Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.19 029/287] serial: mvebu-uart: uart2 error bits clearing | Date | Tue, 23 Aug 2022 10:23:18 +0200 |
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From: Narendra Hadke <nhadke@marvell.com>
commit a7209541239e5dd44d981289e5f9059222d40fd1 upstream.
For mvebu uart2, error bits are not cleared on buffer read. This causes interrupt loop and system hang.
Cc: stable@vger.kernel.org Reviewed-by: Yi Guo <yi.guo@cavium.com> Reviewed-by: Nadav Haklai <nadavh@marvell.com> Signed-off-by: Narendra Hadke <nhadke@marvell.com> Signed-off-by: Pali Rohár <pali@kernel.org> Link: https://lore.kernel.org/r/20220726091221.12358-1-pali@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/tty/serial/mvebu-uart.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
--- a/drivers/tty/serial/mvebu-uart.c +++ b/drivers/tty/serial/mvebu-uart.c @@ -237,6 +237,7 @@ static void mvebu_uart_rx_chars(struct u struct tty_port *tport = &port->state->port; unsigned char ch = 0; char flag = 0; + int ret; do { if (status & STAT_RX_RDY(port)) { @@ -249,6 +250,16 @@ static void mvebu_uart_rx_chars(struct u port->icount.parity++; } + /* + * For UART2, error bits are not cleared on buffer read. + * This causes interrupt loop and system hang. + */ + if (IS_EXTENDED(port) && (status & STAT_BRK_ERR)) { + ret = readl(port->membase + UART_STAT); + ret |= STAT_BRK_ERR; + writel(ret, port->membase + UART_STAT); + } + if (status & STAT_BRK_DET) { port->icount.brk++; status &= ~(STAT_FRM_ERR | STAT_PAR_ERR);
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