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* [PATCH 2/6] ARM: PL011: Separate hardware FIFO size from TTY FIFO size
@ 2010-12-22 23:09 Russell King - ARM Linux
  0 siblings, 0 replies; 2+ messages in thread
From: Russell King - ARM Linux @ 2010-12-22 23:09 UTC (permalink / raw)
  To: linux-arm-kernel

With DMA support, we need to tell the TTY subsystem that the DMA buffer
is the size of the FIFO, otherwise things like tty_wait_until_sent()
will time out too early.  Keep (and use) the hardware value separately
from the port->fifosize.

This was part of a larger patch from Linus Walleij, with a little
modification.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 drivers/serial/amba-pl011.c |    8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/serial/amba-pl011.c b/drivers/serial/amba-pl011.c
index 6066b18..11cfa90 100644
--- a/drivers/serial/amba-pl011.c
+++ b/drivers/serial/amba-pl011.c
@@ -74,6 +74,7 @@ struct uart_amba_port {
 	unsigned int		ifls;		/* vendor-specific */
 	unsigned int		lcrh_tx;	/* vendor-specific */
 	unsigned int		lcrh_rx;	/* vendor-specific */
+	unsigned int		fifosize;	/* vendor-specific */
 	bool			oversampling;   /* vendor-specific */
 	bool			autorts;
 };
@@ -203,7 +204,7 @@ static void pl011_tx_chars(struct uart_amba_port *uap)
 		return;
 	}
 
-	count = uap->port.fifosize >> 1;
+	count = uap->fifosize >> 1;
 	do {
 		writew(xmit->buf[xmit->tail], uap->port.membase + UART01x_DR);
 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
@@ -536,7 +537,7 @@ pl011_set_termios(struct uart_port *port, struct ktermios *termios,
 		if (!(termios->c_cflag & PARODD))
 			lcr_h |= UART01x_LCRH_EPS;
 	}
-	if (port->fifosize > 1)
+	if (uap->fifosize > 1)
 		lcr_h |= UART01x_LCRH_FEN;
 
 	spin_lock_irqsave(&port->lock, flags);
@@ -866,12 +867,13 @@ static int pl011_probe(struct amba_device *dev, struct amba_id *id)
 	uap->lcrh_rx = vendor->lcrh_rx;
 	uap->lcrh_tx = vendor->lcrh_tx;
 	uap->oversampling = vendor->oversampling;
+	uap->fifosize = vendor->fifosize;
 	uap->port.dev = &dev->dev;
 	uap->port.mapbase = dev->res.start;
 	uap->port.membase = base;
 	uap->port.iotype = UPIO_MEM;
 	uap->port.irq = dev->irq[0];
-	uap->port.fifosize = vendor->fifosize;
+	uap->port.fifosize = uap->fifosize;
 	uap->port.ops = &amba_pl011_pops;
 	uap->port.flags = UPF_BOOT_AUTOCONF;
 	uap->port.line = i;
-- 
1.6.2.5

^ permalink raw reply related	[flat|nested] 2+ messages in thread
* [PATCH 0/6] PL011 DMA support
@ 2010-12-24 10:23 Russell King - ARM Linux
  2010-12-24 10:24 ` [PATCH 2/6] ARM: PL011: Separate hardware FIFO size from TTY FIFO size Russell King - ARM Linux
  0 siblings, 1 reply; 2+ messages in thread
From: Russell King - ARM Linux @ 2010-12-24 10:23 UTC (permalink / raw)
  To: linux-arm-kernel

Re-post of the previous set, but using writew() instead of writew_relaxed().
writew_relaxed() is not part of the MMIO accessor API, and so should
not be used in drivers which may be used on other architectures.

Also copying Dan for his review of the DMA engine use.

^ permalink raw reply	[flat|nested] 2+ messages in thread
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