate, so 
ieee80211_set_bitrate_mask will reject 54M
because fail for check (mask->control[band].legacy & basic_rates).

suppor rates of my AP:
Tag: Supported Rates 6(B), 9, 12(B), 18, 24(B), 36, 48, 54, [Mbit/sec]
     Tag Number: Supported Rates (1)
     Tag length: 8
     Supported Rates: 6(B) (0x8c)
     Supported Rates: 9 (0x12)
     Supported Rates: 12(B) (0x98)
     Supported Rates: 18 (0x24)
     Supported Rates: 24(B) (0xb0)
     Supported Rates: 36 (0x48)
     Supported Rates: 48 (0x60)
     Supported Rates: 54 (0x6c)

> 
> johannes