Merge tag 'tty-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull TTY/serial patches from Greg KH:
 "tty and serial merge for 3.4-rc1

  Here's the big serial and tty merge for the 3.4-rc1 tree.

  There's loads of fixes and reworks in here from Jiri for the tty
  layer, and a number of patches from Alan to help try to wrestle the vt
  layer into a sane model.

  Other than that, lots of driver updates and fixes, and other minor
  stuff, all detailed in the shortlog."

* tag 'tty-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (132 commits)
  serial: pxa: add clk_prepare/clk_unprepare calls
  TTY: Wrong unicode value copied in con_set_unimap()
  serial: PL011: clear pending interrupts
  serial: bfin-uart: Don't access tty circular buffer in TX DMA interrupt after it is reset.
  vt: NULL dereference in vt_do_kdsk_ioctl()
  tty: serial: vt8500: fix annotations for probe/remove
  serial: remove back and forth conversions in serial_out_sync
  serial: use serial_port_in/out vs serial_in/out in 8250
  serial: introduce generic port in/out helpers
  serial: reduce number of indirections in 8250 code
  serial: delete useless void casts in 8250.c
  serial: make 8250's serial_in shareable to other drivers.
  serial: delete last unused traces of pausing I/O in 8250
  pch_uart: Add module parameter descriptions
  pch_uart: Use existing default_baud in setup_console
  pch_uart: Add user_uartclk parameter
  pch_uart: Add Fish River Island II uart clock quirks
  pch_uart: Use uartclk instead of base_baud
  mpc5200b/uart: select more tolerant uart prescaler on low baudrates
  tty: moxa: fix bit test in moxa_start()
  ...

1 files changed, 27 insertions, 5 deletions

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 6800f5f26241..20d795d9b591 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -827,7 +827,12 @@ static void pl011_dma_rx_callback(void *data)
 {
 	struct uart_amba_port *uap = data;
 	struct pl011_dmarx_data *dmarx = &uap->dmarx;
+	struct dma_chan *rxchan = dmarx->chan;
 	bool lastbuf = dmarx->use_buf_b;
+	struct pl011_sgbuf *sgbuf = dmarx->use_buf_b ?
+		&dmarx->sgbuf_b : &dmarx->sgbuf_a;
+	size_t pending;
+	struct dma_tx_state state;
 	int ret;
 
 	/*
@@ -838,11 +843,21 @@ static void pl011_dma_rx_callback(void *data)
 	 * we immediately trigger the next DMA job.
 	 */
 	spin_lock_irq(&uap->port.lock);
+	/*
+	 * Rx data can be taken by the UART interrupts during
+	 * the DMA irq handler. So we check the residue here.
+	 */
+	rxchan->device->device_tx_status(rxchan, dmarx->cookie, &state);
+	pending = sgbuf->sg.length - state.residue;
+	BUG_ON(pending > PL011_DMA_BUFFER_SIZE);
+	/* Then we terminate the transfer - we now know our residue */
+	dmaengine_terminate_all(rxchan);
+
 	uap->dmarx.running = false;
 	dmarx->use_buf_b = !lastbuf;
 	ret = pl011_dma_rx_trigger_dma(uap);
 
-	pl011_dma_rx_chars(uap, PL011_DMA_BUFFER_SIZE, lastbuf, false);
+	pl011_dma_rx_chars(uap, pending, lastbuf, false);
 	spin_unlock_irq(&uap->port.lock);
 	/*
 	 * Do this check after we picked the DMA chars so we don't
@@ -1381,6 +1396,10 @@ static int pl011_startup(struct uart_port *port)
 
 	uap->port.uartclk = clk_get_rate(uap->clk);
 
+	/* Clear pending error and receive interrupts */
+	writew(UART011_OEIS | UART011_BEIS | UART011_PEIS | UART011_FEIS |
+	       UART011_RTIS | UART011_RXIS, uap->port.membase + UART011_ICR);
+
 	/*
 	 * Allocate the IRQ
 	 */
@@ -1417,10 +1436,6 @@ static int pl011_startup(struct uart_port *port)
 	cr |= UART01x_CR_UARTEN | UART011_CR_RXE | UART011_CR_TXE;
 	writew(cr, uap->port.membase + UART011_CR);
 
-	/* Clear pending error interrupts */
-	writew(UART011_OEIS | UART011_BEIS | UART011_PEIS | UART011_FEIS,
-	       uap->port.membase + UART011_ICR);
-
 	/*
 	 * initialise the old status of the modem signals
 	 */
@@ -1435,6 +1450,9 @@ static int pl011_startup(struct uart_port *port)
 	 * as well.
 	 */
 	spin_lock_irq(&uap->port.lock);
+	/* Clear out any spuriously appearing RX interrupts */
+	 writew(UART011_RTIS | UART011_RXIS,
+		uap->port.membase + UART011_ICR);
 	uap->im = UART011_RTIM;
 	if (!pl011_dma_rx_running(uap))
 		uap->im |= UART011_RXIM;
@@ -1927,6 +1945,10 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
 		goto unmap;
 	}
 
+	/* Ensure interrupts from this UART are masked and cleared */
+	writew(0, uap->port.membase + UART011_IMSC);
+	writew(0xffff, uap->port.membase + UART011_ICR);
+
 	uap->vendor = vendor;
 	uap->lcrh_rx = vendor->lcrh_rx;
 	uap->lcrh_tx = vendor->lcrh_tx;