linux-kernel - Re: 2.6.{28,30} Keyboard not working on oldish machine

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Date:	Thu, 3 Sep 2009 22:18:41 -0700
From:	Dmitry Torokhov <dmitry.torokhov@...il.com>
To:	"Dr. David Alan Gilbert" <linux@...blig.org>
Cc:	Jiri Kosina <jkosina@...e.cz>, "H. Peter Anvin" <hpa@...or.com>,
	linux-kernel@...r.kernel.org, linux-input@...r.kernel.org
Subject: Re: 2.6.{28,30} Keyboard not working on oldish machine

On Sun, Jun 28, 2009 at 03:04:52PM +0100, Dr. David Alan Gilbert wrote:
> * Dmitry Torokhov (dmitry.torokhov@...il.com) wrote:
> > On Tuesday 23 June 2009 11:58:15 Dr. David Alan Gilbert wrote:
> 
> <snip>
>  
> > > Yep; I'm OK with the i8042.noaux from my point of view, but it's a
> > > bit worrying that this used to work fine.  There's obviously been
> > > a change somewhere since 2.6.18 (and as I remember from the dmesg
> > > the keyboard and aux ports are being initialised in different orders).
> > > (Actually I say obviously since 2.6.18 - but the 2.6.18 I tried
> > > I think I only used the debian version - I should go back and
> > > see if I can do a vanilla one), but this box has been running
> > > Linux since the time it was originally bought with loads of distros
> > > and clean kernels years ago.
> > >
> > > While this machine is old, the motherboard was a pretty common one
> > > at the time.
> > >
> > 
> > Any chance I could get dmesg with i8042.debug with 2.6.18? There was
> > quite a large change back then when we got rid of the polling timer
> > in i8042.
> 
> Apologies for the delay; attached is the dmesg from the Debian 2.6.18
> in which keyboard works as previously described.
> 

Sorry for taking so long to respond. The only vidible difference beween
the old and the new way is that we don't "close" serio ports anymore if
we fail to detect a mouse/keyboard.

Could you please try the patch below and tell me if it helps?

Thanks!
-- 
Dmitry

Input: i8042 - try disabling and re-enabling AUX port at close

From: Dmitry Torokhov <dmitry.torokhov@...il.com>

Ever since we switched from having a polling timer to registering IRQ
handlers for both keyboard and AUX ports at the driver registration
time, on certain boxes probing for a mouse results in keyboard
stopping working. The only real difference between old and new way is
that before we disabled ports after unsuccessful probe whereas now we
leave them as is. Try to emulate the old behavior by disabling and
immediately re-enabling AUX port when corresponding serio port is
being closed.

Signed-off-by: Dmitry Torokhov <dtor@...l.ru>
---

 drivers/input/serio/i8042.c |   28 ++++++++++++++++++++++++++++
 1 files changed, 28 insertions(+), 0 deletions(-)


diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c
index b53a015..a55ad99 100644
--- a/drivers/input/serio/i8042.c
+++ b/drivers/input/serio/i8042.c
@@ -264,6 +264,33 @@ static int i8042_aux_write(struct serio *serio, unsigned char c)
 					I8042_CMD_MUX_SEND + port->mux);
 }
 
+
+/*
+ * i8042_aux_close attempts to clear AUX port state by disabling
+ * and then re-enabling it.
+ */
+
+static void i8042_aux_close(struct serio *serio)
+{
+	i8042_ctr &= ~I8042_CTR_AUXINT;
+	if (i8042_command(&i8042_ctr, I8042_CMD_CTL_WCTR))
+		printk(KERN_WARNING
+			"i8042.c: Can't write CTR while closing AUX port.\n");
+	udelay(50);
+
+	i8042_ctr &= ~I8042_CTR_AUXDIS;
+	i8042_ctr |= I8042_CTR_AUXINT;
+	if (i8042_command(&i8042_ctr, I8042_CMD_CTL_WCTR))
+		printk(KERN_ERR
+			"i8042.c: Can't reactivate AUX port.\n");
+
+	/*
+	 * See if there is any data appeared while we were messing with
+	 * port state.
+	 */
+	i8042_interrupt(0, NULL);
+}
+
 /*
  * i8042_start() is called by serio core when port is about to finish
  * registering. It will mark port as existing so i8042_interrupt can
@@ -1051,6 +1078,7 @@ static int __devinit i8042_create_aux_port(int idx)
 	serio->write		= i8042_aux_write;
 	serio->start		= i8042_start;
 	serio->stop		= i8042_stop;
+	serio->close		= i8042_aux_close;
 	serio->port_data	= port;
 	serio->dev.parent	= &i8042_platform_device->dev;
 	if (idx < 0) {
--
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