diff options
| author | Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> | 2022-11-08 15:19:52 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-11-25 19:45:52 +0300 |
| commit | 8679087e93574742d7cceb001d7a1bd558585395 (patch) | |
| tree | e71308cf80ef088cf64d5b0e3b04cbd25cb9f6f0 | |
| parent | a5eaad87bfca23b851a68f1f233ddd6f0bb25192 (diff) | |
| download | linux-8679087e93574742d7cceb001d7a1bd558585395.tar.xz | |
serial: 8250: Flush DMA Rx on RLSI
commit 1980860e0c8299316cddaf0992dd9e1258ec9d88 upstream.
Returning true from handle_rx_dma() without flushing DMA first creates
a data ordering hazard. If DMA Rx has handled any character at the
point when RLSI occurs, the non-DMA path handles any pending characters
jumping them ahead of those characters that are pending under DMA.
Fixes: 75df022b5f89 ("serial: 8250_dma: Fix RX handling")
Cc: <stable@vger.kernel.org>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20221108121952.5497-5-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/serial/8250/8250_port.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 7a15bb14194c..1f231fcda657 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -1873,10 +1873,9 @@ static bool handle_rx_dma(struct uart_8250_port *up, unsigned int iir) if (!up->dma->rx_running) break; fallthrough; + case UART_IIR_RLSI: case UART_IIR_RX_TIMEOUT: serial8250_rx_dma_flush(up); - fallthrough; - case UART_IIR_RLSI: return true; } return up->dma->rx_dma(up); |