| Message ID | 3a5b27987c5b4fc5ec7dc7f58485db63057edbfe.1560338079.git.michal.simek@xilinx.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | serial: uartps: | expand |
On Wed, 2019-06-12 at 13:14 +0200, Michal Simek wrote: > From: Nava kishore Manne <nava.manne@xilinx.com> > > Trivial patch which fixes this checkpatch warning: > WARNING: Avoid multiple line dereference - prefer 'port->state->xmit.tail' > + port->state->xmit.buf[port->state->xmit. > + tail], port->membase + CDNS_UART_FIFO); > > Fixes: c8dbdc842d30 ("serial: xuartps: Rewrite the interrupt handling logic") > Signed-off-by: Nava kishore Manne <nava.manne@xilinx.com> > Signed-off-by: Michal Simek <michal.simek@xilinx.com> > --- > > Changes in v2: > - Split patch from v1 > - Add Fixes tag > > drivers/tty/serial/xilinx_uartps.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c > index c84db82bdaab..4cd20c036750 100644 > --- a/drivers/tty/serial/xilinx_uartps.c > +++ b/drivers/tty/serial/xilinx_uartps.c > @@ -319,8 +319,8 @@ static void cdns_uart_handle_tx(void *dev_id) > * register. > */ > writel( > - port->state->xmit.buf[port->state->xmit. > - tail], port->membase + CDNS_UART_FIFO); > + port->state->xmit.buf[port->state->xmit.tail], > + port->membase + CDNS_UART_FIFO); > > port->icount.tx++; Another way to rewrite this is to use a temporary for port->state->xmit and also return early on empty to avoid unnecessary indentation. Using a temporary can also reduce object size a bit by removing unnecessary dereferences: (defconfig x86-64) $ size drivers/tty/serial/xilinx_uartps.o* text data bss dec hex filename 26578 4632 320 31530 7b2a drivers/tty/serial/xilinx_uartps.o.new 26642 4632 320 31594 7b6a drivers/tty/serial/xilinx_uartps.o.old i.e.: --- drivers/tty/serial/xilinx_uartps.c | 54 ++++++++++++++++++-------------------- 1 file changed, 25 insertions(+), 29 deletions(-) diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c index 605354fd60b1..09b586aeeca3 100644 --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -305,40 +305,36 @@ static void cdns_uart_handle_rx(void *dev_id, unsigned int isrstatus) static void cdns_uart_handle_tx(void *dev_id) { struct uart_port *port = (struct uart_port *)dev_id; + struct circ_buf *xmit = &port->state->xmit; unsigned int numbytes; - if (uart_circ_empty(&port->state->xmit)) { + if (uart_circ_empty(xmit)) { writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_IDR); - } else { - numbytes = port->fifosize; - while (numbytes && !uart_circ_empty(&port->state->xmit) && - !(readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXFULL)) { - /* - * Get the data from the UART circular buffer - * and write it to the cdns_uart's TX_FIFO - * register. - */ - writel( - port->state->xmit.buf[port->state->xmit. - tail], port->membase + CDNS_UART_FIFO); - - port->icount.tx++; - - /* - * Adjust the tail of the UART buffer and wrap - * the buffer if it reaches limit. - */ - port->state->xmit.tail = - (port->state->xmit.tail + 1) & - (UART_XMIT_SIZE - 1); - - numbytes--; - } + return; + } + + numbytes = port->fifosize; + while (numbytes && !uart_circ_empty(xmit) && + !(readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXFULL)) { + /* + * Get the data from the UART circular buffer and write it + * to the cdns_uart's TX_FIFO register. + */ + writel(xmit->buf[xmit->tail], port->membase + CDNS_UART_FIFO); + + port->icount.tx++; + + /* + * Adjust the tail of the UART buffer and wrap the buffer + * if it reaches limit. + */ + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); - if (uart_circ_chars_pending( - &port->state->xmit) < WAKEUP_CHARS) - uart_write_wakeup(port); + numbytes--; } + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(port); } /**
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c index c84db82bdaab..4cd20c036750 100644 --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -319,8 +319,8 @@ static void cdns_uart_handle_tx(void *dev_id) * register. */ writel( - port->state->xmit.buf[port->state->xmit. - tail], port->membase + CDNS_UART_FIFO); + port->state->xmit.buf[port->state->xmit.tail], + port->membase + CDNS_UART_FIFO); port->icount.tx++;