[PATCH v4 0/3] rework quirks for the "kt" serial port

[PATCH v4 0/3] rework quirks for the "kt" serial port

[Dan Williams]

Changes since v3: http://marc.info/?l=linux-serial&m=133400008811070&w=2

* Cleaned up "tegra, serial8250: add ->handle_break() uart_port op" to
  incorporate Stephen's feedback of just using CONFIG_ARCH_TEGRA instead
  of adding CONFIG_SERIAL_TEGRA.

* Added Arnd's ack

* The other two patches have not changed.

---

Dan Williams (2):
      tegra, serial8250: add ->handle_break() uart_port op
      serial/8250_pci: fix suspend/resume vs init/exit quirks

Sudhakar Mamillapalli (1):
      serial/8250_pci: Clear FIFOs for Intel ME Serial Over Lan device on BI


 arch/arm/mach-tegra/board-harmony.c   |    2 +
 arch/arm/mach-tegra/board-paz00.c     |    3 ++
 arch/arm/mach-tegra/board-seaboard.c  |    2 +
 arch/arm/mach-tegra/board-trimslice.c |    2 +
 drivers/tty/serial/8250/8250.c        |   44 ++++++++++----------------------
 drivers/tty/serial/8250/8250.h        |    2 +
 drivers/tty/serial/8250/8250_pci.c    |   45 +++++++++++++++++++++++++++++++++
 drivers/tty/serial/of_serial.c        |   26 +++++++++++++++++++
 include/linux/of_serial.h             |   17 ++++++++++++
 include/linux/serial_8250.h           |    1 +
 include/linux/serial_core.h           |    5 ++++
 11 files changed, 118 insertions(+), 31 deletions(-)
 create mode 100644 include/linux/of_serial.h

[PATCH v4 1/3] tegra, serial8250: add ->handle_break() uart_port op

[Dan Williams]

The "KT" serial port has another use case for a "received break" quirk,
so before adding another special case to the 8250 core take this
opportunity to push such quirks out of the core and into a uart_port op.

Stephen says:
"If the callback function is to no longer live in 8250.c itself,
 arch/arm/mach-tegra/devices.c isn't logically a good place to put it,
 and that file will be going away once we get rid of all the board files
 and move solely to device tree."

...so since 8250_pci.c houses all the quirks for pci serial devices this
quirk is similarly housed in of_serial.c.  Once the open firmware
conversion completes the infrastructure details
(include/linux/of_serial.h, and the export) can all be removed to make
this self contained to of_serial.c.

Cc: Nhan H Mai <nhan.h.mai@intel.com>
Cc: Colin Cross <ccross@android.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Stephen Warren <swarren@nvidia.com>
[stephen: kill CONFIG_SERIAL_TEGRA in favor just using CONFIG_ARCH_TEGRA]
Cc: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Sudhakar Mamillapalli <sudhakar@fb.com>
Reported-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 arch/arm/mach-tegra/board-harmony.c   |    2 ++
 arch/arm/mach-tegra/board-paz00.c     |    3 +++
 arch/arm/mach-tegra/board-seaboard.c  |    2 ++
 arch/arm/mach-tegra/board-trimslice.c |    2 ++
 drivers/tty/serial/8250/8250.c        |   34 +++------------------------------
 drivers/tty/serial/of_serial.c        |   26 +++++++++++++++++++++++++
 include/linux/of_serial.h             |   17 +++++++++++++++++
 include/linux/serial_8250.h           |    1 +
 include/linux/serial_core.h           |    5 +++++
 9 files changed, 61 insertions(+), 31 deletions(-)
 create mode 100644 include/linux/of_serial.h

diff --git a/arch/arm/mach-tegra/board-harmony.c b/arch/arm/mach-tegra/board-harmony.c
index c00aadb..222182e 100644
--- a/arch/arm/mach-tegra/board-harmony.c
+++ b/arch/arm/mach-tegra/board-harmony.c
@@ -19,6 +19,7 @@
 #include <linux/init.h>
 #include <linux/platform_device.h>
 #include <linux/serial_8250.h>
+#include <linux/of_serial.h>
 #include <linux/clk.h>
 #include <linux/dma-mapping.h>
 #include <linux/pda_power.h>
@@ -52,6 +53,7 @@ static struct plat_serial8250_port debug_uart_platform_data[] = {
 		.irq		= INT_UARTD,
 		.flags		= UPF_BOOT_AUTOCONF | UPF_FIXED_TYPE,
 		.type		= PORT_TEGRA,
+		.handle_break	= tegra_serial_handle_break,
 		.iotype		= UPIO_MEM,
 		.regshift	= 2,
 		.uartclk	= 216000000,
diff --git a/arch/arm/mach-tegra/board-paz00.c b/arch/arm/mach-tegra/board-paz00.c
index 330afdf..d0735c7 100644
--- a/arch/arm/mach-tegra/board-paz00.c
+++ b/arch/arm/mach-tegra/board-paz00.c
@@ -21,6 +21,7 @@
 #include <linux/init.h>
 #include <linux/platform_device.h>
 #include <linux/serial_8250.h>
+#include <linux/of_serial.h>
 #include <linux/clk.h>
 #include <linux/dma-mapping.h>
 #include <linux/gpio_keys.h>
@@ -55,6 +56,7 @@ static struct plat_serial8250_port debug_uart_platform_data[] = {
 		.irq		= INT_UARTA,
 		.flags		= UPF_BOOT_AUTOCONF | UPF_FIXED_TYPE,
 		.type		= PORT_TEGRA,
+		.handle_break	= tegra_serial_handle_break,
 		.iotype		= UPIO_MEM,
 		.regshift	= 2,
 		.uartclk	= 216000000,
@@ -65,6 +67,7 @@ static struct plat_serial8250_port debug_uart_platform_data[] = {
 		.irq		= INT_UARTC,
 		.flags		= UPF_BOOT_AUTOCONF | UPF_FIXED_TYPE,
 		.type		= PORT_TEGRA,
+		.handle_break	= tegra_serial_handle_break,
 		.iotype		= UPIO_MEM,
 		.regshift	= 2,
 		.uartclk	= 216000000,
diff --git a/arch/arm/mach-tegra/board-seaboard.c b/arch/arm/mach-tegra/board-seaboard.c
index d669847..5b687b8 100644
--- a/arch/arm/mach-tegra/board-seaboard.c
+++ b/arch/arm/mach-tegra/board-seaboard.c
@@ -18,6 +18,7 @@
 #include <linux/init.h>
 #include <linux/platform_device.h>
 #include <linux/serial_8250.h>
+#include <linux/of_serial.h>
 #include <linux/i2c.h>
 #include <linux/delay.h>
 #include <linux/input.h>
@@ -47,6 +48,7 @@ static struct plat_serial8250_port debug_uart_platform_data[] = {
 		/* Memory and IRQ filled in before registration */
 		.flags		= UPF_BOOT_AUTOCONF | UPF_FIXED_TYPE,
 		.type		= PORT_TEGRA,
+		.handle_break	= tegra_serial_handle_break,
 		.iotype		= UPIO_MEM,
 		.regshift	= 2,
 		.uartclk	= 216000000,
diff --git a/arch/arm/mach-tegra/board-trimslice.c b/arch/arm/mach-tegra/board-trimslice.c
index cd52820..f735858 100644
--- a/arch/arm/mach-tegra/board-trimslice.c
+++ b/arch/arm/mach-tegra/board-trimslice.c
@@ -22,6 +22,7 @@
 #include <linux/init.h>
 #include <linux/platform_device.h>
 #include <linux/serial_8250.h>
+#include <linux/of_serial.h>
 #include <linux/io.h>
 #include <linux/i2c.h>
 #include <linux/gpio.h>
@@ -48,6 +49,7 @@ static struct plat_serial8250_port debug_uart_platform_data[] = {
 		.irq		= INT_UARTA,
 		.flags		= UPF_BOOT_AUTOCONF | UPF_FIXED_TYPE,
 		.type		= PORT_TEGRA,
+		.handle_break	= tegra_serial_handle_break,
 		.iotype		= UPIO_MEM,
 		.regshift	= 2,
 		.uartclk	= 216000000,
diff --git a/drivers/tty/serial/8250/8250.c b/drivers/tty/serial/8250/8250.c
index 5c27f7e..cbd94c3 100644
--- a/drivers/tty/serial/8250/8250.c
+++ b/drivers/tty/serial/8250/8250.c
@@ -1332,27 +1332,6 @@ static void serial8250_enable_ms(struct uart_port *port)
 }
 
 /*
- * Clear the Tegra rx fifo after a break
- *
- * FIXME: This needs to become a port specific callback once we have a
- * framework for this
- */
-static void clear_rx_fifo(struct uart_8250_port *up)
-{
-	unsigned int status, tmout = 10000;
-	do {
-		status = serial_in(up, UART_LSR);
-		if (status & (UART_LSR_FIFOE | UART_LSR_BRK_ERROR_BITS))
-			status = serial_in(up, UART_RX);
-		else
-			break;
-		if (--tmout == 0)
-			break;
-		udelay(1);
-	} while (1);
-}
-
-/*
  * serial8250_rx_chars: processes according to the passed in LSR
  * value, and returns the remaining LSR bits not handled
  * by this Rx routine.
@@ -1386,20 +1365,10 @@ serial8250_rx_chars(struct uart_8250_port *up, unsigned char lsr)
 		up->lsr_saved_flags = 0;
 
 		if (unlikely(lsr & UART_LSR_BRK_ERROR_BITS)) {
-			/*
-			 * For statistics only
-			 */
 			if (lsr & UART_LSR_BI) {
 				lsr &= ~(UART_LSR_FE | UART_LSR_PE);
 				port->icount.brk++;
 				/*
-				 * If tegra port then clear the rx fifo to
-				 * accept another break/character.
-				 */
-				if (port->type == PORT_TEGRA)
-					clear_rx_fifo(up);
-
-				/*
 				 * We do the SysRQ and SAK checking
 				 * here because otherwise the break
 				 * may get masked by ignore_status_mask
@@ -3037,6 +3006,7 @@ static int __devinit serial8250_probe(struct platform_device *dev)
 		port.serial_in		= p->serial_in;
 		port.serial_out		= p->serial_out;
 		port.handle_irq		= p->handle_irq;
+		port.handle_break	= p->handle_break;
 		port.set_termios	= p->set_termios;
 		port.pm			= p->pm;
 		port.dev		= &dev->dev;
@@ -3209,6 +3179,8 @@ int serial8250_register_port(struct uart_port *port)
 			uart->port.set_termios = port->set_termios;
 		if (port->pm)
 			uart->port.pm = port->pm;
+		if (port->handle_break)
+			uart->port.handle_break = port->handle_break;
 
 		if (serial8250_isa_config != NULL)
 			serial8250_isa_config(0, &uart->port,
diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c
index e8c9cee..5410c06 100644
--- a/drivers/tty/serial/of_serial.c
+++ b/drivers/tty/serial/of_serial.c
@@ -12,10 +12,13 @@
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/slab.h>
+#include <linux/delay.h>
 #include <linux/serial_core.h>
 #include <linux/serial_8250.h>
+#include <linux/serial_reg.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
+#include <linux/of_serial.h>
 #include <linux/of_platform.h>
 #include <linux/nwpserial.h>
 
@@ -24,6 +27,26 @@ struct of_serial_info {
 	int line;
 };
 
+#ifdef CONFIG_ARCH_TEGRA
+void tegra_serial_handle_break(struct uart_port *p)
+{
+	unsigned int status, tmout = 10000;
+
+	do {
+		status = p->serial_in(p, UART_LSR);
+		if (status & (UART_LSR_FIFOE | UART_LSR_BRK_ERROR_BITS))
+			status = p->serial_in(p, UART_RX);
+		else
+			break;
+		if (--tmout == 0)
+			break;
+		udelay(1);
+	} while (1);
+}
+/* FIXME remove this export when tegra finishes conversion to open firmware */
+EXPORT_SYMBOL_GPL(tegra_serial_handle_break);
+#endif
+
 /*
  * Fill a struct uart_port for a given device node
  */
@@ -84,6 +107,9 @@ static int __devinit of_platform_serial_setup(struct platform_device *ofdev,
 		| UPF_FIXED_PORT | UPF_FIXED_TYPE;
 	port->dev = &ofdev->dev;
 
+	if (type == PORT_TEGRA)
+		port->handle_break = tegra_serial_handle_break;
+
 	return 0;
 }
 
diff --git a/include/linux/of_serial.h b/include/linux/of_serial.h
new file mode 100644
index 0000000..4a73ed8
--- /dev/null
+++ b/include/linux/of_serial.h
@@ -0,0 +1,17 @@
+#ifndef __LINUX_OF_SERIAL_H
+#define __LINUX_OF_SERIAL_H
+
+/*
+ * FIXME remove this file when tegra finishes conversion to open firmware,
+ * expectation is that all quirks will then be self-contained in
+ * drivers/tty/serial/of_serial.c.
+ */
+#ifdef CONFIG_ARCH_TEGRA
+extern void tegra_serial_handle_break(struct uart_port *port);
+#else
+static inline void tegra_serial_handle_break(struct uart_port *port)
+{
+}
+#endif
+
+#endif /* __LINUX_OF_SERIAL */
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index 8f012f8..a522fd9 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -38,6 +38,7 @@ struct plat_serial8250_port {
 	int		(*handle_irq)(struct uart_port *);
 	void		(*pm)(struct uart_port *, unsigned int state,
 			      unsigned old);
+	void		(*handle_break)(struct uart_port *);
 };
 
 /*
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 2db407a..65db992 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -310,6 +310,7 @@ struct uart_port {
 	int			(*handle_irq)(struct uart_port *);
 	void			(*pm)(struct uart_port *, unsigned int state,
 				      unsigned int old);
+	void			(*handle_break)(struct uart_port *);
 	unsigned int		irq;			/* irq number */
 	unsigned long		irqflags;		/* irq flags  */
 	unsigned int		uartclk;		/* base uart clock */
@@ -533,6 +534,10 @@ uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
 static inline int uart_handle_break(struct uart_port *port)
 {
 	struct uart_state *state = port->state;
+
+	if (port->handle_break)
+		port->handle_break(port);
+
 #ifdef SUPPORT_SYSRQ
 	if (port->cons && port->cons->index == port->line) {
 		if (!port->sysrq) {

Re: [PATCH v4 1/3] tegra, serial8250: add ->handle_break() uart_port op

[Stephen Warren]

On 04/10/2012 03:10 PM, Dan Williams wrote:
> The "KT" serial port has another use case for a "received break" quirk,
> so before adding another special case to the 8250 core take this
> opportunity to push such quirks out of the core and into a uart_port op.
> 
> Stephen says:
> "If the callback function is to no longer live in 8250.c itself,
>  arch/arm/mach-tegra/devices.c isn't logically a good place to put it,
>  and that file will be going away once we get rid of all the board files
>  and move solely to device tree."
> 
> ...so since 8250_pci.c houses all the quirks for pci serial devices this
> quirk is similarly housed in of_serial.c.  Once the open firmware
> conversion completes the infrastructure details
> (include/linux/of_serial.h, and the export) can all be removed to make
> this self contained to of_serial.c.

Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>

[PATCH v4 2/3] serial/8250_pci: Clear FIFOs for Intel ME Serial Over Lan device on BI

[Dan Williams]

From: Sudhakar Mamillapalli <sudhakar@fb.com>

When using Serial Over Lan (SOL) over the virtual serial port in a Intel
management engine (ME) device, on device reset the serial FIFOs need to
be cleared to keep the FIFO indexes in-sync between the host and the
engine.

On a reset the serial device assertes BI, so using that as a cue FIFOs
are cleared.  So for this purpose a new handle_break callback has been
added.  One other problem is that the serial registers might temporarily
go to 0 on reset of this device.  So instead of using the IER register
read, if 0 returned use the ier value in uart_8250_port. This is hidden
under a custom serial_in.

Cc: Nhan H Mai <nhan.h.mai@intel.com>
Signed-off-by: Sudhakar Mamillapalli <sudhakar@fb.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/tty/serial/8250/8250.c     |   10 +++++++++
 drivers/tty/serial/8250/8250.h     |    2 ++
 drivers/tty/serial/8250/8250_pci.c |   39 ++++++++++++++++++++++++++++++++++++
 3 files changed, 51 insertions(+)

diff --git a/drivers/tty/serial/8250/8250.c b/drivers/tty/serial/8250/8250.c
index cbd94c3..182efcc 100644
--- a/drivers/tty/serial/8250/8250.c
+++ b/drivers/tty/serial/8250/8250.c
@@ -568,6 +568,16 @@ static void serial8250_clear_fifos(struct uart_8250_port *p)
 	}
 }
 
+void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p)
+{
+	unsigned char fcr;
+
+	serial8250_clear_fifos(p);
+	fcr = uart_config[p->port.type].fcr;
+	serial_out(p, UART_FCR, fcr);
+}
+EXPORT_SYMBOL_GPL(serial8250_clear_and_reinit_fifos);
+
 /*
  * IER sleep support.  UARTs which have EFRs need the "extended
  * capability" bit enabled.  Note that on XR16C850s, we need to
diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index 2868a1d..c9d0ebe 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -96,6 +96,8 @@ static inline void serial_out(struct uart_8250_port *up, int offset, int value)
 	up->port.serial_out(&up->port, offset, value);
 }
 
+void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p);
+
 #if defined(__alpha__) && !defined(CONFIG_PCI)
 /*
  * Digital did something really horribly wrong with the OUT1 and OUT2
diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
index 858dca8..024551a 100644
--- a/drivers/tty/serial/8250/8250_pci.c
+++ b/drivers/tty/serial/8250/8250_pci.c
@@ -17,6 +17,7 @@
 #include <linux/slab.h>
 #include <linux/delay.h>
 #include <linux/tty.h>
+#include <linux/serial_reg.h>
 #include <linux/serial_core.h>
 #include <linux/8250_pci.h>
 #include <linux/bitops.h>
@@ -1092,11 +1093,49 @@ static int skip_tx_en_setup(struct serial_private *priv,
 	return pci_default_setup(priv, board, port, idx);
 }
 
+static void kt_handle_break(struct uart_port *p)
+{
+	struct uart_8250_port *up =
+		container_of(p, struct uart_8250_port, port);
+	/*
+	 * On receipt of a BI, serial device in Intel ME (Intel
+	 * management engine) needs to have its fifos cleared for sane
+	 * SOL (Serial Over Lan) output.
+	 */
+	serial8250_clear_and_reinit_fifos(up);
+}
+
+static unsigned int kt_serial_in(struct uart_port *p, int offset)
+{
+	struct uart_8250_port *up =
+		container_of(p, struct uart_8250_port, port);
+	unsigned int val;
+
+	/*
+	 * When the Intel ME (management engine) gets reset its serial
+	 * port registers could return 0 momentarily.  Functions like
+	 * serial8250_console_write, read and save the IER, perform
+	 * some operation and then restore it.  In order to avoid
+	 * setting IER register inadvertently to 0, if the value read
+	 * is 0, double check with ier value in uart_8250_port and use
+	 * that instead.  up->ier should be the same value as what is
+	 * currently configured.
+	 */
+	val = inb(p->iobase + offset);
+	if (offset == UART_IER) {
+		if (val == 0)
+			val = up->ier;
+	}
+	return val;
+}
+
 static int kt_serial_setup(struct serial_private *priv,
 			   const struct pciserial_board *board,
 			   struct uart_port *port, int idx)
 {
 	port->flags |= UPF_BUG_THRE;
+	port->serial_in = kt_serial_in;
+	port->handle_break = kt_handle_break;
 	return skip_tx_en_setup(priv, board, port, idx);
 }
 

Re: [PATCH v4 2/3] serial/8250_pci: Clear FIFOs for Intel ME Serial Over Lan device on BI

[Greg KH]

On Tue, Apr 10, 2012 at 02:10:58PM -0700, Dan Williams wrote:
> From: Sudhakar Mamillapalli <sudhakar@fb.com>
> 
> When using Serial Over Lan (SOL) over the virtual serial port in a Intel
> management engine (ME) device, on device reset the serial FIFOs need to
> be cleared to keep the FIFO indexes in-sync between the host and the
> engine.
> 
> On a reset the serial device assertes BI, so using that as a cue FIFOs
> are cleared.  So for this purpose a new handle_break callback has been
> added.  One other problem is that the serial registers might temporarily
> go to 0 on reset of this device.  So instead of using the IER register
> read, if 0 returned use the ier value in uart_8250_port. This is hidden
> under a custom serial_in.
> 
> Cc: Nhan H Mai <nhan.h.mai@intel.com>
> Signed-off-by: Sudhakar Mamillapalli <sudhakar@fb.com>
> Acked-by: Alan Cox <alan@linux.intel.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>

What tree did you make this against?

It fails with:
patching file drivers/tty/serial/8250/8250.c
patching file drivers/tty/serial/8250/8250.h
patching file drivers/tty/serial/8250/8250_pci.c
Hunk #2 FAILED at 1093.
1 out of 2 hunks FAILED -- saving rejects to file drivers/tty/serial/8250/8250_pci.c.rej

While that file hasn't been changed since it was moved to that location.

Any ideas?

Because of this, I've only applied your first patch in this series, not
the last two.

thanks,

greg k-h

Re: [PATCH v4 2/3] serial/8250_pci: Clear FIFOs for Intel ME Serial Over Lan device on BI

[Dan Williams]

On Wed, Apr 18, 2012 at 3:12 PM, Greg KH <gregkh@linuxfoundation.org> wrote:
> On Tue, Apr 10, 2012 at 02:10:58PM -0700, Dan Williams wrote:
>> From: Sudhakar Mamillapalli <sudhakar@fb.com>
>>
>> When using Serial Over Lan (SOL) over the virtual serial port in a Intel
>> management engine (ME) device, on device reset the serial FIFOs need to
>> be cleared to keep the FIFO indexes in-sync between the host and the
>> engine.
>>
>> On a reset the serial device assertes BI, so using that as a cue FIFOs
>> are cleared.  So for this purpose a new handle_break callback has been
>> added.  One other problem is that the serial registers might temporarily
>> go to 0 on reset of this device.  So instead of using the IER register
>> read, if 0 returned use the ier value in uart_8250_port. This is hidden
>> under a custom serial_in.
>>
>> Cc: Nhan H Mai <nhan.h.mai@intel.com>
>> Signed-off-by: Sudhakar Mamillapalli <sudhakar@fb.com>
>> Acked-by: Alan Cox <alan@linux.intel.com>
>> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
>
> What tree did you make this against?
>
> It fails with:
> patching file drivers/tty/serial/8250/8250.c
> patching file drivers/tty/serial/8250/8250.h
> patching file drivers/tty/serial/8250/8250_pci.c
> Hunk #2 FAILED at 1093.
> 1 out of 2 hunks FAILED -- saving rejects to file drivers/tty/serial/8250/8250_pci.c.rej
>
> While that file hasn't been changed since it was moved to that location.
>
> Any ideas?

Hmm, I think this is because this patch depends on the reverts went
into 3.4 via tty-linus.

On my internal tree I have the following against 3.4-rc2

48013c6 Revert "serial/8250_pci: init-quirk msi support for kt serial
controller"
0f4149f Revert "serial/8250_pci: setup-quirk workaround for the kt
serial controller"
5580b22 serial/8250_pci: add a "force background timer" flag and use
it for the "kt" serial port
d8a8351 tegra, serial8250: add ->handle_break() uart_port op
1d9aafe serial/8250_pci: Clear FIFOs for Intel ME Serial Over Lan device on BI
d4cb218 serial/8250_pci: fix suspend/resume vs init/exit quirks

> Because of this, I've only applied your first patch in this series, not
> the last two.

Not sure how these things are handled in tty.git, backmerge?

--
Dan

Re: [PATCH v4 2/3] serial/8250_pci: Clear FIFOs for Intel ME Serial Over Lan device on BI

[Greg KH]

On Wed, Apr 18, 2012 at 03:36:40PM -0700, Dan Williams wrote:
> On Wed, Apr 18, 2012 at 3:12 PM, Greg KH <gregkh@linuxfoundation.org> wrote:
> > On Tue, Apr 10, 2012 at 02:10:58PM -0700, Dan Williams wrote:
> >> From: Sudhakar Mamillapalli <sudhakar@fb.com>
> >>
> >> When using Serial Over Lan (SOL) over the virtual serial port in a Intel
> >> management engine (ME) device, on device reset the serial FIFOs need to
> >> be cleared to keep the FIFO indexes in-sync between the host and the
> >> engine.
> >>
> >> On a reset the serial device assertes BI, so using that as a cue FIFOs
> >> are cleared.  So for this purpose a new handle_break callback has been
> >> added.  One other problem is that the serial registers might temporarily
> >> go to 0 on reset of this device.  So instead of using the IER register
> >> read, if 0 returned use the ier value in uart_8250_port. This is hidden
> >> under a custom serial_in.
> >>
> >> Cc: Nhan H Mai <nhan.h.mai@intel.com>
> >> Signed-off-by: Sudhakar Mamillapalli <sudhakar@fb.com>
> >> Acked-by: Alan Cox <alan@linux.intel.com>
> >> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> >
> > What tree did you make this against?
> >
> > It fails with:
> > patching file drivers/tty/serial/8250/8250.c
> > patching file drivers/tty/serial/8250/8250.h
> > patching file drivers/tty/serial/8250/8250_pci.c
> > Hunk #2 FAILED at 1093.
> > 1 out of 2 hunks FAILED -- saving rejects to file drivers/tty/serial/8250/8250_pci.c.rej
> >
> > While that file hasn't been changed since it was moved to that location.
> >
> > Any ideas?
> 
> Hmm, I think this is because this patch depends on the reverts went
> into 3.4 via tty-linus.

Ah, ok, that makes more sense, let me go merge 3.4-rc3 into tty-next and
see if that solves the problem...

Yup, it did, thanks, I'll go apply these two patches now, sorry for the
noise.

greg k-h

[PATCH v4 3/3] serial/8250_pci: fix suspend/resume vs init/exit quirks

[Dan Williams]

Commit e86ff4a6 "serial/8250_pci: init-quirk msi support for kt serial
controller" introduced a regression in suspend/resume by causing msi's
to be enabled twice without an intervening disable.

00:16.3 Serial controller: Intel Corporation Patsburg KT Controller (rev 05) (prog-if 02 [16550])
       Subsystem: Intel Corporation Device 7270
       Flags: bus master, 66MHz, fast devsel, latency 0, IRQ 72
       I/O ports at 4080 [size=8]
       Memory at d1c30000 (32-bit, non-prefetchable) [size=4K]
       Capabilities: [c8] Power Management version 3
       Capabilities: [d0] MSI: Enable+ Count=1/1 Maskable- 64bit+
       Kernel driver in use: serial

[  365.250523] sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:16.3/msi_irqs'
[  365.250525] Modules linked in: nls_utf8 ipv6 uinput sg iTCO_wdt
  iTCO_vendor_support ioatdma dca i2c_i801 i2c_core wmi sd_mod ahci libahci isci
  libsas libata scsi_transport_sas [last unloaded: scsi_wait_scan]
[  365.250540] Pid: 9030, comm: kworker/u:1 Tainted: G        W    3.3.0-isci-3.0.213+ #1
[  365.250542] Call Trace:
[  365.250545]  [<ffffffff8115e955>] ? sysfs_add_one+0x99/0xad
[  365.250548]  [<ffffffff8102db8b>] warn_slowpath_common+0x85/0x9e
[  365.250551]  [<ffffffff8102dc96>] warn_slowpath_fmt+0x6e/0x70
[  365.250555]  [<ffffffff8115e8fa>] ? sysfs_add_one+0x3e/0xad
[  365.250558]  [<ffffffff8115e8b4>] ? sysfs_pathname+0x3c/0x44
[  365.250561]  [<ffffffff8115e8b4>] ? sysfs_pathname+0x3c/0x44
[  365.250564]  [<ffffffff8115e8b4>] ? sysfs_pathname+0x3c/0x44
[  365.250567]  [<ffffffff8115e8b4>] ? sysfs_pathname+0x3c/0x44
[  365.250570]  [<ffffffff8115e955>] sysfs_add_one+0x99/0xad
[  365.250573]  [<ffffffff8115f031>] create_dir+0x72/0xa5
[  365.250577]  [<ffffffff8115f194>] sysfs_create_dir+0xa2/0xbe
[  365.250581]  [<ffffffff81262463>] kobject_add_internal+0x126/0x1f8
[  365.250585]  [<ffffffff8126255b>] kset_register+0x26/0x3f
[  365.250588]  [<ffffffff8126275a>] kset_create_and_add+0x62/0x7c
[  365.250592]  [<ffffffff81293619>] populate_msi_sysfs+0x34/0x103
[  365.250595]  [<ffffffff81293e1c>] pci_enable_msi_block+0x1b3/0x216
[  365.250599]  [<ffffffff81303f7c>] try_enable_msi+0x13/0x17
[  365.250603]  [<ffffffff81303fb3>] pciserial_resume_ports+0x21/0x42
[  365.250607]  [<ffffffff81304041>] pciserial_resume_one+0x50/0x57
[  365.250610]  [<ffffffff81283e1a>] pci_legacy_resume+0x38/0x47
[  365.250613]  [<ffffffff81283e7d>] pci_pm_restore+0x54/0x87
[  365.250616]  [<ffffffff81283e29>] ? pci_legacy_resume+0x47/0x47
[  365.250619]  [<ffffffff8131e9e8>] dpm_run_callback+0x48/0x7b
[  365.250623]  [<ffffffff8131f39a>] device_resume+0x342/0x394
[  365.250626]  [<ffffffff8131f5b7>] async_resume+0x21/0x49

That patch has since been reverted, but by inspection it seems that
pciserial_suspend_ports() should be invoking .exit() quirks to release
resources acquired during .init().

Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/tty/serial/8250/8250_pci.c |    6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
index 024551a..24ea98c 100644
--- a/drivers/tty/serial/8250/8250_pci.c
+++ b/drivers/tty/serial/8250/8250_pci.c
@@ -2814,6 +2814,12 @@ void pciserial_suspend_ports(struct serial_private *priv)
 	for (i = 0; i < priv->nr; i++)
 		if (priv->line[i] >= 0)
 			serial8250_suspend_port(priv->line[i]);
+
+	/*
+	 * Ensure that every init quirk is properly torn down
+	 */
+	if (priv->quirk->exit)
+		priv->quirk->exit(priv->dev);
 }
 EXPORT_SYMBOL_GPL(pciserial_suspend_ports);