svn commit: r259759 - in stable/10/sys: arm/at91 dev/uart

[Warner Losh]

Author: imp
Date: Mon Dec 23 01:24:32 2013
New Revision: 259759
URL: http://svnweb.freebsd.org/changeset/base/259759

Log:
  MFC r259685:
  
   Plumb the cn_grab and cn_ungrab routines down into the uart
   clients. Mask RX interrupts while grabbed on the atmel serial
   driver. This UART interrupts every character. When interrupts are
   enabled at the mountroot> prompt, this means the ISR eats the
   characters. Rather than try to create a cooperative buffering system
   for the low level kernel console, instead just mask out the ISR. For
   NS8250 and decsendents this isn't needed, since interrupts only happen
   after 14 or more characters (depending on the fifo settings). Plumb
   such that these are optional so there's no change in behavior for all
   the other UART clients. ddb worked on this platform because all
   interrupts were disabled while it was running, so this problem wasn't
   noticed. The mountroot> issue has been around for a very very long
   time.
  
  Approved by:	re@ (gjb@)

Modified:
  stable/10/sys/arm/at91/uart_dev_at91usart.c
  stable/10/sys/dev/uart/uart_cpu.h
  stable/10/sys/dev/uart/uart_tty.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/arm/at91/uart_dev_at91usart.c
==============================================================================
--- stable/10/sys/arm/at91/uart_dev_at91usart.c	Mon Dec 23 01:24:21 2013	(r259758)
+++ stable/10/sys/arm/at91/uart_dev_at91usart.c	Mon Dec 23 01:24:32 2013	(r259759)
@@ -219,6 +219,20 @@ at91_usart_param(struct uart_bas *bas, i
 	return (0);
 }
 
+static void
+at91_usart_grab(struct uart_bas *bas)
+{
+
+	WR4(bas, USART_IDR, USART_CSR_RXRDY);
+}
+
+static void
+at91_usart_ungrab(struct uart_bas *bas)
+{
+
+	WR4(bas, USART_IER, USART_CSR_RXRDY);
+}
+
 static struct uart_ops at91_usart_ops = {
 	.probe = at91_usart_probe,
 	.init = at91_usart_init,
@@ -226,6 +240,8 @@ static struct uart_ops at91_usart_ops = 
 	.putc = at91_usart_putc,
 	.rxready = at91_usart_rxready,
 	.getc = at91_usart_getc,
+	.grab = at91_usart_grab,
+	.ungrab = at91_usart_ungrab,
 };
 
 static int

Modified: stable/10/sys/dev/uart/uart_cpu.h
==============================================================================
--- stable/10/sys/dev/uart/uart_cpu.h	Mon Dec 23 01:24:21 2013	(r259758)
+++ stable/10/sys/dev/uart/uart_cpu.h	Mon Dec 23 01:24:32 2013	(r259759)
@@ -43,6 +43,8 @@ struct uart_ops {
 	void (*putc)(struct uart_bas *, int);
 	int (*rxready)(struct uart_bas *);
 	int (*getc)(struct uart_bas *, struct mtx *);
+	void (*grab)(struct uart_bas *);
+	void (*ungrab)(struct uart_bas *);
 };
 
 extern bus_space_tag_t uart_bus_space_io;
@@ -135,6 +137,27 @@ uart_putc(struct uart_devinfo *di, int c
 	uart_unlock(di->hwmtx);
 }
 
+static __inline void
+uart_grab(struct uart_devinfo *di)
+{
+
+	uart_lock(di->hwmtx);
+	if (di->ops->grab)
+		di->ops->grab(&di->bas);
+	uart_unlock(di->hwmtx);
+}
+
+static __inline void
+uart_ungrab(struct uart_devinfo *di)
+{
+
+	uart_lock(di->hwmtx);
+	if (di->ops->ungrab)
+		di->ops->ungrab(&di->bas);
+	uart_unlock(di->hwmtx);
+}
+
+
 static __inline int
 uart_rxready(struct uart_devinfo *di)
 {

Modified: stable/10/sys/dev/uart/uart_tty.c
==============================================================================
--- stable/10/sys/dev/uart/uart_tty.c	Mon Dec 23 01:24:21 2013	(r259758)
+++ stable/10/sys/dev/uart/uart_tty.c	Mon Dec 23 01:24:32 2013	(r259759)
@@ -112,11 +112,15 @@ uart_cnterm(struct consdev *cp)
 static void
 uart_cngrab(struct consdev *cp)
 {
+
+	uart_grab(cp->cn_arg);
 }
 
 static void
 uart_cnungrab(struct consdev *cp)
 {
+
+	uart_ungrab(cp->cn_arg);
 }
 
 static void