Hi Ping-Ke, Kalle, Martin, sorry for my late reply. Yes, this patch fixes my original problems and I have usable WiFi now. There are still some remaining problems like connection dropouts every minute or so, but it's unrelated and a topic of further investigation. Tested-by: Lukas F. Hartmann <lukas@xxxxxxxxx> Best Lukas -- Lukas F. Hartmann, CEO MNT Research GmbH https://mntre.com Kalle Valo <kvalo@xxxxxxxxxx> writes: > Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx> wrote: > >> Lukas reports skb_over_panic errors on his Banana Pi BPI-CM4 which comes >> with an Amlogic A311D (G12B) SoC and a RTL8822CS SDIO wifi/Bluetooth >> combo card. The error he observed is identical to what has been fixed >> in commit e967229ead0e ("wifi: rtw88: sdio: Check the HISR RX_REQUEST >> bit in rtw_sdio_rx_isr()") but that commit didn't fix Lukas' problem. >> >> Lukas found that disabling or limiting RX aggregation works around the >> problem for some time (but does not fully fix it). In the following >> discussion a few key topics have been discussed which have an impact on >> this problem: >> - The Amlogic A311D (G12B) SoC has a hardware bug in the SDIO controller >> which prevents DMA transfers. Instead all transfers need to go through >> the controller SRAM which limits transfers to 1536 bytes >> - rtw88 chips don't split incoming (RX) packets, so if a big packet is >> received this is forwarded to the host in it's original form >> - rtw88 chips can do RX aggregation, meaning more multiple incoming >> packets can be pulled by the host from the card with one MMC/SDIO >> transfer. This Depends on settings in the REG_RXDMA_AGG_PG_TH >> register (BIT_RXDMA_AGG_PG_TH limits the number of packets that will >> be aggregated, BIT_DMA_AGG_TO_V1 configures a timeout for aggregation >> and BIT_EN_PRE_CALC makes the chip honor the limits more effectively) >> >> Use multiple consecutive reads in rtw_sdio_read_port() and limit the >> number of bytes which are copied by the host from the card in one >> MMC/SDIO transfer. This allows receiving a buffer that's larger than >> the hosts max_req_size (number of bytes which can be transferred in >> one MMC/SDIO transfer). As a result of this the skb_over_panic error >> is gone as the rtw88 driver is now able to receive more than 1536 bytes >> from the card (either because the incoming packet is larger than that >> or because multiple packets have been aggregated). >> >> In case of an receive errors (-EILSEQ has been observed by Lukas) we >> need to drain the remaining data from the card's buffer, otherwise the >> card will return corrupt data for the next rtw_sdio_read_port() call. >> >> Fixes: 65371a3f14e7 ("wifi: rtw88: sdio: Add HCI implementation for SDIO based chipsets") >> Reported-by: Lukas F. Hartmann <lukas@xxxxxxxxx> >> Closes: https://lore.kernel.org/linux-wireless/CAFBinCBaXtebixKbjkWKW_WXc5k=NdGNaGUjVE8NCPNxOhsb2g@xxxxxxxxxxxxxx/ >> Suggested-by: Ping-Ke Shih <pkshih@xxxxxxxxxxx> >> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx> >> Reviewed-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> >> Acked-by: Ping-Ke Shih <pkshih@xxxxxxxxxxx> > > Did this fix Lukas' problem? I couldn't see any answer to Ping's > question. > > Patch set to Deferred. > > -- > https://patchwork.kernel.org/project/linux-wireless/patch/20231120115726.1569323-1-martin.blumenstingl@xxxxxxxxxxxxxx/ > > https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches >
