Re: [PATCH rtw-next v9 0/4] wifi: rtw88: sdio: Fix unhandled RX request interrupt storm

[Luka Gejak]

Hi Ping-Ke,

November 8, 2026 at 4:06 AM, "Ping-Ke Shih" <pkshih@xxxxxxxxxxx> wrote:

> 
> Luka Gejak <luka.gejak@xxxxxxxxx> wrote:
> 
> > 
> > November 7, 2026 at 4:53 AM, "Alastair D'Silva" <alastair@xxxxxxxxxxx> wrote:
> >  
> > 
> >  On 3081-based SDIO chips (observed on RTL8821CS; RTL8822BS and RTL8822CS
> >  are inferred to be affected as they share the 3081 architecture), clearing
> >  REG_SDIO_HISR_RX_REQUEST requires both a software W1C acknowledge and an
> >  empty RX FIFO. Masking this bit out before writing back to HISR prevents
> >  the software acknowledge from happening, leaving the bit asserted even
> >  after the FIFO is drained and trapping the CPU core in an infinite
> >  interrupt storm that locks up the system upon receiving network traffic.
> > 
> >  This series fixes the interrupt storm on 3081 chips and addresses
> >  related SDIO lifecycle, locking, and error handling issues:
> > 
> >  - Patch 1 returns error codes from rtw_sdio_rxfifo_recv() on allocation,
> >  oversized packet, or read failures so the caller stops immediately
> >  instead of burning through the loop budget.
> >  - Patch 2 tracks operational state via rtwsdio->running protected by an
> >  irq_lock mutex (using a mutex as SDIO bus operations sleep), serializes
> >  start/stop state transitions under sdio_claim_host() and irq_lock,
> >  cancels the TX worker synchronously on stop, drains rtwsdio->tx_queue[]
> >  with locked skb_dequeue() and ieee80211_free_txskb() in rtw_sdio_stop()
> >  and again in rtw_sdio_start(), and resets rtwsdio->tx_queue_stopped[]
> >  while waking stopped AC queues under tx_queue[].lock in rtw_sdio_start().
> >  - Patch 3 fixes the interrupt storm by splitting
> >  rtw_sdio_handle_interrupt() into 8051 and 3081 paths. On 3081,
> >  interrupts are masked via HIMR, acknowledged via W1C writeback,
> >  serviced, and re-enabled under irq_lock if still running.
> >  - Patch 4 refactors rtw_sdio_rx_isr() into separate 8051 and 3081 variants
> >  to clarify the differences in register width and HISR handling without
> >  any logic changes.
> > 
> >  
> >  Thanks for addressing those comments, v9 looks good to me,
> >  
> >  Reviewed-by: Luka Gejak <luka.gejak@xxxxxxxxx>
> > 
> I don't know why I can't see v10 in patchwork [1].

I suppose you mean v9.

> Please take Luka's Reviewed-by for each patch, and send v10.
> 
> [1] https://patchwork.kernel.org/project/linux-wireless/list/?series=&submitter=Alastair&state=*&q=&archive=&delegate=
>

It might be the same issue lore is experiencing. Nothing newer than
November 6th is appearing, maybe it's related?

Best regards,
Luka Gejak