@@ -978,6 +978,15 @@ static irqreturn_t lpuart_int(int irq, void *dev_id)
sts = readb(sport->port.membase + UARTSR1);
+ /* SysRq, using dma, check for linebreak by framing err. */
+ if (sts & UARTSR1_FE && sport->lpuart_dma_rx_use) {
+ readb(sport->port.membase + UARTDR);
+ uart_handle_break(&sport->port);
+ /* linebreak produces some garbage, removing it */
+ writeb(UARTCFIFO_RXFLUSH, sport->port.membase + UARTCFIFO);
+ return IRQ_HANDLED;
+ }
+
if (sts & UARTSR1_RDRF && !sport->lpuart_dma_rx_use)
lpuart_rxint(sport);
@@ -1006,6 +1015,37 @@ static irqreturn_t lpuart32_int(int irq, void *dev_id)
return IRQ_HANDLED;
}
+
+static inline void lpuart_handle_sysrq_chars(struct uart_port *port,
+ unsigned char *p, int count)
+{
+ while (count--) {
+ if (*p && uart_handle_sysrq_char(port, *p))
+ return;
+ p++;
+ }
+}
+
+static void lpuart_handle_sysrq(struct lpuart_port *sport)
+{
+ struct circ_buf *ring = &sport->rx_ring;
+ int count;
+
+ if (ring->head < ring->tail) {
+ count = sport->rx_sgl.length - ring->tail;
+ lpuart_handle_sysrq_chars(&sport->port,
+ ring->buf + ring->tail, count);
+ ring->tail = 0;
+ }
+
+ if (ring->head > ring->tail) {
+ count = ring->head - ring->tail;
+ lpuart_handle_sysrq_chars(&sport->port,
+ ring->buf + ring->tail, count);
+ ring->tail = ring->head;
+ }
+}
+
static void lpuart_copy_rx_to_tty(struct lpuart_port *sport)
{
struct tty_port *port = &sport->port.state->port;
@@ -1092,6 +1132,15 @@ static void lpuart_copy_rx_to_tty(struct lpuart_port *sport)
*/
ring->head = sport->rx_sgl.length - state.residue;
BUG_ON(ring->head > sport->rx_sgl.length);
+
+ /*
+ * Silent handling of keys pressed in the sysrq timeframe
+ */
+ if (sport->port.sysrq) {
+ lpuart_handle_sysrq(sport);
+ goto exit;
+ }
+
/*
* At this point ring->head may point to the first byte right after the
* last byte of the dma buffer:
@@ -1123,6 +1172,7 @@ static void lpuart_copy_rx_to_tty(struct lpuart_port *sport)
sport->port.icount.rx += count;
}
+exit:
dma_sync_sg_for_device(chan->device->dev, &sport->rx_sgl, 1,
DMA_FROM_DEVICE);
@@ -1559,6 +1609,7 @@ static void lpuart_tx_dma_startup(struct lpuart_port *sport)
static void lpuart_rx_dma_startup(struct lpuart_port *sport)
{
int ret;
+ unsigned char cr3;
if (!sport->dma_rx_chan)
goto err;
@@ -1575,6 +1626,12 @@ static void lpuart_rx_dma_startup(struct lpuart_port *sport)
sport->lpuart_dma_rx_use = true;
rx_dma_timer_init(sport);
+ if (sport->port.has_sysrq) {
+ cr3 = readb(sport->port.membase + UARTCR3);
+ cr3 |= UARTCR3_FEIE;
+ writeb(cr3, sport->port.membase + UARTCR3);
+ }
+
return;
err:
Add handling of magic sysrq keys when using dma/edma. Tested by sending BREAK followed by a sysrq command inside a 5 secs time window, by: echo 1 > /proc/sys/kernel/sysrq BREAK + h, t, e, b, c Tested also sending a command after 5 secs after BREAK, that's properly ignored. Signed-off-by: Angelo Dureghello <angelo.dureghello@timesys.com> --- drivers/tty/serial/fsl_lpuart.c | 57 +++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+)