From: Martin Blumenstingl martin.blumenstingl@googlemail.com
[ Upstream commit e967229ead0e6c5047a1cfd5a0db58ceb930800b ]
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@realtek.com Signed-off-by: Martin Blumenstingl martin.blumenstingl@googlemail.com Signed-off-by: Kalle Valo kvalo@kernel.org Link: https://lore.kernel.org/r/20230522202425.1827005-2-martin.blumenstingl@googl... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/wireless/realtek/rtw88/sdio.c | 24 ++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-)
diff --git a/drivers/net/wireless/realtek/rtw88/sdio.c b/drivers/net/wireless/realtek/rtw88/sdio.c index 06fce7c3addaa..2c1fb2dabd40a 100644 --- a/drivers/net/wireless/realtek/rtw88/sdio.c +++ b/drivers/net/wireless/realtek/rtw88/sdio.c @@ -998,9 +998,9 @@ static void rtw_sdio_rxfifo_recv(struct rtw_dev *rtwdev, u32 rx_len)
static void rtw_sdio_rx_isr(struct rtw_dev *rtwdev) { - u32 rx_len, total_rx_bytes = 0; + u32 rx_len, hisr, total_rx_bytes = 0;
- while (total_rx_bytes < SZ_64K) { + do { if (rtw_chip_wcpu_11n(rtwdev)) rx_len = rtw_read16(rtwdev, REG_SDIO_RX0_REQ_LEN); else @@ -1012,7 +1012,25 @@ static void rtw_sdio_rx_isr(struct rtw_dev *rtwdev) rtw_sdio_rxfifo_recv(rtwdev, rx_len);
total_rx_bytes += rx_len; - } + + if (rtw_chip_wcpu_11n(rtwdev)) { + /* Stop if no more RX requests are pending, even if + * rx_len could be greater than zero in the next + * iteration. This is needed because the RX buffer may + * already contain data while either HW or FW are not + * done filling that buffer yet. Still reading the + * buffer can result in packets where + * rtw_rx_pkt_stat.pkt_len is zero or points beyond the + * end of the buffer. + */ + hisr = rtw_read32(rtwdev, REG_SDIO_HISR); + } else { + /* RTW_WCPU_11AC chips have improved hardware or + * firmware and can use rx_len unconditionally. + */ + hisr = REG_SDIO_HISR_RX_REQUEST; + } + } while (total_rx_bytes < SZ_64K && hisr & REG_SDIO_HISR_RX_REQUEST); }
static void rtw_sdio_handle_interrupt(struct sdio_func *sdio_func)