RE: [BUG] wifi: rtw88: Hard system freeze on RTL8821CE when power_save is enabled (LPS/ASPM conflict)

[Ping-Ke Shih]

LB F <goainwo@xxxxxxxxx> wrote:
> Ping-Ke Shih <pkshih@xxxxxxxxxxx> wrote:
> > Not sure what hardware get wrong. Let's validate rate when reading
> > from hardware. Since 1M rate can only 20MHz, I set it together.
> > Please help to test below. I suppose you can see "weird rate=xxx",
> > but "WARNING: net/mac80211/rx.c:5491" disappears.
> 
> Hi Ping-Ke,
> 
> I can confirm your patch works as expected. Here are the full results.
> 
> --- Test environment ---
> 
> Kernel:  6.19.7-1-cachyos
> Patch:   your rate validation patch applied to rtw_rx_query_rx_desc(),
>          on top of the v2 DMI quirk (ASPM + LPS Deep disabled)
> 
> --- Captured log (relevant excerpt) ---
> 
>   [  43.046] input: Soundcore Q10i (AVRCP)   <-- BT headset connected
>   [ 111.551] rtw_8821ce 0000:13:00.0: unused phy status page (13)
>   [ 111.635] weird rate=101
>   [ 111.635] rtw_8821ce 0000:13:00.0: unused phy status page (7)
>   [ 111.741] weird rate=102
>   [ 115.045] weird rate=98
>   [ 118.371] weird rate=104
> 
> --- Analysis ---
> 
> 1. Timing: the anomalous events began approximately 68 seconds after
>    the Bluetooth A2DP headset (Soundcore Q10i) established its
>    connection. No anomalies were observed before BT connected.
> 
> 2. Multiple invalid rate values were captured, not just 0x65:
> 
>      weird rate=101  (0x65)
>      weird rate=102  (0x66)
>      weird rate=98   (0x62)
>      weird rate=104  (0x68)
> 
>    All four values exceed DESC_RATE_MAX (0x53 = 83 decimal). This
>    suggests the hardware occasionally reports a range of out-of-bounds
>    rate values during BT/Wi-Fi coexistence, not a single fixed value.
> 
> 3. The "unused phy status page" messages (pages 13 and 7) appeared
>    immediately before and alongside the "weird rate" events. As noted
>    in my previous message, only pages 0 and 1 are expected. This
>    further suggests the firmware leaks internal coexistence state
>    into the RX ring during BT antenna arbitration.
> 
> 4. Most importantly: the WARNING: net/mac80211/rx.c:5491 did NOT
>    appear anywhere in the log. Your rate clamping patch successfully
>    intercepts the out-of-bounds values before they propagate to
>    mac80211, preventing the invalid VHT NSS=0 warning entirely.
> 
> --- Conclusion ---
> 
> Your patch achieves the intended result. The "weird rate" printk
> confirms the hardware is the source of the invalid values (occurring
> during BT coexistence), and the mac80211 WARNING is suppressed.
> 
> Please let me know if you need any additional data or further testing.

I'll send formal patch (Cc you) for the invalid VHT NSS=0, but not to
handle "unused phy status page". Please give me Tested-by tag on the
patch after I send it.

Ping-Ke