From: Jorge Ramirez-Ortiz jorge.ramirez-ortiz@linaro.org
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: 68252424a7c7 ("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
--- drivers/tty/serial/msm_serial.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
--- a/drivers/tty/serial/msm_serial.c +++ b/drivers/tty/serial/msm_serial.c @@ -860,6 +860,7 @@ static void msm_handle_tx(struct uart_po struct circ_buf *xmit = &msm_port->uart.state->xmit; struct msm_dma *dma = &msm_port->tx_dma; unsigned int pio_count, dma_count, dma_min; + char buf[4] = { 0 }; void __iomem *tf; int err = 0;
@@ -869,10 +870,12 @@ static void msm_handle_tx(struct uart_po else tf = port->membase + UART_TF;
+ buf[0] = port->x_char; + if (msm_port->is_uartdm) msm_reset_dm_count(port, 1);
- iowrite8_rep(tf, &port->x_char, 1); + iowrite32_rep(tf, buf, 1); port->icount.tx++; port->x_char = 0; return;