| Message ID | 20221107171500.2537938-3-gsomlo@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | serial: liteuart: add IRQ support | expand |
On Thu, Nov 10, 2022 at 01:09:59AM +0000, Joel Stanley wrote: > On Mon, 7 Nov 2022 at 17:15, Gabriel Somlo <gsomlo@gmail.com> wrote: > > > > Move the character-receive (RX) loop to its own dedicated function, > > and (for now) call that from the poll timer, liteuart_timer(). > > > > This is in preparation for adding IRQ support to the receive path. > > > > Signed-off-by: Gabriel Somlo <gsomlo@gmail.com> > > --- > > drivers/tty/serial/liteuart.c | 25 +++++++++++++++---------- > > 1 file changed, 15 insertions(+), 10 deletions(-) > > > > diff --git a/drivers/tty/serial/liteuart.c b/drivers/tty/serial/liteuart.c > > index 4b9cca249828..90a29ed79bff 100644 > > --- a/drivers/tty/serial/liteuart.c > > +++ b/drivers/tty/serial/liteuart.c > > @@ -69,29 +69,34 @@ static struct uart_driver liteuart_driver = { > > #endif > > }; > > > > -static void liteuart_timer(struct timer_list *t) > > +static void liteuart_rx_chars(struct uart_port *port) > > { > > - struct liteuart_port *uart = from_timer(uart, t, timer); > > - struct uart_port *port = &uart->port; > > unsigned char __iomem *membase = port->membase; > > - unsigned int flg = TTY_NORMAL; > > - int ch; > > - unsigned long status; > > + unsigned int status; > > + unsigned char ch; > > u32, u8, void __iomem * would be better kernel types to use here. > > You've also changed ch from a signed 32 to an unsigned 8. uart_insert_char() expects both `status` and `ch` to be of type `unsigned int`. Switching `ch` to 8-bit was a typo, thanks for catching it! I'm going to use `unsigned int status, ch` in v3, to match the signature of `uart_insert_char()` -- hope that's OK. This will be a separate commit preceding the "move rx loop out of poll timer" change. > > > > while ((status = !litex_read8(membase + OFF_RXEMPTY)) == 1) { > > ch = litex_read8(membase + OFF_RXTX); > > port->icount.rx++; > > > > /* necessary for RXEMPTY to refresh its value */ > > - litex_write8(membase + OFF_EV_PENDING, EV_TX | EV_RX); > > + litex_write8(membase + OFF_EV_PENDING, EV_RX); > > You're no longer clearing EV_TX, but don't mention why (I understand > why with the context of the other changes, so perhaps add something to > this commit message). I'm adding a separate commit to document this (in v3) as well. Thanks, --Gabriel > > > > > /* no overflow bits in status */ > > if (!(uart_handle_sysrq_char(port, ch))) > > - uart_insert_char(port, status, 0, ch, flg); > > - > > - tty_flip_buffer_push(&port->state->port); > > + uart_insert_char(port, status, 0, ch, TTY_NORMAL); > > } > > > > + tty_flip_buffer_push(&port->state->port); > > +} > > + > > +static void liteuart_timer(struct timer_list *t) > > +{ > > + struct liteuart_port *uart = from_timer(uart, t, timer); > > + struct uart_port *port = &uart->port; > > + > > + liteuart_rx_chars(port); > > + > > mod_timer(&uart->timer, jiffies + uart_poll_timeout(port)); > > } > > > > -- > > 2.37.3 > >
diff --git a/drivers/tty/serial/liteuart.c b/drivers/tty/serial/liteuart.c index 4b9cca249828..90a29ed79bff 100644 --- a/drivers/tty/serial/liteuart.c +++ b/drivers/tty/serial/liteuart.c @@ -69,29 +69,34 @@ static struct uart_driver liteuart_driver = { #endif }; -static void liteuart_timer(struct timer_list *t) +static void liteuart_rx_chars(struct uart_port *port) { - struct liteuart_port *uart = from_timer(uart, t, timer); - struct uart_port *port = &uart->port; unsigned char __iomem *membase = port->membase; - unsigned int flg = TTY_NORMAL; - int ch; - unsigned long status; + unsigned int status; + unsigned char ch; while ((status = !litex_read8(membase + OFF_RXEMPTY)) == 1) { ch = litex_read8(membase + OFF_RXTX); port->icount.rx++; /* necessary for RXEMPTY to refresh its value */ - litex_write8(membase + OFF_EV_PENDING, EV_TX | EV_RX); + litex_write8(membase + OFF_EV_PENDING, EV_RX); /* no overflow bits in status */ if (!(uart_handle_sysrq_char(port, ch))) - uart_insert_char(port, status, 0, ch, flg); - - tty_flip_buffer_push(&port->state->port); + uart_insert_char(port, status, 0, ch, TTY_NORMAL); } + tty_flip_buffer_push(&port->state->port); +} + +static void liteuart_timer(struct timer_list *t) +{ + struct liteuart_port *uart = from_timer(uart, t, timer); + struct uart_port *port = &uart->port; + + liteuart_rx_chars(port); + mod_timer(&uart->timer, jiffies + uart_poll_timeout(port)); }
Move the character-receive (RX) loop to its own dedicated function, and (for now) call that from the poll timer, liteuart_timer(). This is in preparation for adding IRQ support to the receive path. Signed-off-by: Gabriel Somlo <gsomlo@gmail.com> --- drivers/tty/serial/liteuart.c | 25 +++++++++++++++---------- 1 file changed, 15 insertions(+), 10 deletions(-)