diff options
| author | John Ogness <john.ogness@linutronix.de> | 2025-01-07 22:32:59 +0106 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-01-10 16:08:25 +0100 |
| commit | 95a1b409ba08b602bf4464786ac74d21ae0acbf3 (patch) | |
| tree | bca4f2dea92068d46aa05aba0329f3e45724ec32 | |
| parent | 8d5cfb1fe5d8692b2de79b3831445be982167531 (diff) | |
serial: 8250: Use high-level writing function for FIFO
Currently serial8250_console_fifo_write() directly writes into
the UART_TX register rather than using the high-level function
serial8250_console_putchar(). This is because
serial8250_console_putchar() waits for the holding register to
become empty, which would defeat the purpose of the FIFO code.
Move the LSR_THRE waiting to a new function
serial8250_console_wait_putchar() so that the FIFO code can use
serial8250_console_putchar(). This will be particularly important
for a follow-up commit, where output bytes are inspected to track
newlines.
This is only refactoring and has no functional change.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20250107212702.169493-4-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/serial/8250/8250_port.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index ca8f6f3855eb..15abd95fcf06 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -3299,10 +3299,15 @@ EXPORT_SYMBOL_GPL(serial8250_set_defaults); static void serial8250_console_putchar(struct uart_port *port, unsigned char ch) { + serial_port_out(port, UART_TX, ch); +} + +static void serial8250_console_wait_putchar(struct uart_port *port, unsigned char ch) +{ struct uart_8250_port *up = up_to_u8250p(port); wait_for_xmitr(up, UART_LSR_THRE); - serial_port_out(port, UART_TX, ch); + serial8250_console_putchar(port, ch); } /* @@ -3352,6 +3357,7 @@ static void serial8250_console_fifo_write(struct uart_8250_port *up, { const char *end = s + count; unsigned int fifosize = up->tx_loadsz; + struct uart_port *port = &up->port; unsigned int tx_count = 0; bool cr_sent = false; unsigned int i; @@ -3362,10 +3368,10 @@ static void serial8250_console_fifo_write(struct uart_8250_port *up, for (i = 0; i < fifosize && s != end; ++i) { if (*s == '\n' && !cr_sent) { - serial_out(up, UART_TX, '\r'); + serial8250_console_putchar(port, '\r'); cr_sent = true; } else { - serial_out(up, UART_TX, *s++); + serial8250_console_putchar(port, *s++); cr_sent = false; } } @@ -3445,7 +3451,7 @@ void serial8250_console_write(struct uart_8250_port *up, const char *s, if (likely(use_fifo)) serial8250_console_fifo_write(up, s, count); else - uart_console_write(port, s, count, serial8250_console_putchar); + uart_console_write(port, s, count, serial8250_console_wait_putchar); /* * Finally, wait for transmitter to become empty |