Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx> wrote: > rtw_sdio_rx_isr() is responsible for receiving data from the wifi chip > and is called from the SDIO interrupt handler when the interrupt status > register (HISR) has the RX_REQUEST bit set. After the first batch of > data has been processed by the driver the wifi chip may have more data > ready to be read, which is managed by a loop in rtw_sdio_rx_isr(). > > It turns out that there are cases where the RX buffer length (from the > REG_SDIO_RX0_REQ_LEN register) does not match the data we receive. The > following two cases were observed with a RTL8723DS card: > - RX length is smaller than the total packet length including overhead > and actual data bytes (whose length is part of the buffer we read from > the wifi chip and is stored in rtw_rx_pkt_stat.pkt_len). This can > result in errors like: > skbuff: skb_over_panic: text:ffff8000011924ac len:3341 put:3341 > (one case observed was: RX buffer length = 1536 bytes but > rtw_rx_pkt_stat.pkt_len = 1546 bytes, this is not valid as it means > we need to read beyond the end of the buffer) > - RX length looks valid but rtw_rx_pkt_stat.pkt_len is zero > > Check if the RX_REQUEST is set in the HISR register for each iteration > inside rtw_sdio_rx_isr(). This mimics what the RTL8723DS vendor driver > does and makes the driver only read more data if the RX_REQUEST bit is > set (which seems to be a way for the card's hardware or firmware to > tell the host that data is ready to be processed). > > For RTW_WCPU_11AC chips this check is not needed. The RTL8822BS vendor > driver for example states that this check is unnecessary (but still uses > it) and the RTL8822CS drops this check entirely. > > Reviewed-by: Ping-Ke Shih <pkshih@xxxxxxxxxxx> > Signed-off-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx> 4 patches applied to wireless-next.git, thanks. e967229ead0e wifi: rtw88: sdio: Check the HISR RX_REQUEST bit in rtw_sdio_rx_isr() 9be20a822327 wifi: rtw88: rtw8723d: Implement RTL8723DS (SDIO) efuse parsing 09fcdbd28404 mmc: sdio: Add/rename SDIO ID of the RTL8723DS SDIO wifi cards a3b125ceb45e wifi: rtw88: Add support for the SDIO based RTL8723DS chipset -- https://patchwork.kernel.org/project/linux-wireless/patch/20230522202425.1827005-2-martin.blumenstingl@xxxxxxxxxxxxxx/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
