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author | Roland Scheidegger <sroland@tungstengraphics.com> | 2007-05-24 09:37:31 -0400 |
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committer | Chris Wright <chrisw@sous-sol.org> | 2007-06-11 11:36:46 -0700 |
commit | 6f27f35162b8bcdcc598b49449b2801fa80084c7 (patch) | |
tree | 7025d35c23ff8f62a7ac8949923d3cf92dd4093e | |
parent | 4bf8ff91b6120271f60055526c30a9ae8b93b3c7 (diff) | |
download | lwn-6f27f35162b8bcdcc598b49449b2801fa80084c7.tar.gz lwn-6f27f35162b8bcdcc598b49449b2801fa80084c7.zip |
[PATCH] Input: i8042 - fix AUX port detection with some chips
The i8042 driver fails detection of the AUX port with some chips,
because they apparently do not change the I8042_CTR_AUXDIS bit
immediately. This is known to affect at least HP500/HP510 notebooks,
consequently the built-in touchpad will not work. The patch will simply
reread the value until it gets the expected value or a retry limit is
hit, without touching other workaround code in the same area.
Signed-off-by: Roland Scheidegger <sroland@tungstengraphics.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r-- | drivers/input/serio/i8042.c | 35 |
1 files changed, 29 insertions, 6 deletions
diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c index db9cca3b65e0..23411aba1fb0 100644 --- a/drivers/input/serio/i8042.c +++ b/drivers/input/serio/i8042.c @@ -526,6 +526,33 @@ static irqreturn_t __devinit i8042_aux_test_irq(int irq, void *dev_id) return IRQ_HANDLED; } +/* + * i8042_toggle_aux - enables or disables AUX port on i8042 via command and + * verifies success by readinng CTR. Used when testing for presence of AUX + * port. + */ +static int __devinit i8042_toggle_aux(int on) +{ + unsigned char param; + int i; + + if (i8042_command(¶m, + on ? I8042_CMD_AUX_ENABLE : I8042_CMD_AUX_DISABLE)) + return -1; + + /* some chips need some time to set the I8042_CTR_AUXDIS bit */ + for (i = 0; i < 100; i++) { + udelay(50); + + if (i8042_command(¶m, I8042_CMD_CTL_RCTR)) + return -1; + + if (!(param & I8042_CTR_AUXDIS) == on) + return 0; + } + + return -1; +} /* * i8042_check_aux() applies as much paranoia as it can at detecting @@ -580,16 +607,12 @@ static int __devinit i8042_check_aux(void) * Bit assignment test - filters out PS/2 i8042's in AT mode */ - if (i8042_command(¶m, I8042_CMD_AUX_DISABLE)) - return -1; - if (i8042_command(¶m, I8042_CMD_CTL_RCTR) || (~param & I8042_CTR_AUXDIS)) { + if (i8042_toggle_aux(0)) { printk(KERN_WARNING "Failed to disable AUX port, but continuing anyway... Is this a SiS?\n"); printk(KERN_WARNING "If AUX port is really absent please use the 'i8042.noaux' option.\n"); } - if (i8042_command(¶m, I8042_CMD_AUX_ENABLE)) - return -1; - if (i8042_command(¶m, I8042_CMD_CTL_RCTR) || (param & I8042_CTR_AUXDIS)) + if (i8042_toggle_aux(1)) return -1; /* |