From: Douglas Anderson Date: Fri, 13 Mar 2020 20:46:51 +0000 (-0700) Subject: tty: serial: qcom_geni_serial: No need to stop tx/rx on UART shutdown X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=e83766334f96b3396a71c7baa3b0b53dfd5190cd;p=openwrt%2Fstaging%2Fblogic.git tty: serial: qcom_geni_serial: No need to stop tx/rx on UART shutdown On a board using qcom_geni_serial I found that I could no longer interact with kdb if I got a crash after the "agetty" running on the same serial port was killed. This meant that various classes of crashes that happened at reboot time were undebuggable. Reading through the code, I couldn't figure out why qcom_geni_serial felt the need to run so much code at port shutdown time. All we need to do is disable the interrupt. After I make this change then a hardcoded kgdb_breakpoint in some late shutdown code now allows me to interact with the debugger. I also could freely close / re-open the port without problems. Fixes: c4f528795d1a ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP") Signed-off-by: Douglas Anderson Link: https://lore.kernel.org/r/20200313134635.1.Icf54c533065306b02b880c46dfd401d8db34e213@changeid Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index 1a61c970f7d6..a77f05b7a649 100644 --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -825,17 +825,11 @@ static void get_tx_fifo_size(struct qcom_geni_serial_port *port) static void qcom_geni_serial_shutdown(struct uart_port *uport) { - unsigned long flags; - /* Stop the console before stopping the current tx */ if (uart_console(uport)) console_stop(uport->cons); disable_irq(uport->irq); - spin_lock_irqsave(&uport->lock, flags); - qcom_geni_serial_stop_tx(uport); - qcom_geni_serial_stop_rx(uport); - spin_unlock_irqrestore(&uport->lock, flags); } static int qcom_geni_serial_port_setup(struct uart_port *uport)