[34-longterm 138/247] mfd: Fix NULL pointer due to non-initialized ucb1x00-ts absinfo

Paul Gortmaker
2011-06-23T18:06:33Z

From: Jochen Friedrich <jochen@scram.de>

-------------------
This is a commit scheduled for the next v2.6.34 longterm release.
If you see a problem with using this for longterm, please comment.
-------------------

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@scram.de>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
drivers/mfd/ucb1x00-ts.c | 12 +++++++++---
1 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/mfd/ucb1x00-ts.c b/drivers/mfd/ucb1x00-ts.c
index 000cb41..92b85e2 100644
--- a/drivers/mfd/ucb1x00-ts.c
+++ b/drivers/mfd/ucb1x00-ts.c
@@ -385,12 +385,18 @@ static int ucb1x00_ts_add(struct ucb1x00_dev *dev)
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;
--
1.7.4.4