* Vignesh R | 2014-11-14 10:37:25 [+0530]:

This series of patches fix TSC defects related to lag in touchscreen
performance and cursor jump at touch release. The lag was result of
udelay in TSC interrupt handler. Cursor jump due to false pen-up event.
The patches implement Advisory 1.0.31 in silicon errata of am335x-evm

am335x not -evm. The am335x-evm is a board (with its own advisory
document) built around the SoC.

Just testing the v4. I can use now IIO and touchscren at the same time.
back at v1 I reported that it does not work, this has been fixed now.
I had it running for a few minutes, now I see one of WARN_ON() beeing
triggered (I've cut a few numbers so don't wonder about PID 2 and so on):

|dmesg |grep WARNING | wc -l
|10
| dmesg |grep WARNING
|[306.257995] WARNING: CPU: 0 PID: 97 at mfd/ti_am335x_tscadc.c:94 am335x_tsc_se_set_once+0xf8/0x104
|[365.469591] WARNING: CPU: 0 PID: 58 at mfd/ti_am335x_tscadc.c:94 am335x_tsc_se_set_once+0xf8/0x104
|[379.255904] WARNING: CPU: 0 PID: 24 at mfd/ti_am335x_tscadc.c:94 am335x_tsc_se_set_once+0xf8/0x104
|[426.230505] WARNING: CPU: 0 PID: 35 at mfd/ti_am335x_tscadc.c:94 am335x_tsc_se_set_once+0xf8/0x104
|[435.654091] WARNING: CPU: 0 PID: 28 at mfd/ti_am335x_tscadc.c:94 am335x_tsc_se_set_once+0xf8/0x104
|[438.897519] WARNING: CPU: 0 PID: 91 at mfd/ti_am335x_tscadc.c:94 am335x_tsc_se_set_once+0xf8/0x104
|[525.720193] WARNING: CPU: 0 PID: 88 at mfd/ti_am335x_tscadc.c:94 am335x_tsc_se_set_once+0xf8/0x104
|[527.644770] WARNING: CPU: 0 PID: 38 at mfd/ti_am335x_tscadc.c:94 am335x_tsc_se_set_once+0xf8/0x104
|[557.218349] WARNING: CPU: 0 PID: 56 at mfd/ti_am335x_tscadc.c:94 am335x_tsc_se_set_once+0xf8/0x104
|[610.077274] WARNING: CPU: 0 PID: 2 at mfd/ti_am335x_tscadc.c:94 am335x_tsc_se_set_once+0xf8/0x104

The complete trace:

|[610.110692] CPU: 0 PID: 4422 Comm: cat Tainted: G        W      3.18.0-rc6+ #1745
|[610.118577] [<c00138ec>] (unwind_backtrace) from [<c0011544>] (show_stack+0x10/0x14)
|[610.126772] [<c0011544>] (show_stack) from [<c003c9b0>] (warn_slowpath_common+0x68/0x88)
|[610.135313] [<c003c9b0>] (warn_slowpath_common) from [<c003c9ec>] (warn_slowpath_null+0x1c/0x24)
|[610.144586] [<c003c9ec>] (warn_slowpath_null) from [<bf00569c>] (am335x_tsc_se_set_once+0xf8/0x104 [ti_am335x_tscadc])
|[610.155886] [<bf00569c>] (am335x_tsc_se_set_once [ti_am335x_tscadc]) from [<bf067494>] (tiadc_read_raw+0xbc/0x190 [ti_am335x_adc])
|[610.168326] [<bf067494>] (tiadc_read_raw [ti_am335x_adc]) from [<bf02dccc>] (iio_read_channel_info+0x9c/0xa4 [industrialio])
|[610.180191] [<bf02dccc>] (iio_read_channel_info [industrialio]) from [<c02a42d4>] (dev_attr_show+0x1c/0x48)
|[610.190477] [<c02a42d4>] (dev_attr_show) from [<c013d544>] (sysfs_kf_seq_show+0x8c/0x110)
|[610.199108] [<c013d544>] (sysfs_kf_seq_show) from [<c013c1c8>] (kernfs_seq_show+0x24/0x28)
|[610.207833] [<c013c1c8>] (kernfs_seq_show) from [<c0102658>] (seq_read+0x1b4/0x47c)
|[610.215922] [<c0102658>] (seq_read) from [<c00e6700>] (vfs_read+0x8c/0x148)
|[610.223269] [<c00e6700>] (vfs_read) from [<c00e67fc>] (SyS_read+0x40/0x8c)
|[610.230525] [<c00e67fc>] (SyS_read) from [<c000e640>] (ret_fast_syscall+0x0/0x30)

Could you please look at that one? (I tested it on am335x-evm btw).

Sebastian