tty: serial: msm: Move request_irq to the end of startup
Move the request_irq() call to the end of the msm_startup(),
so that we don't handle interrupts while msm_startup() is
running. This avoids potential races while initialization
is in progress. For example, consider below scenario
where rx handler reads the intermediate value of dma->chan,
set in msm_request_rx_dma(), and tries to do dma mapping,
which results in data abort.
uart_port_startup()
msm_startup()
request_irq()
...
msm_request_rx_dma()
...
dma->chan = dma_request_slave_channel_reason(dev, "rx");
<UART RX IRQ>
msm_uart_irq()
msm_handle_rx_dm()
msm_start_rx_dma()
dma->desc = dma_map_single()
<data abort>
Signed-off-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Reviewd-by: Andy Gross <andy.gross@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 file changed