| Message ID | 20200421141234.v2.8.If2deff9679a62c1ce1b8f2558a8635dc837adf8c@changeid (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | kgdb: Support late serial drivers; enable early debug w/ boot consoles | expand |
On Tue, Apr 21, 2020 at 02:14:46PM -0700, Douglas Anderson wrote: > Implement the read() function in the early console driver. With > recent kgdb patches this allows you to use kgdb to debug fairly early > into the system boot. > > We only bother implementing this if polling is enabled since kgdb > can't be enabled without that. > > Signed-off-by: Douglas Anderson <dianders@chromium.org> > --- > > Changes in v2: None > > drivers/tty/serial/qcom_geni_serial.c | 32 +++++++++++++++++++++++++++ > 1 file changed, 32 insertions(+) > > diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c > index 6119090ce045..4563d152b39e 100644 > --- a/drivers/tty/serial/qcom_geni_serial.c > +++ b/drivers/tty/serial/qcom_geni_serial.c > @@ -1090,6 +1090,36 @@ static void qcom_geni_serial_earlycon_write(struct console *con, > __qcom_geni_serial_console_write(&dev->port, s, n); > } > > +#ifdef CONFIG_CONSOLE_POLL > +static int qcom_geni_serial_earlycon_read(struct console *con, > + char *s, unsigned int n) > +{ > + struct earlycon_device *dev = con->data; > + struct uart_port *uport = &dev->port; > + int num_read = 0; > + int ch; > + > + while (num_read < n) { > + ch = qcom_geni_serial_get_char(uport); > + if (ch == NO_POLL_CHAR) > + break; > + s[num_read++] = ch; > + } > + > + return num_read; > +} > + > +static void __init qcom_geni_serial_enable_early_read(struct geni_se *se, > + struct console *con) > +{ > + geni_se_setup_s_cmd(se, UART_START_READ, 0); > + con->read = qcom_geni_serial_earlycon_read; > +} > +#else > +static inline void qcom_geni_serial_enable_early_read(struct geni_se *se, > + struct console *con) { ; } This is pure nitpicking but since I was passing... why the ; ? Daniel.
diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index 6119090ce045..4563d152b39e 100644 --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -1090,6 +1090,36 @@ static void qcom_geni_serial_earlycon_write(struct console *con, __qcom_geni_serial_console_write(&dev->port, s, n); } +#ifdef CONFIG_CONSOLE_POLL +static int qcom_geni_serial_earlycon_read(struct console *con, + char *s, unsigned int n) +{ + struct earlycon_device *dev = con->data; + struct uart_port *uport = &dev->port; + int num_read = 0; + int ch; + + while (num_read < n) { + ch = qcom_geni_serial_get_char(uport); + if (ch == NO_POLL_CHAR) + break; + s[num_read++] = ch; + } + + return num_read; +} + +static void __init qcom_geni_serial_enable_early_read(struct geni_se *se, + struct console *con) +{ + geni_se_setup_s_cmd(se, UART_START_READ, 0); + con->read = qcom_geni_serial_earlycon_read; +} +#else +static inline void qcom_geni_serial_enable_early_read(struct geni_se *se, + struct console *con) { ; } +#endif + static int __init qcom_geni_serial_earlycon_setup(struct earlycon_device *dev, const char *opt) { @@ -1136,6 +1166,8 @@ static int __init qcom_geni_serial_earlycon_setup(struct earlycon_device *dev, dev->con->write = qcom_geni_serial_earlycon_write; dev->con->setup = NULL; + qcom_geni_serial_enable_early_read(&se, dev->con); + return 0; } OF_EARLYCON_DECLARE(qcom_geni, "qcom,geni-debug-uart",
Implement the read() function in the early console driver. With recent kgdb patches this allows you to use kgdb to debug fairly early into the system boot. We only bother implementing this if polling is enabled since kgdb can't be enabled without that. Signed-off-by: Douglas Anderson <dianders@chromium.org> --- Changes in v2: None drivers/tty/serial/qcom_geni_serial.c | 32 +++++++++++++++++++++++++++ 1 file changed, 32 insertions(+)