[PATCH] [161/275] mfd: Fix NULL pointer due to non-initialized ucb1x00-ts absinfo

[Andi Kleen]

2.6.35-longterm review patch.  If anyone has any objections, please let me know.

------------------
From: Jochen Friedrich <jochen@xxxxxxxx>

commit 9063f1f15eec35e5fd608879cef8be5728f2d12a upstream.

Call input_set_abs_params instead of manually setting absbit only.
This fixes this oops:

Unable to handle kernel NULL pointer dereference at virtual address 00000024
Internal error: Oops: 41b67017 [#1]
CPU: 0    Not tainted  (2.6.37 #4)
pc : [<c016d1fc>]    lr : [<00000000>]    psr: 20000093
sp : c19e5f30  ip : c19e5e6c  fp : c19e5f58
r10: 00000000  r9 : c19e4000  r8 : 00000003
r7 : 000001e4  r6 : 00000001  r5 : c1854400  r4 : 00000003
r3 : 00000018  r2 : 00000018  r1 : 00000018  r0 : c185447c
Flags: nzCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
Control: c1b6717f  Table: c1b6717f  DAC: 00000017
Stack: (0xc19e5f30 to 0xc19e6000)
5f20:                                     00000003 00000003 c1854400 00000013
5f40: 00000001 000001e4 000001c5 c19e5f80 c19e5f5c c016d5e8 c016cf5c 000001e4
5f60: c1854400 c18b5860 00000000 00000171 000001e4 c19e5fc4 c19e5f84 c01559a4
5f80: c016d584 c18b5868 00000000 c1bb5c40 c0035afc c18b5868 c18b5868 c1a55d54
5fa0: c18b5860 c0155750 00000013 00000000 00000000 00000000 c19e5ff4 c19e5fc8
5fc0: c0050174 c015575c 00000000 c18b5860 00000000 c19e5fd4 c19e5fd4 c1a55d54
5fe0: c00500f0 c003b464 00000000 c19e5ff8 c003b464 c00500fc 04000400 04000400
Backtrace:
Function entered at [<c016cf50>] from [<c016d5e8>]
Function entered at [<c016d578>] from [<c01559a4>]
 r8:000001e4 r7:00000171 r6:00000000 r5:c18b5860 r4:c1854400
Function entered at [<c0155750>] from [<c0050174>]
Function entered at [<c00500f0>] from [<c003b464>]
 r6:c003b464 r5:c00500f0 r4:c1a55d54
Code: e59520fc e1a03286 e0433186 e0822003 (e592000c)

>>PC;  c016d1fc <input_handle_event+2ac/5a0>   <=====

Trace; c016cf50 <input_handle_event+0/5a0>
Trace; c016d5e8 <input_event+70/88>
Trace; c016d578 <input_event+0/88>
Trace; c01559a4 <ucb1x00_thread+254/2dc>
Trace; c0155750 <ucb1x00_thread+0/2dc>
Trace; c0050174 <kthread+84/8c>
Trace; c00500f0 <kthread+0/8c>
Trace; c003b464 <do_exit+0/624>

Signed-off-by: Jochen Friedrich <jochen@xxxxxxxx>
Signed-off-by: Samuel Ortiz <sameo@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>

---
 drivers/mfd/ucb1x00-ts.c |   12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

Index: linux-2.6.35.y/drivers/mfd/ucb1x00-ts.c
===================================================================
--- linux-2.6.35.y.orig/drivers/mfd/ucb1x00-ts.c	2011-03-29 22:51:00.879700658 -0700
+++ linux-2.6.35.y/drivers/mfd/ucb1x00-ts.c	2011-03-29 23:03:01.604259121 -0700
@@ -385,12 +385,18 @@
 	idev->close      = ucb1x00_ts_close;
 
 	__set_bit(EV_ABS, idev->evbit);
-	__set_bit(ABS_X, idev->absbit);
-	__set_bit(ABS_Y, idev->absbit);
-	__set_bit(ABS_PRESSURE, idev->absbit);
 
 	input_set_drvdata(idev, ts);
 
+	ucb1x00_adc_enable(ts->ucb);
+	ts->x_res = ucb1x00_ts_read_xres(ts);
+	ts->y_res = ucb1x00_ts_read_yres(ts);
+	ucb1x00_adc_disable(ts->ucb);
+
+	input_set_abs_params(idev, ABS_X, 0, ts->x_res, 0, 0);
+	input_set_abs_params(idev, ABS_Y, 0, ts->y_res, 0, 0);
+	input_set_abs_params(idev, ABS_PRESSURE, 0, 0, 0, 0);
+
 	err = input_register_device(idev);
 	if (err)
 		goto fail;
--
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