Commit a071517b authored May 20, 2019 by Jorge Ramirez-Ortiz Committed by Greg Kroah-Hartman Jun 09, 2019

tty: serial: msm_serial: Fix XON/XOFF



commit 61c0e37950b88bad590056286c1d766b1f167f4e upstream.

When the tty layer requests the uart to throttle, the current code
executing in msm_serial will trigger "Bad mode in Error Handler" and
generate an invalid stack frame in pstore before rebooting (that is if
pstore is indeed configured: otherwise the user shall just notice a
reboot with no further information dumped to the console).

This patch replaces the PIO byte accessor with the word accessor
already used in PIO mode.

Fixes: 68252424 ("tty: serial: msm: Support big-endian CPUs")
Cc: stable@vger.kernel.org
Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent bb032904

drivers/tty/serial/msm_serial.c

+4 −1

Original line number	Original line	Diff line number	Diff line
	@@ -860,6 +860,7 @@ static void msm_handle_tx(struct uart_port *port)
	struct circ_buf *xmit = &msm_port->uart.state->xmit;		struct circ_buf *xmit = &msm_port->uart.state->xmit;
	struct msm_dma *dma = &msm_port->tx_dma;		struct msm_dma *dma = &msm_port->tx_dma;
	unsigned int pio_count, dma_count, dma_min;		unsigned int pio_count, dma_count, dma_min;
			char buf[4] = { 0 };
	void __iomem *tf;		void __iomem *tf;
	int err = 0;		int err = 0;

	@@ -869,10 +870,12 @@ static void msm_handle_tx(struct uart_port *port)
	else		else
	tf = port->membase + UART_TF;		tf = port->membase + UART_TF;

			buf[0] = port->x_char;

	if (msm_port->is_uartdm)		if (msm_port->is_uartdm)
	msm_reset_dm_count(port, 1);		msm_reset_dm_count(port, 1);

	iowrite8_rep(tf, &port->x_char, 1);		iowrite32_rep(tf, buf, 1);
	port->icount.tx++;		port->icount.tx++;
	port->x_char = 0;		port->x_char = 0;
	return;		return;