2014-04-26 00:11:20

by Jon Ringle

Subject: [PATCH] serial: sc16is7xx: dynamically allocate tx/rx buffer

From: Jon Ringle <[email protected]>

This fixes the warnings:

drivers/tty/serial/sc16is7xx.c: In function 'sc16is7xx_handle_rx':
>> drivers/tty/serial/sc16is7xx.c:548:1: warning: 'sc16is7xx_handle_rx' uses dynamic stack allocation [enabled by default]
drivers/tty/serial/sc16is7xx.c: In function 'sc16is7xx_handle_tx':
>> drivers/tty/serial/sc16is7xx.c:589:1: warning: 'sc16is7xx_handle_tx' uses dynamic stack allocation [enabled by default]

Signed-off-by: Jon Ringle <[email protected]>
---
drivers/tty/serial/sc16is7xx.c | 17 ++++++++---------
1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 7206a64..880cedd 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -317,6 +317,7 @@ struct sc16is7xx_port {
#ifdef CONFIG_GPIOLIB
struct gpio_chip gpio;
#endif
+ unsigned char buf[SC16IS7XX_FIFO_SIZE];
struct sc16is7xx_one p[0];
};

@@ -471,16 +472,15 @@ static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen,
{
struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
unsigned int lsr = 0, ch, flag, bytes_read, i;
- u8 buf[port->fifosize];
bool read_lsr = (iir == SC16IS7XX_IIR_RLSE_SRC) ? true : false;

- if (unlikely(rxlen >= port->fifosize)) {
+ if (unlikely(rxlen >= sizeof(s->buf))) {
dev_warn_ratelimited(port->dev,
"Port %i: Possible RX FIFO overrun: %d\n",
port->line, rxlen);
port->icount.buf_overrun++;
/* Ensure sanity of RX level */
- rxlen = port->fifosize;
+ rxlen = sizeof(s->buf);
}

while (rxlen) {
@@ -493,12 +493,12 @@ static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen,
lsr = 0;

if (read_lsr) {
- buf[0] = sc16is7xx_port_read(port, SC16IS7XX_RHR_REG);
+ s->buf[0] = sc16is7xx_port_read(port, SC16IS7XX_RHR_REG);
bytes_read = 1;
} else {
regcache_cache_bypass(s->regmap, true);
regmap_raw_read(s->regmap, SC16IS7XX_RHR_REG,
- buf, rxlen);
+ s->buf, rxlen);
regcache_cache_bypass(s->regmap, false);
bytes_read = rxlen;
}
@@ -532,7 +532,7 @@ static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen,
}

for (i = 0; i < bytes_read; ++i) {
- ch = buf[i];
+ ch = s->buf[i];
if (uart_handle_sysrq_char(port, ch))
continue;

@@ -553,7 +553,6 @@ static void sc16is7xx_handle_tx(struct uart_port *port)
struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
struct circ_buf *xmit = &port->state->xmit;
unsigned int txlen, to_send, i;
- u8 buf[port->fifosize];

if (unlikely(port->x_char)) {
sc16is7xx_port_write(port, SC16IS7XX_THR_REG, port->x_char);
@@ -577,11 +576,11 @@ static void sc16is7xx_handle_tx(struct uart_port *port)

/* Convert to linear buffer */
for (i = 0; i < to_send; ++i) {
- buf[i] = xmit->buf[xmit->tail];
+ s->buf[i] = xmit->buf[xmit->tail];
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
}
regcache_cache_bypass(s->regmap, true);
- regmap_raw_write(s->regmap, SC16IS7XX_THR_REG, buf, to_send);
+ regmap_raw_write(s->regmap, SC16IS7XX_THR_REG, s->buf, to_send);
regcache_cache_bypass(s->regmap, false);
}

--
1.8.5.4