Hi!
Hmm. Looks like there's a lot of fun to be had with sysfs.
Pavel
pavel@n900:~$ uname -a
Linux n900 4.16.0-rc4-59690-g7f84626-dirty #543 Thu Mar 8 19:53:30 CET
2018 armv7l GNU/Linux
[ 306.402496] bq2415x: command Timer reset
[ 312.761322] adp1653 2-0030: Read Addr:03 Val:00 ok
[ 313.264129] Unable to handle kernel NULL pointer dereference at
virtual address 00000
000
[ 313.272308] pgd = 01336620
[ 313.275146] [00000000] *pgd=800af831, *pte=00000000, *ppte=00000000
[ 313.281463] Internal error: Oops: 80000007 [#1] ARM
[ 313.286376] Modules linked in:
[ 313.289459] CPU: 0 PID: 3584 Comm: grep Tainted: G W
4.16.0-rc4-59690-g
7f84626-dirty #543
[ 313.298919] Hardware name: Nokia RX-51 board
[ 313.303222] PC is at (null)
[ 313.306213] LR is at iio_ev_state_show+0x38/0x54
[ 313.310852] pc : [<00000000>] lr : [<c05d69c0>] psr: a0000013
[ 313.317169] sp : c7b47e70 ip : c087bb24 fp : 00000001
[ 313.322418] r10: cb19e000 r9 : c0857220 r8 : 00001000
[ 313.327667] r7 : 00000fff r6 : cb711c80 r5 : cb19e000 r4 :
00000000
[ 313.334228] r3 : 00000001 r2 : 00000000 r1 : c087b4dc r0 :
ce584800
[ 313.340789] Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM
Segment none
[ 313.347991] Control: 10c5387d Table: 87bec019 DAC: 00000051
[ 313.353759] Process grep (pid: 3584, stack limit = 0xc4e45eab)
[ 313.359619] Stack: (0xc7b47e70 to 0xc7b48000)
[ 313.364013] 7e60: c05d6988
cb711b00 ce585c00 c0450d68
[ 313.471038] [<c05d69c0>] (iio_ev_state_show) from [<c0450d68>]
(dev_attr_show+0x1c/0x4c)
[ 313.479187] [<c0450d68>] (dev_attr_show) from [<c023f934>]
(sysfs_kf_seq_show+0x90/0x108)
[ 313.487426] [<c023f934>] (sysfs_kf_seq_show) from [<c023e2f8>]
(kernfs_seq_show+0x24/0x28)
[ 313.495758] [<c023e2f8>] (kernfs_seq_show) from [<c01fc954>]
(seq_read+0x1dc/0x500)
[ 313.503479] [<c01fc954>] (seq_read) from [<c01d9f80>]
(__vfs_read+0x2c/0x120)
[ 313.510681] [<c01d9f80>] (__vfs_read) from [<c01da0fc>]
(vfs_read+0x88/0x114)
[ 313.517852] [<c01da0fc>] (vfs_read) from [<c01da584>]
(SyS_read+0x40/0x8c)
[ 313.524780] [<c01da584>] (SyS_read) from [<c0101000>]
(ret_fast_syscall+0x0/0x54)
[ 313.532318] Exception stack(0xc7b47fa8 to 0xc7b47ff0)
[ 313.537414] 7fa0: 00035330 00042000 00000003
00042000 00008000 00008000
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
On Fri, Mar 09, 2018 at 11:12:21PM +0100, Pavel Machek wrote:
> Hi!
>
> Hmm. Looks like there's a lot of fun to be had with sysfs.
>
> Pavel
>
>
> pavel@n900:~$ uname -a
> Linux n900 4.16.0-rc4-59690-g7f84626-dirty #543 Thu Mar 8 19:53:30 CET
> 2018 armv7l GNU/Linux
>
> [ 306.402496] bq2415x: command Timer reset
> [ 312.761322] adp1653 2-0030: Read Addr:03 Val:00 ok
> [ 313.264129] Unable to handle kernel NULL pointer dereference at
> virtual address 00000
> 000
> [ 313.272308] pgd = 01336620
> [ 313.275146] [00000000] *pgd=800af831, *pte=00000000, *ppte=00000000
> [ 313.281463] Internal error: Oops: 80000007 [#1] ARM
> [ 313.286376] Modules linked in:
> [ 313.289459] CPU: 0 PID: 3584 Comm: grep Tainted: G W
> 4.16.0-rc4-59690-g
> 7f84626-dirty #543
> [ 313.298919] Hardware name: Nokia RX-51 board
> [ 313.303222] PC is at (null)
> [ 313.306213] LR is at iio_ev_state_show+0x38/0x54
> [ 313.310852] pc : [<00000000>] lr : [<c05d69c0>] psr: a0000013
> [ 313.317169] sp : c7b47e70 ip : c087bb24 fp : 00000001
> [ 313.322418] r10: cb19e000 r9 : c0857220 r8 : 00001000
> [ 313.327667] r7 : 00000fff r6 : cb711c80 r5 : cb19e000 r4 :
> 00000000
> [ 313.334228] r3 : 00000001 r2 : 00000000 r1 : c087b4dc r0 :
> ce584800
> [ 313.340789] Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM
> Segment none
> [ 313.347991] Control: 10c5387d Table: 87bec019 DAC: 00000051
> [ 313.353759] Process grep (pid: 3584, stack limit = 0xc4e45eab)
> [ 313.359619] Stack: (0xc7b47e70 to 0xc7b48000)
> [ 313.364013] 7e60: c05d6988
> cb711b00 ce585c00 c0450d68
> [ 313.471038] [<c05d69c0>] (iio_ev_state_show) from [<c0450d68>]
> (dev_attr_show+0x1c/0x4c)
> [ 313.479187] [<c0450d68>] (dev_attr_show) from [<c023f934>]
> (sysfs_kf_seq_show+0x90/0x108)
> [ 313.487426] [<c023f934>] (sysfs_kf_seq_show) from [<c023e2f8>]
> (kernfs_seq_show+0x24/0x28)
> [ 313.495758] [<c023e2f8>] (kernfs_seq_show) from [<c01fc954>]
> (seq_read+0x1dc/0x500)
> [ 313.503479] [<c01fc954>] (seq_read) from [<c01d9f80>]
> (__vfs_read+0x2c/0x120)
> [ 313.510681] [<c01d9f80>] (__vfs_read) from [<c01da0fc>]
> (vfs_read+0x88/0x114)
> [ 313.517852] [<c01da0fc>] (vfs_read) from [<c01da584>]
> (SyS_read+0x40/0x8c)
> [ 313.524780] [<c01da584>] (SyS_read) from [<c0101000>]
> (ret_fast_syscall+0x0/0x54)
> [ 313.532318] Exception stack(0xc7b47fa8 to 0xc7b47ff0)
> [ 313.537414] 7fa0: 00035330 00042000 00000003
> 00042000 00008000 00008000
>
What file are you opening to cause this?
thanks,
greg k-h
Hi!
> > Hmm. Looks like there's a lot of fun to be had with sysfs.
> >
> >
> > pavel@n900:~$ uname -a
> > Linux n900 4.16.0-rc4-59690-g7f84626-dirty #543 Thu Mar 8 19:53:30 CET
> > 2018 armv7l GNU/Linux
> >
> > [ 306.402496] bq2415x: command Timer reset
> > [ 312.761322] adp1653 2-0030: Read Addr:03 Val:00 ok
> > [ 313.264129] Unable to handle kernel NULL pointer dereference at
> > virtual address 00000
> > 000
> > [ 313.272308] pgd = 01336620
> > [ 313.275146] [00000000] *pgd=800af831, *pte=00000000, *ppte=00000000
> > [ 313.281463] Internal error: Oops: 80000007 [#1] ARM
> > [ 313.286376] Modules linked in:
> > [ 313.289459] CPU: 0 PID: 3584 Comm: grep Tainted: G W
> > 4.16.0-rc4-59690-g
> > 7f84626-dirty #543
> > [ 313.298919] Hardware name: Nokia RX-51 board
> > [ 313.303222] PC is at (null)
> > [ 313.306213] LR is at iio_ev_state_show+0x38/0x54
> > [ 313.310852] pc : [<00000000>] lr : [<c05d69c0>] psr: a0000013
> > [ 313.317169] sp : c7b47e70 ip : c087bb24 fp : 00000001
> > [ 313.322418] r10: cb19e000 r9 : c0857220 r8 : 00001000
> > [ 313.327667] r7 : 00000fff r6 : cb711c80 r5 : cb19e000 r4 :
> > 00000000
> > [ 313.334228] r3 : 00000001 r2 : 00000000 r1 : c087b4dc r0 :
> > ce584800
> > [ 313.340789] Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM
> > Segment none
> > [ 313.347991] Control: 10c5387d Table: 87bec019 DAC: 00000051
> > [ 313.353759] Process grep (pid: 3584, stack limit = 0xc4e45eab)
> > [ 313.359619] Stack: (0xc7b47e70 to 0xc7b48000)
> > [ 313.364013] 7e60: c05d6988
> > cb711b00 ce585c00 c0450d68
> > [ 313.471038] [<c05d69c0>] (iio_ev_state_show) from [<c0450d68>]
> > (dev_attr_show+0x1c/0x4c)
> > [ 313.479187] [<c0450d68>] (dev_attr_show) from [<c023f934>]
> > (sysfs_kf_seq_show+0x90/0x108)
> > [ 313.487426] [<c023f934>] (sysfs_kf_seq_show) from [<c023e2f8>]
> > (kernfs_seq_show+0x24/0x28)
> > [ 313.495758] [<c023e2f8>] (kernfs_seq_show) from [<c01fc954>]
> > (seq_read+0x1dc/0x500)
> > [ 313.503479] [<c01fc954>] (seq_read) from [<c01d9f80>]
> > (__vfs_read+0x2c/0x120)
> > [ 313.510681] [<c01d9f80>] (__vfs_read) from [<c01da0fc>]
> > (vfs_read+0x88/0x114)
> > [ 313.517852] [<c01da0fc>] (vfs_read) from [<c01da584>]
> > (SyS_read+0x40/0x8c)
> > [ 313.524780] [<c01da584>] (SyS_read) from [<c0101000>]
> > (ret_fast_syscall+0x0/0x54)
> > [ 313.532318] Exception stack(0xc7b47fa8 to 0xc7b47ff0)
> > [ 313.537414] 7fa0: 00035330 00042000 00000003
> > 00042000 00008000 00008000
> >
>
> What file are you opening to cause this?
Strace says:
openat(7, "in_intensity_both_thresh_rising_en",
> > O_RDONLY|O_LARGEFILE|O_NOFOLLOW) = 3
fstat64(3, {st_mode=S_IFREG|0644, st_size=4096, ...}) = 0
ioctl(3, SNDCTL_TMR_TIMEBASE or TCGETS, 0xbe83b714) = -1 ENOTTY
> > (Inappropriate ioctl for device)
read(3,
Message from syslogd@localhost at Mar 9 23:54:39 ...
kernel:[ 3097.357696] Internal error: Oops: 80000007 [#2] ARM
So that would be:
./devices/platform/68000000.ocp/48072000.i2c/i2c-2/2-0029/iio:device1/events/in_intensity_both_thresh_rising_en
And indeed, manually cat-ing that file reproduces the problem.
pavel@n900:/sys/devices/platform/68000000.ocp/48072000.i2c/i2c-2/2-0029/iio:device1$
cat name
tsl2563
I can not find tsl2563 in MAINTAINERS, file is
./drivers/iio/light/tsl2563.c . I added few people pointed by git log.
Best regards,
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
On 03/10/2018 12:01 AM, Pavel Machek wrote:
[...]
>> What file are you opening to cause this?
>
> Strace says:
>
> openat(7, "in_intensity_both_thresh_rising_en",
>>> O_RDONLY|O_LARGEFILE|O_NOFOLLOW) = 3
> fstat64(3, {st_mode=S_IFREG|0644, st_size=4096, ...}) = 0
> ioctl(3, SNDCTL_TMR_TIMEBASE or TCGETS, 0xbe83b714) = -1 ENOTTY
>>> (Inappropriate ioctl for device)
> read(3,
> Message from syslogd@localhost at Mar 9 23:54:39 ...
> kernel:[ 3097.357696] Internal error: Oops: 80000007 [#2] ARM
>
> So that would be:
>
> ./devices/platform/68000000.ocp/48072000.i2c/i2c-2/2-0029/iio:device1/events/in_intensity_both_thresh_rising_en
>
> And indeed, manually cat-ing that file reproduces the problem.
>
> pavel@n900:/sys/devices/platform/68000000.ocp/48072000.i2c/i2c-2/2-0029/iio:device1$
> cat name
> tsl2563
>
> I can not find tsl2563 in MAINTAINERS, file is
> ./drivers/iio/light/tsl2563.c . I added few people pointed by git log.
The driver registers event attributes, but does not provide a handle to
access those attributes.
Now the question is how to best handle this case.
1) Return an error when the device is registered and abort registration
2) Skip registering the event attributes
3) Skip registering the event attributes, but print a warning
4) Register the attributes, but return an error when they are accessed
I'd prefer 2 since it offers a nice method of disabling all events for a
device (e.g. if not interrupt is provided).
On the other hand it could cause some confusion during development,
potentially causing the developer to wonder why he doesn't get any event
attributes even though he setup his channel description to have event
attributes.
Patch for 2.
--- a/drivers/iio/industrialio-event.c
+++ b/drivers/iio/industrialio-event.c
@@ -477,7 +477,8 @@ int iio_device_register_eventset(struct iio_dev
struct attribute **attr;
if (!(indio_dev->info->event_attrs ||
- iio_check_for_dynamic_events(indio_dev)))
+ iio_check_for_dynamic_events(indio_dev)) ||
+ !indio_dev->info->read_event_config)
return 0;
indio_dev->event_interface =
2018-03-10 8:01 GMT+09:00 Pavel Machek <[email protected]>:
> Hi!
>
>> > Hmm. Looks like there's a lot of fun to be had with sysfs.
>> >
>> >
>> > pavel@n900:~$ uname -a
>> > Linux n900 4.16.0-rc4-59690-g7f84626-dirty #543 Thu Mar 8 19:53:30 CET
>> > 2018 armv7l GNU/Linux
>> >
>> > [ 306.402496] bq2415x: command Timer reset
>> > [ 312.761322] adp1653 2-0030: Read Addr:03 Val:00 ok
>> > [ 313.264129] Unable to handle kernel NULL pointer dereference at
>> > virtual address 00000
>> > 000
>> > [ 313.272308] pgd = 01336620
>> > [ 313.275146] [00000000] *pgd=800af831, *pte=00000000, *ppte=00000000
>> > [ 313.281463] Internal error: Oops: 80000007 [#1] ARM
>> > [ 313.286376] Modules linked in:
>> > [ 313.289459] CPU: 0 PID: 3584 Comm: grep Tainted: G W
>> > 4.16.0-rc4-59690-g
>> > 7f84626-dirty #543
>> > [ 313.298919] Hardware name: Nokia RX-51 board
>> > [ 313.303222] PC is at (null)
>> > [ 313.306213] LR is at iio_ev_state_show+0x38/0x54
>> > [ 313.310852] pc : [<00000000>] lr : [<c05d69c0>] psr: a0000013
>> > [ 313.317169] sp : c7b47e70 ip : c087bb24 fp : 00000001
>> > [ 313.322418] r10: cb19e000 r9 : c0857220 r8 : 00001000
>> > [ 313.327667] r7 : 00000fff r6 : cb711c80 r5 : cb19e000 r4 :
>> > 00000000
>> > [ 313.334228] r3 : 00000001 r2 : 00000000 r1 : c087b4dc r0 :
>> > ce584800
>> > [ 313.340789] Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM
>> > Segment none
>> > [ 313.347991] Control: 10c5387d Table: 87bec019 DAC: 00000051
>> > [ 313.353759] Process grep (pid: 3584, stack limit = 0xc4e45eab)
>> > [ 313.359619] Stack: (0xc7b47e70 to 0xc7b48000)
>> > [ 313.364013] 7e60: c05d6988
>> > cb711b00 ce585c00 c0450d68
>> > [ 313.471038] [<c05d69c0>] (iio_ev_state_show) from [<c0450d68>]
>> > (dev_attr_show+0x1c/0x4c)
>> > [ 313.479187] [<c0450d68>] (dev_attr_show) from [<c023f934>]
>> > (sysfs_kf_seq_show+0x90/0x108)
>> > [ 313.487426] [<c023f934>] (sysfs_kf_seq_show) from [<c023e2f8>]
>> > (kernfs_seq_show+0x24/0x28)
>> > [ 313.495758] [<c023e2f8>] (kernfs_seq_show) from [<c01fc954>]
>> > (seq_read+0x1dc/0x500)
>> > [ 313.503479] [<c01fc954>] (seq_read) from [<c01d9f80>]
>> > (__vfs_read+0x2c/0x120)
>> > [ 313.510681] [<c01d9f80>] (__vfs_read) from [<c01da0fc>]
>> > (vfs_read+0x88/0x114)
>> > [ 313.517852] [<c01da0fc>] (vfs_read) from [<c01da584>]
>> > (SyS_read+0x40/0x8c)
>> > [ 313.524780] [<c01da584>] (SyS_read) from [<c0101000>]
>> > (ret_fast_syscall+0x0/0x54)
>> > [ 313.532318] Exception stack(0xc7b47fa8 to 0xc7b47ff0)
>> > [ 313.537414] 7fa0: 00035330 00042000 00000003
>> > 00042000 00008000 00008000
>> >
>>
>> What file are you opening to cause this?
>
> Strace says:
>
> openat(7, "in_intensity_both_thresh_rising_en",
>> > O_RDONLY|O_LARGEFILE|O_NOFOLLOW) = 3
> fstat64(3, {st_mode=S_IFREG|0644, st_size=4096, ...}) = 0
> ioctl(3, SNDCTL_TMR_TIMEBASE or TCGETS, 0xbe83b714) = -1 ENOTTY
>> > (Inappropriate ioctl for device)
> read(3,
> Message from syslogd@localhost at Mar 9 23:54:39 ...
> kernel:[ 3097.357696] Internal error: Oops: 80000007 [#2] ARM
>
> So that would be:
>
> ./devices/platform/68000000.ocp/48072000.i2c/i2c-2/2-0029/iio:device1/events/in_intensity_both_thresh_rising_en
>
> And indeed, manually cat-ing that file reproduces the problem.
This problem happens when no irq is defined for this device.
In this case, tsl2563_info_no_irq whose read_event_config field is NULL
is selected as iio_info. On the other hand, iio_chan_spec for this
driver always registers event_spec.
So sysfs files related to the channel events are always created even if
no irq is defined.
I think we can fix this issue by defining another iio_chan_spec with
no event_spec for no irq case.
Jonathan, do you have any other idea how to fix this issue?
Hi!
On Sat 2018-03-10 12:19:29, Lars-Peter Clausen wrote:
> On 03/10/2018 12:01 AM, Pavel Machek wrote:
> [...]
> >> What file are you opening to cause this?
> >
> > Strace says:
> >
> > openat(7, "in_intensity_both_thresh_rising_en",
> >>> O_RDONLY|O_LARGEFILE|O_NOFOLLOW) = 3
> > fstat64(3, {st_mode=S_IFREG|0644, st_size=4096, ...}) = 0
> > ioctl(3, SNDCTL_TMR_TIMEBASE or TCGETS, 0xbe83b714) = -1 ENOTTY
> >>> (Inappropriate ioctl for device)
> > read(3,
> > Message from syslogd@localhost at Mar 9 23:54:39 ...
> > kernel:[ 3097.357696] Internal error: Oops: 80000007 [#2] ARM
> >
> > So that would be:
> >
> > ./devices/platform/68000000.ocp/48072000.i2c/i2c-2/2-0029/iio:device1/events/in_intensity_both_thresh_rising_en
> >
> > And indeed, manually cat-ing that file reproduces the problem.
> >
> > pavel@n900:/sys/devices/platform/68000000.ocp/48072000.i2c/i2c-2/2-0029/iio:device1$
> > cat name
> > tsl2563
> >
> > I can not find tsl2563 in MAINTAINERS, file is
> > ./drivers/iio/light/tsl2563.c . I added few people pointed by git log.
>
> The driver registers event attributes, but does not provide a handle to
> access those attributes.
>
> Now the question is how to best handle this case.
>
> 1) Return an error when the device is registered and abort registration
> 2) Skip registering the event attributes
> 3) Skip registering the event attributes, but print a warning
> 4) Register the attributes, but return an error when they are accessed
>
> I'd prefer 2 since it offers a nice method of disabling all events for a
> device (e.g. if not interrupt is provided).
2 works for me.
Tested-by: Pavel Machek <[email protected]>
Reported-by: Pavel Machek <[email protected]>
Now grep -ri asdfasdf /sys finishes.
Thanks,
Pavel
> --- a/drivers/iio/industrialio-event.c
> +++ b/drivers/iio/industrialio-event.c
> @@ -477,7 +477,8 @@ int iio_device_register_eventset(struct iio_dev
> struct attribute **attr;
>
> if (!(indio_dev->info->event_attrs ||
> - iio_check_for_dynamic_events(indio_dev)))
> + iio_check_for_dynamic_events(indio_dev)) ||
> + !indio_dev->info->read_event_config)
> return 0;
>
> indio_dev->event_interface =
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
On Sat, 10 Mar 2018 13:00:53 +0100
Pavel Machek <[email protected]> wrote:
> Hi!
>
> On Sat 2018-03-10 12:19:29, Lars-Peter Clausen wrote:
> > On 03/10/2018 12:01 AM, Pavel Machek wrote:
> > [...]
> > >> What file are you opening to cause this?
> > >
> > > Strace says:
> > >
> > > openat(7, "in_intensity_both_thresh_rising_en",
> > >>> O_RDONLY|O_LARGEFILE|O_NOFOLLOW) = 3
> > > fstat64(3, {st_mode=S_IFREG|0644, st_size=4096, ...}) = 0
> > > ioctl(3, SNDCTL_TMR_TIMEBASE or TCGETS, 0xbe83b714) = -1 ENOTTY
> > >>> (Inappropriate ioctl for device)
> > > read(3,
> > > Message from syslogd@localhost at Mar 9 23:54:39 ...
> > > kernel:[ 3097.357696] Internal error: Oops: 80000007 [#2] ARM
> > >
> > > So that would be:
> > >
> > > ./devices/platform/68000000.ocp/48072000.i2c/i2c-2/2-0029/iio:device1/events/in_intensity_both_thresh_rising_en
> > >
> > > And indeed, manually cat-ing that file reproduces the problem.
> > >
> > > pavel@n900:/sys/devices/platform/68000000.ocp/48072000.i2c/i2c-2/2-0029/iio:device1$
> > > cat name
> > > tsl2563
> > >
> > > I can not find tsl2563 in MAINTAINERS, file is
> > > ./drivers/iio/light/tsl2563.c . I added few people pointed by git log.
> >
> > The driver registers event attributes, but does not provide a handle to
> > access those attributes.
> >
> > Now the question is how to best handle this case.
> >
> > 1) Return an error when the device is registered and abort registration
> > 2) Skip registering the event attributes
> > 3) Skip registering the event attributes, but print a warning
> > 4) Register the attributes, but return an error when they are accessed
> >
> > I'd prefer 2 since it offers a nice method of disabling all events for a
> > device (e.g. if not interrupt is provided).
>
> 2 works for me.
>
> Tested-by: Pavel Machek <[email protected]>
> Reported-by: Pavel Machek <[email protected]>
>
> Now grep -ri asdfasdf /sys finishes.
Hmm. I'd count this as a good general prevention of what is actually
a driver bug. The driver should either have failed or as has been suggested
should have come up without the event sysfs attributes by registering different
abilities.
So I'm favour of this change, but from a semantic point of view I'd
like the addition of a warning for this case and ideally for the driver
to be fixed to not attempt to add them (two iio_info structures which
is what a lot of other drivers do to allow them to work with and
without the interrupt being available.).
Anyhow, Lars, please send a formal patch for the below and we'll
get that headed for mainline asap.
>
> Thanks,
> Pavel
>
> > --- a/drivers/iio/industrialio-event.c
> > +++ b/drivers/iio/industrialio-event.c
> > @@ -477,7 +477,8 @@ int iio_device_register_eventset(struct iio_dev
> > struct attribute **attr;
> >
> > if (!(indio_dev->info->event_attrs ||
> > - iio_check_for_dynamic_events(indio_dev)))
> > + iio_check_for_dynamic_events(indio_dev)) ||
> > + !indio_dev->info->read_event_config)
> > return 0;
> >
> > indio_dev->event_interface =
>