On Tue, Feb 1, 2011 at 1:21 AM, Dmitry Torokhov
[off-list ref] wrote:

On Tue, Dec 07, 2010 at 09:12:11PM -0800, Dmitry Torokhov wrote:

quoted

On Mon, Nov 29, 2010 at 01:37:35PM -0800, Duncan Laurie wrote:

quoted

On Sat, Nov 27, 2010 at 12:41 AM, Dmitry Torokhov
[off-list ref] wrote:

quoted

Hi Duncan,

On Mon, Nov 22, 2010 at 03:09:50PM -0800, Duncan Laurie wrote:

quoted

When rebinding a serio driver via sysfs drvctl interface it is possible for
an interrupt to trigger after the disconnect of the existing driver and
before the binding of the new driver.  This will cause the serio interrupt
handler to queue a rescan event which will disconnect the new driver
immediately after it is attached.

This change clears the serio event queue after processing the drvctl
request but before releasing the serio mutex, which will clear any queued
rescans before they can get processed.

Reproduction involves issuing a rebind of device port from psmouse driver
to serio_raw driver while generating input to trigger interrupts.  Then
checking to see if the corresponding i8042/serio4/driver is correctly
attached to the serio_raw driver instead of psmouse.

Signed-off-by: Duncan Laurie <redacted>
---
 drivers/input/serio/serio.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/drivers/input/serio/serio.c b/drivers/input/serio/serio.c
index 405bf21..a66307e 100644
--- a/drivers/input/serio/serio.c
+++ b/drivers/input/serio/serio.c

@@ -454,6 +454,7 @@ static ssize_t serio_rebind_driver(struct device *dev, struct device_attribute *

              serio_disconnect_port(serio);
              error = serio_bind_driver(serio, to_serio_driver(drv));
              put_driver(drv);
+             serio_remove_pending_events(serio);

Hmm, makes sense, although should we limit events being removed to
rescan events only?

That seems reasonable.  It would mean adding a new function or a
parameter to the existing serio_remove_pending_events function, do you
have a preference?

I wonder if a boolean parameter (rescan_only) would not be the best
option.

Hi Duncan,

I eneded up with the following patch, could you please try and see if
it still works for you?

Hi Dmitry,

I tested the patch on a CR-48 device (which is where I was seeing the
problem because we switch to serio_raw at boot for the trackpad) and
it does fix the problem.

Thanks for sending this, it had slipped off my todo list.

-duncan
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