Fix ALPS touchpad detection

PATCH Superseded Akio Idehara 2 participants 3 messages Feb 15, 2012 – Feb 16, 2012

Subsystems (4)

Documentation HID Input drivers Alps ps/2 touchpad driver

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Akio Idehara

author

2012-02-15 12:58 UTC #0 lore raw

PATCH 1/1 Fix ALPS touchpad detection

ALPS touchpad detection fails if some buttons of ALPS are pressed. The reason is that the query response byte is different from what is expected. This was tested on a Toshiba Portege R500.

Signed-off-by Akio Idehara <[email protected]>

---
 Documentation/input/alps.txt |    3 ++-
 drivers/input/mouse/alps.c   |    5 +++--
 2 files changed, 5 insertions(+), 3 deletions(-)

Documentation/input/alps.txt +2 -1

index f274c28..2f95308 100644
@@ -13,7 +13,8 @@ Detection
 
 All ALPS touchpads should respond to the "E6 report" command sequence:
 E8-E6-E6-E6-E9. An ALPS touchpad should respond with either 00-00-0A or
-00-00-64.
+00-00-64 if no buttons are pressed. The bits 0-2 of the first byte will be 1s
+if some buttons are pressed.
 
 If the E6 report is successful, the touchpad model is identified using the "E7
 report" sequence: E8-E7-E7-E7-E9. The response is the model signature and is

drivers/input/mouse/alps.c +3 -2

index bd87380..d161831 100644
@@ -952,7 +952,8 @@ static const struct alps_model_info *alps_get_model(struct psmouse *psmouse, int
 
 	/*
 	 * First try "E6 report".
-	 * ALPS should return 0,0,10 or 0,0,100
+	 * ALPS should return 0,0,10 or 0,0,100 if no buttons are pressed.
+	 * The bits 0-2 of the first byte will be 1s if some buttons are pressed.
 	 */
 	param[0] = 0;
 	if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES) ||

@@ -968,7 +969,7 @@ static const struct alps_model_info *alps_get_model(struct psmouse *psmouse, int
 	psmouse_dbg(psmouse, "E6 report: %2.2x %2.2x %2.2x",
 		    param[0], param[1], param[2]);
 
-	if (param[0] != 0 || param[1] != 0 || (param[2] != 10 && param[2] != 100))
+	if ((param[0] & 0xf8) != 0 || param[1] != 0 || (param[2] != 10 && param[2] != 100))
 		return NULL;
 
 	/*

Signature · 1 line

1.7.9

Seth Forshee

2012-02-15 16:18 UTC #1 lore raw

Quoted 3 lines · Akio Idehara

ALPS touchpad detection fails if some buttons of ALPS are pressed. The reason is that the query response byte is different from what is expected. This was tested on a Toshiba Portege R500.

I've reproduced the problem and confirmed that your approach fixes it.

However, your patch seems to be malformed as it won't apply cleanly for me. For the comment you're modifying you should also keep the line length under 80 characters.

This fix seems like a good candidate for stable as well.

Seth

Akio Idehara

author

2012-02-16 12:47 UTC #2 lore raw

Thank you for commenting.
I'll send the new one.

Quoted 14 lines · Seth Forshee

Quoted 3 lines · Akio Idehara
ALPS touchpad detection fails if some buttons of ALPS are pressed. The reason is that the query response byte is different from what is expected. This was tested on a Toshiba Portege R500.
I've reproduced the problem and confirmed that your approach fixes it.
However, your patch seems to be malformed as it won't apply cleanly for me. For the comment you're modifying you should also keep the line length under 80 characters.
This fix seems like a good candidate for stable as well.
Seth