Commit fcfb1c39 authored by Jiri Slaby's avatar Jiri Slaby Committed by Greg Kroah-Hartman
Browse files

serial: pch: decomission pch_uart_hal_write() 



It's horrid and if we inline it into callers, we can get rid of a lot of
sugar around.

So:
* x_char handling becomes a single iowrite8.
* xmit->buf handling is a single loop simply writing characters one by
  one directly from the buf instead of complex cnt_to_end computations.
  Until the buf is empty or fifo size is reached.

Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220503080808.28332-2-jslaby@suse.cz


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d9f3af4f

drivers/tty/serial/pch_uart.c

+13 −33
Original line number Diff line number Diff line
@@ -550,18 +550,6 @@ static u8 pch_uart_hal_get_modem(struct eg20t_port *priv) 
	return (u8)msr;

}



static void pch_uart_hal_write(struct eg20t_port *priv,

			      const unsigned char *buf, int tx_size)

{

	int i;

	unsigned int thr;



	for (i = 0; i < tx_size;) {

		thr = buf[i++];

		iowrite8(thr, priv->membase + PCH_UART_THR);

	}

}



static int pch_uart_hal_read(struct eg20t_port *priv, unsigned char *buf,

			     int rx_size)

{
@@ -769,23 +757,21 @@ static void pch_dma_tx_complete(void *arg) 
	pch_uart_hal_enable_interrupt(priv, PCH_UART_HAL_TX_INT);

}



static int pop_tx(struct eg20t_port *priv, int size)

static bool pop_tx(struct eg20t_port *priv, unsigned int size)

{

	int count = 0;

	unsigned int count = 0;

	struct uart_port *port = &priv->port;

	struct circ_buf *xmit = &port->state->xmit;



	if (uart_tx_stopped(port) || uart_circ_empty(xmit))

	if (uart_tx_stopped(port))

		goto pop_tx_end;



	do {

		int cnt_to_end =

		    CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);

		int sz = min(size - count, cnt_to_end);

		pch_uart_hal_write(priv, &xmit->buf[xmit->tail], sz);

		xmit->tail = (xmit->tail + sz) & (UART_XMIT_SIZE - 1);

		count += sz;

	} while (!uart_circ_empty(xmit) && count < size);

	while (!uart_circ_empty(xmit) && count < size) {

		iowrite8(xmit->buf[xmit->tail], priv->membase + PCH_UART_THR);

		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);

		port->icount.tx++;

		count++;

	}



pop_tx_end:

	dev_dbg(priv->port.dev, "%d characters. Remained %d characters.(%lu)\n",
@@ -859,7 +845,6 @@ static unsigned int handle_tx(struct eg20t_port *priv) 
	struct uart_port *port = &priv->port;

	struct circ_buf *xmit = &port->state->xmit;

	int fifo_size;

	int tx_size;

	int size;

	int tx_empty;
@@ -874,7 +859,7 @@ static unsigned int handle_tx(struct eg20t_port *priv) 
	fifo_size = max(priv->fifo_size, 1);

	tx_empty = 1;

	if (port->x_char) {

		pch_uart_hal_write(priv, &port->x_char, 1);

		iowrite8(port->x_char, priv->membase + PCH_UART_THR);

		port->icount.tx++;

		port->x_char = 0;

		tx_empty = 0;
@@ -884,13 +869,8 @@ static unsigned int handle_tx(struct eg20t_port *priv) 
	size = min(xmit->head - xmit->tail, fifo_size);

	if (size < 0)

		size = fifo_size;

	if (size) {

		tx_size = pop_tx(priv, size);

		if (tx_size > 0) {

			port->icount.tx += tx_size;

	if (size && pop_tx(priv, size))

		tx_empty = 0;

		}

	}



	priv->tx_empty = tx_empty;
@@ -935,7 +915,7 @@ static unsigned int dma_handle_tx(struct eg20t_port *priv) 
	fifo_size = max(priv->fifo_size, 1);



	if (port->x_char) {

		pch_uart_hal_write(priv, &port->x_char, 1);

		iowrite8(port->x_char, priv->membase + PCH_UART_THR);

		port->icount.tx++;

		port->x_char = 0;

		fifo_size--;