Matti, First of all, this is the wrong mailing list for such question.
Nevertheless, here's a response from our kernel team: The wiki that is being referred is obsolete for newer kernels. I have now added a warning saying the page is obsolete. Please follow [1] for v3.14+ kernels. If multiple samples are required in quick successions then it is always better to use continuous mode described in the above wiki. Also, please try patches [2][3] (already in upstream kernel) and see if this helps solve deadlock issue on 3.14. Was this issue reproducible using mainline kernel? [1] http://processors.wiki.ti.com/index.php/Linux_Core_ADC_User%27s_Guide [2] Attached [3] https://patchwork.kernel.org/patch/5582281/ -- Denys On Wed, Jul 08, 2015 at 06:26:58PM +0300, matti kaasinen wrote: > Some more information: distro poky/fido with meta-ti taken from Arago > distribution/fido. Therefore, this kernel driver was coming from > linux-ti-staging_3.14. Board is am2252 based board; very much simplified > am335x-evm. > -Matti > > 2015-07-08 8:56 GMT+03:00 matti kaasinen <[email protected]>: > > > Hi! > > > > I'm experiencing a deadlock while using TI-am335x-adc sysfs interface. It > > appears to happen when I read (i.e. cat) in_voltageX_raw files repeatedly. > > For example, if I execute this with shell script that executes: > > > > while true; do > > for i in 0 1 2 3; do > > cat in_voltage${i}_raw; usleep 250000; > > done;done > > > > I will eventually get lockup for a while and kernel panic with following > > listing: > > ----------- kernel panic listing ----------- > > root@am335x-evm:/sys/devices/ocp/44e0d000.tscadc/TI-am335x-adc/iio:device0# > > cat in_voltage1_raw > > [58197.968353] INFO: task cat:1629 blocked for more than 300 seconds. > > [58197.974615] Not tainted 3.14.46 #1 > > [58197.978628] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables > > this message. > > [58197.986504] cat D c06107d4 0 1629 1618 0x00000000 > > [58197.993021] [<c06107d4>] (__schedule) from [<c03a2008>] > > (am335x_tsc_se_set_once+0xb0/0x100) > > [58198.001491] [<c03a2008>] (am335x_tsc_se_set_once) from [<bf08653c>] > > (tiadc_read_raw+0xb8/0x18c [ti_am335x_adc]) > > [58198.011698] [<bf08653c>] (tiadc_read_raw [ti_am335x_adc]) from > > [<c0504b90>] (iio_read_channel_info+0x34/0x58) > > [58198.021725] [<c0504b90>] (iio_read_channel_info) from [<c03814d8>] > > (dev_attr_show+0x1c/0x48) > > [58198.030260] [<c03814d8>] (dev_attr_show) from [<c0141270>] > > (sysfs_kf_seq_show+0x80/0xf0) > > [58198.038448] [<c0141270>] (sysfs_kf_seq_show) from [<c00ffb1c>] > > (seq_read+0x1f0/0x4a4) > > [58198.046377] [<c00ffb1c>] (seq_read) from [<c00df924>] > > (do_readv_writev+0x1d4/0x214) > > [58198.054124] [<c00df924>] (do_readv_writev) from [<c00df9a4>] > > (vfs_readv+0x40/0x64) > > [58198.061780] [<c00df9a4>] (vfs_readv) from [<c0106e84>] > > (default_file_splice_read+0x204/0x308) > > [58198.070391] [<c0106e84>] (default_file_splice_read) from [<c0105f98>] > > (splice_direct_to_actor+0x8c/0x1d4) > > [58198.080047] [<c0105f98>] (splice_direct_to_actor) from [<c0107390>] > > (do_splice_direct+0x90/0xb8) > > [58198.088919] [<c0107390>] (do_splice_direct) from [<c00df158>] > > (do_sendfile+0x194/0x31c) > > [58198.096979] [<c00df158>] (do_sendfile) from [<c00dfe2c>] > > (SyS_sendfile64+0xd0/0xd4) > > [58198.104727] [<c00dfe2c>] (SyS_sendfile64) from [<c000efe0>] > > (ret_fast_syscall+0x0/0x38) > > [58198.112802] INFO: lockdep is turned off. > > [58198.116753] Kernel panic - not syncing: hung_task: blocked tasks > > [58198.122797] CPU: 0 PID: 498 Comm: khungtaskd Not tainted 3.14.46 #1 > > [58198.129126] [<c0014ce8>] (unwind_backtrace) from [<c001219c>] > > (show_stack+0x10/0x14) > > [58198.136940] [<c001219c>] (show_stack) from [<c060b524>] > > (panic+0x9c/0x1f0) > > [58198.143870] [<c060b524>] (panic) from [<c008fab4>] > > (watchdog+0x3a0/0x3f0) > > [58198.150714] [<c008fab4>] (watchdog) from [<c00537a4>] > > (kthread+0xcc/0xe0) > > [58198.157549] [<c00537a4>] (kthread) from [<c000f080>] > > (ret_from_fork+0x14/0x34) > > [58797.599000] kmemleak: Cannot allocate a kmemleak_object structure > > > > > > Above sequence will give every now and then "cat: read error: Device or > > resource busy" errors, that is clearly listed in > > wiki.tiprocessors.com/.../Processor_SDK_Linux_Kernel_Release_Notes > > <http://wiki.tiprocessors.com/index.php/Processor_SDK_Linux_Kernel_Release_Notes> > > > > However, if I run the same sequence in c program, I will get much more of > > these errors - like every thirth reading will fail. > > > > Third thing to note is that there is no mode (= continuous/single shot) > > node in sysfs > > (/sys/bus/iio/devices/iio:device0/mode) that should be there according to > > http://processors.wiki.ti.com/index.php/AM335x_ADC_Driver%27s_Guide > > > > Thanks, > > Matti > > > _______________________________________________ > meta-arago mailing list > [email protected] > http://arago-project.org/cgi-bin/mailman/listinfo/meta-arago
Subject: [3.14, v4, 2/3] Input: ti_am335x_tsc - remove udelay in interrupt handler (mainline sync) Date: Sat, 13 Jun 2015 00:13:26 -0000 From: Franklin Cooper <[email protected]> X-Patchwork-Id: 14228 TI 3.14 Patch e823ec6f7b5555c65b2b89742fcd705014e8e467 was an early version of mainline patch 344d635b9a41b19837ccf8083a99ea688027019c. Backport the differences between these patches. Signed-off-by: Franklin S Cooper Jr <[email protected]> --- Version 2 and 4 changes: None drivers/input/touchscreen/ti_am335x_tsc.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/drivers/input/touchscreen/ti_am335x_tsc.c b/drivers/input/touchscreen/ti_am335x_tsc.c index 40f1fad..b38e047 100644 --- a/drivers/input/touchscreen/ti_am335x_tsc.c +++ b/drivers/input/touchscreen/ti_am335x_tsc.c @@ -260,7 +260,7 @@ static irqreturn_t titsc_irq(int irq, void *dev) { struct titsc *ts_dev = dev; struct input_dev *input_dev = ts_dev->input; - unsigned int status, irqclr = 0; + unsigned int fsm, status, irqclr = 0; unsigned int x = 0, y = 0; unsigned int z1, z2, z; @@ -271,10 +271,15 @@ static irqreturn_t titsc_irq(int irq, void *dev) } if (status & IRQENB_PENUP) { - ts_dev->pen_down = false; - input_report_key(input_dev, BTN_TOUCH, 0); - input_report_abs(input_dev, ABS_PRESSURE, 0); - input_sync(input_dev); + fsm = titsc_readl(ts_dev, REG_ADCFSM); + if (fsm == ADCFSM_STEPID) { + ts_dev->pen_down = false; + input_report_key(input_dev, BTN_TOUCH, 0); + input_report_abs(input_dev, ABS_PRESSURE, 0); + input_sync(input_dev); + } else { + ts_dev->pen_down = true; + } irqclr |= IRQENB_PENUP; } @@ -313,7 +318,9 @@ static irqreturn_t titsc_irq(int irq, void *dev) } if (irqclr) { titsc_writel(ts_dev, REG_IRQSTATUS, irqclr); - am335x_tsc_se_set_cache(ts_dev->mfd_tscadc, ts_dev->step_mask); + if (status & IRQENB_EOS) + am335x_tsc_se_set_cache(ts_dev->mfd_tscadc, + ts_dev->step_mask); return IRQ_HANDLED; } return IRQ_NONE;
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