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SubjectRe: [RFC/RFT] Better handling of bad xfers/interrupt delays in psmouse
Date
On Sunday 06 February 2005 00:29, Dmitry Torokhov wrote:
> On Saturday 05 February 2005 16:11, Vojtech Pavlik wrote:
> > On Sat, Feb 05, 2005 at 02:48:56PM -0500, Dmitry Torokhov wrote:
> > > Hi,
> > >
> > > The patch below attempts to better handle situation when psmouse interrupt
> > > is delayed for more than 0.5 sec by requesting a resend. This will allow
> > > properly synchronize with the beginning of the packet as mouse is supposed
> > > to resend entire package.
> >
> > Have you actually tested the mouse is really sending the whole packet?
> > I'd suspect it could just resend the last byte. :I Maybe using the
>
> Well, I did test and my touchpad behaved properly. But then I tried 2 external
> mice and they are both sending ACK (and they should not) and then the last byte
> only. So I guess we'll have to scrap using 0xfe idea...
>
> > GET_PACKET command would be more useful in this case.
> >
>
> Are you talking about 0xeb? We could also try sending "set stream" mode as a
> sync marker...
>

Ok, here is the patch using PSMOUSE_CMD_POLL. Seems to work fine with 2
external mice that I have and my touchpad in PS/2 compatibility mode.

Unfortunately POLL command kicks Synaptics out of absolute mode so I
disabled all time-based sync checks for Synaptics altogether. This should
be OK since Synaptics have pretty strict protocol rules and usually
can resync on their own. I wonder what POLL does to ALPS?

Again, 2.6.10 version can be found here:

http://www.geocities.com/dt_or/input/2_6_10/

Comments/testing is appreciated.

--
Dmitry


===================================================================

ChangeSet@1.2006, 2005-02-06 01:58:47-05:00, dtor_core@ameritech.net
Input: psmouse - better handle bad transfers and interrupt delays
by using POLL command to synchtonize on beginning of a
packet so we don't need to guess whether received byte is
remainder of the last packet or beginning of a new one.

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


psmouse-base.c | 83 +++++++++++++++++++++++++++++++++++++++++++++++++--------
psmouse.h | 1
2 files changed, 73 insertions(+), 11 deletions(-)

===================================================================


diff -Nru a/drivers/input/mouse/psmouse-base.c b/drivers/input/mouse/psmouse-base.c
--- a/drivers/input/mouse/psmouse-base.c 2005-02-06 02:15:18 -05:00
+++ b/drivers/input/mouse/psmouse-base.c 2005-02-06 02:15:18 -05:00
@@ -134,6 +134,49 @@
return PSMOUSE_FULL_PACKET;
}

+static void psmouse_schedule_reconnect(struct psmouse *psmouse)
+{
+ psmouse->state = PSMOUSE_IGNORE;
+ printk(KERN_NOTICE "psmouse.c: issuing reconnect request\n");
+ serio_reconnect(psmouse->ps2dev.serio);
+}
+
+static void psmouse_handle_bad_xfer(struct psmouse *psmouse, unsigned int flags)
+{
+ if (psmouse->state == PSMOUSE_ACTIVATED)
+ printk(KERN_WARNING "psmouse.c: bad data from KBC -%s%s\n",
+ flags & SERIO_TIMEOUT ? " timeout" : "",
+ flags & SERIO_PARITY ? " bad parity" : "");
+
+ if (!psmouse->resend) {
+ /*
+ * This is first error. Try to request resend but not if we
+ * got a timeout and we in initialize phase - there most
+ * likely no mouse at all. Also skip Synaptics as they don't
+ * like POLL command and pass-through ports since we can't
+ * use their serio_write in interrupt context.
+ */
+ if ((psmouse->state > PSMOUSE_INITIALIZING || (~flags & SERIO_TIMEOUT)) &&
+ psmouse->type != PSMOUSE_SYNAPTICS && !psmouse->ps2dev.serio->parent) {
+ if (serio_write(psmouse->ps2dev.serio, PSMOUSE_CMD_POLL & 0xff) == 0) {
+ psmouse->resend = 1;
+ psmouse->pktcnt = 0;
+ }
+ }
+ } else {
+ /*
+ * This is second error in a row. If mouse was itialized - attempt
+ * to rconnect, otherwise just signal failure.
+ */
+ psmouse->resend = 0;
+ if (psmouse->state > PSMOUSE_INITIALIZING)
+ psmouse_schedule_reconnect(psmouse);
+ }
+
+ if (!psmouse->resend)
+ ps2_cmd_aborted(&psmouse->ps2dev);
+}
+
/*
* psmouse_interrupt() handles incoming characters, either gathering them into
* packets or passing them to the command routine as command output.
@@ -149,11 +192,14 @@
goto out;

if (flags & (SERIO_PARITY|SERIO_TIMEOUT)) {
- if (psmouse->state == PSMOUSE_ACTIVATED)
- printk(KERN_WARNING "psmouse.c: bad data from KBC -%s%s\n",
- flags & SERIO_TIMEOUT ? " timeout" : "",
- flags & SERIO_PARITY ? " bad parity" : "");
- ps2_cmd_aborted(&psmouse->ps2dev);
+ psmouse_handle_bad_xfer(psmouse, flags);
+ goto out;
+ }
+
+ if (unlikely(psmouse->resend)) {
+ psmouse->resend = 0;
+ if (data != PSMOUSE_RET_ACK)
+ psmouse_schedule_reconnect(psmouse);
goto out;
}

@@ -168,11 +214,28 @@
if (psmouse->state == PSMOUSE_INITIALIZING)
goto out;

+ /*
+ * If there is a long delay between bytes in a packet we suspect
+ * that we lost synchronization and will try to restore it by
+ * requesting transmission of a full packet from th? mouse.
+ * Unfortunately POLL command kicks Synaptics touchpads out of
+ * absolute mode, so we skip them (but they have good protocol
+ * checks and usually can re-sync without problems). We also don't
+ * try to re-sync devices on pass-through ports as their serio_write
+ * can't be used in interrupt context and they usually in sync as
+ * long as their parent is.
+ */
if (psmouse->state == PSMOUSE_ACTIVATED &&
+ psmouse->type != PSMOUSE_SYNAPTICS &&
+ !serio->parent &&
psmouse->pktcnt && time_after(jiffies, psmouse->last + HZ/2)) {
printk(KERN_WARNING "psmouse.c: %s at %s lost synchronization, throwing %d bytes away.\n",
psmouse->name, psmouse->phys, psmouse->pktcnt);
psmouse->pktcnt = 0;
+ if (serio_write(serio, PSMOUSE_CMD_POLL & 0xff) == 0) {
+ psmouse->resend = 1;
+ goto out;
+ }
}

psmouse->last = jiffies;
@@ -206,11 +269,9 @@
psmouse->name, psmouse->phys, psmouse->pktcnt);
psmouse->pktcnt = 0;

- if (++psmouse->out_of_sync == psmouse->resetafter) {
- psmouse->state = PSMOUSE_IGNORE;
- printk(KERN_NOTICE "psmouse.c: issuing reconnect request\n");
- serio_reconnect(psmouse->ps2dev.serio);
- }
+ if (++psmouse->out_of_sync == psmouse->resetafter)
+ psmouse_schedule_reconnect(psmouse);
+
break;

case PSMOUSE_FULL_PACKET:
@@ -594,7 +655,7 @@
{
serio_pause_rx(psmouse->ps2dev.serio);
psmouse->state = new_state;
- psmouse->pktcnt = psmouse->out_of_sync = 0;
+ psmouse->pktcnt = psmouse->out_of_sync = psmouse->resend = 0;
psmouse->ps2dev.flags = 0;
serio_continue_rx(psmouse->ps2dev.serio);
}
diff -Nru a/drivers/input/mouse/psmouse.h b/drivers/input/mouse/psmouse.h
--- a/drivers/input/mouse/psmouse.h 2005-02-06 02:15:18 -05:00
+++ b/drivers/input/mouse/psmouse.h 2005-02-06 02:15:18 -05:00
@@ -48,6 +48,7 @@
unsigned long last;
unsigned long out_of_sync;
enum psmouse_state state;
+ unsigned int resend;
char devname[64];
char phys[32];

-
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