From a2a2113ab0813917f298a60d42c87eb7e8cf977e Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Tue, 22 Nov 2022 16:35:29 +0100 Subject: [PATCH] 4.9-stable patches added patches: serial-8250-flush-dma-rx-on-rlsi.patch --- .../serial-8250-flush-dma-rx-on-rlsi.patch | 41 +++++++++++++++++++ queue-4.9/series | 1 + 2 files changed, 42 insertions(+) create mode 100644 queue-4.9/serial-8250-flush-dma-rx-on-rlsi.patch diff --git a/queue-4.9/serial-8250-flush-dma-rx-on-rlsi.patch b/queue-4.9/serial-8250-flush-dma-rx-on-rlsi.patch new file mode 100644 index 00000000000..18892508822 --- /dev/null +++ b/queue-4.9/serial-8250-flush-dma-rx-on-rlsi.patch @@ -0,0 +1,41 @@ +From 1980860e0c8299316cddaf0992dd9e1258ec9d88 Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= +Date: Tue, 8 Nov 2022 14:19:52 +0200 +Subject: serial: 8250: Flush DMA Rx on RLSI +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +From: Ilpo Järvinen + +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: +Signed-off-by: Ilpo Järvinen +Reviewed-by: Andy Shevchenko +Link: https://lore.kernel.org/r/20221108121952.5497-5-ilpo.jarvinen@linux.intel.com +Signed-off-by: Greg Kroah-Hartman +--- + drivers/tty/serial/8250/8250_port.c | 3 +-- + 1 file changed, 1 insertion(+), 2 deletions(-) + +--- a/drivers/tty/serial/8250/8250_port.c ++++ b/drivers/tty/serial/8250/8250_port.c +@@ -1802,10 +1802,9 @@ static bool handle_rx_dma(struct uart_82 + if (!up->dma->rx_running) + break; + /* fall-through */ ++ case UART_IIR_RLSI: + case UART_IIR_RX_TIMEOUT: + serial8250_rx_dma_flush(up); +- /* fall-through */ +- case UART_IIR_RLSI: + return true; + } + return up->dma->rx_dma(up); diff --git a/queue-4.9/series b/queue-4.9/series index 1b1fc867361..0a20bba85c7 100644 --- a/queue-4.9/series +++ b/queue-4.9/series @@ -63,3 +63,4 @@ serial-8250_lpss-configure-dma-also-w-o-dma-filter.patch mmc-core-properly-select-voltage-range-without-power-cycle.patch misc-vmw_vmci-fix-an-infoleak-in-vmci_host_do_receive_datagram.patch nilfs2-fix-use-after-free-bug-of-ns_writer-on-remount.patch +serial-8250-flush-dma-rx-on-rlsi.patch -- 2.47.3