Hey Reyad! Thanks for this explanation, I can see you've invested a lot of time and energy on it, and I really appreciate that! I'll try the steps you suggested tomorrow in hope to get some informative debug info. On Fri, Aug 22, 2014 at 1:15 AM, Reyad Attiyat <reyad.attiyat@xxxxxxxxx> wrote: > I made a mistake in the modprobe configuration file. It should read: > > options hid_sensor_accel_3d dyndbg=+pmfl > options hid_sensor_iio_common dyndbg=+pmfl > options hid_sensor_hub dyndbg=+pmfl > > I used dashes instead of commas for the modules names, which I don't > think works. > > On Thu, Aug 21, 2014 at 1:27 PM, Reyad Attiyat <reyad.attiyat@xxxxxxxxx> wrote: >> Hello Elad, >> >> In order to confirm this is a bug against the newest kernel it is best >> to have steps to reproduce the issue. I understand that >> iio-sensor-proxy fails to read the iio accelerometer. This could be an >> issue with the kernel or with the application's uses of the >> sysfs/device driver interface. >> >> Documentation on the iio subsystem sysfs interface can be found here: >> https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-bus-iio >> >> The basic idea is store an iio device driver interface in the folder >> /sys/bus/iio/devices Each device will have a folder iio:deviceX. In >> each iio device directory there should be a "name" file, and a >> "buffer" and "scanning_elements" folder. The "name" file is simply the >> device driver name, for the accelerometer it should be called >> "accel-3d". >> >> To Test this driver you must enable the scanning elements, in this >> cases the axises (x, y, z), and then enable the buffer. To enable the >> scanning x axis element just write "1" into the file "in_accel_x". >> Example: >> # echo -n 1 > /sys/.../iio:deviceX/scan_elements/in_accel_x_en >> # echo -n 1 > /sys/.../iio:deviceX/scan_elements/in_accel_y_en >> # echo -n 1 > /sys/.../iio:deviceX/scan_elements/in_accel_z_en >> >> Now that we have setup the data we wish to read, we can enable the >> internal iio scan buffer. This is done in a similar way, the iio sysfs >> folder "buffer" contains a file "enable" that we set to 1. Example: >> # echo -n 1 > /sys/bus/iio/devices/iio:deviceX/buffer/enable >> >> To read data from the buffer you must read the character device found >> at /dev/iio:deviceX, where X matches the same number for the syfs >> folder we were modifying. Example: >> >> #cat /dev/iio:deviceX >> >> The above is how the iio-sensor-proxy reads data. You should be aware >> that the charecter device (/dev/iio:deviceX) can only be read once, if >> some other app is already reading from this device it will return >> busy/resource unavailable. Therefore you must ensure nothing is >> reading from it already and that iio-sensor-proxy is disabled. This >> can be checked with command lsof. Example: >> # lsof | grep /dev/iio:deviceX >> >> From the steps above hopefully you can reproduce the same error, of >> not being able to read from the char device on the newest kernel. If >> the above commands all work correctly and data is returned it is >> mostly likely a bug in iio-sensor-proxy or some other part of the >> kernel that that application uses. >> >> To debug this iio device problem further it helps to enable extra >> debugging information. Dynamic debugging allows the user to enable >> switches to give extra information when the kernel prints debugging >> information. Documentation for dynamic debugging can be found here: >> >> https://www.kernel.org/doc/Documentation/dynamic-debug-howto.txt >> >> You can turn on dynamic debugging after boot by writing to the dynamic >> debugging file found in the debugfs interface. It is easier for me to >> enable the feature at boot. This is done by adding a line to the >> modprobe config. This can be found in /etc/modprobe.d/iio.conf. In >> this file add a line that enables dynamic debugging for modules >> hid-sensor-accel-3d and hid-sensor-hub. The lines should be: >> >> options hid-sensor-accel-3d dyndbg=+pflt >> options hid-sensor-hub dyndbg=+pflt >> >> This features needs debugging support in the kernel so it is best to >> build the newest kernel 3.17-rc1 with debugging to get the most output >> in dmesg. >> >> To access the devices usb hid report you can print this from the >> debugfs interface. You sent me "Bus 002 Device 003: ID 0483:91d1 >> STMicroelectronics" from lsusb output. This means the usb device is >> found on bus 2 and is device 3. The usb hid id is 0483:91d1. The first >> half is the vendor id (STMicroelectronics) and the second half is the >> product id. The report information for this device will be found at: >> /sys/kernel/debug/hid/0483:91d1.X/rdesc >> >> Where X is the interface number if your device has more than one. >> >> I hope this information helps you and is all correct. >> If you need any more help please let me know, >> Reyad Attiyat >> >> On Tue, Aug 19, 2014 at 11:51 AM, Elad Alfassa <elad@xxxxxxxxxxxxxxxxx> wrote: >>> Hey. >>> >>> can you instruct me on: >>> >>> 1) how to turn on this dynamic debugging thing? >>> 2) How do I know which directory in /sys/kernel/debug/hid/ is the one >>> for the accelerometer? >>> >>> The USB device ID is Bus 002 Device 003: ID 0483:91d1 STMicroelectronics >>> >>> The weird thing is that after suspend & resume, iio-sensor-proxy can >>> suddenly read the values from the sensor, but it still doesn't rotate >>> the screen. >>> >>> >>> >>> On Tue, Aug 12, 2014 at 7:42 PM, Reyad Attiyat <reyad.attiyat@xxxxxxxxx> wrote: >>>> Hello Elad Alfassa, >>>> >>>> I'm not too sure exactly what has caused such a regression but I will >>>> try and help. There was very little added to the accelerometer driver >>>> in between those releases only, some slight power modifications and >>>> raw read support. >>>> >>>> Have you tried using the sysfs interface for the IIO accelerometer. >>>> Should be located in /sys/bus/iio/devices/iio:devicex/ >>>> In that directory, on the newest kernel, there should be a >>>> in_accel_x_raw file, can you read new data from this? >>>> >>>> Can you provide more detail about the error. Turn on dynamic debugging >>>> for hid-sensor-hub and hid-sensor-accel-3d modules. Then try enabling >>>> the scan elements and the buffer with the sysfs interface and post the >>>> full dmesg output. Also print the HID report description found on >>>> debugfs usually somewhere like >>>> (/sys/kernel/debug/hid/xxxx:xxxx:/rdesc) Maybe with this extra >>>> information the problem will be more clear. >>>> >>>> For a possible fix you can try adding the devices USB HID ID's, for >>>> the sensor hub, to the hid-sensor-hub driver hid_device_id struct. >>>> This will allow adding a quirk for your device and should setup the >>>> power state and enable the sensor hub correctly. >>>> >>>> Good luck, >>>> Reyad Attiyat >>>> >>>> On Mon, Aug 11, 2014 at 8:51 AM, Elad Alfassa <elad@xxxxxxxxxxxxxxxxx> wrote: >>>>> On Mon, Aug 11, 2014 at 3:16 PM, Elad Alfassa <elad@xxxxxxxxxxxxxxxxx> wrote: >>>>>> Hi. >>>>>> >>>>>> I have a Thinkpad Twist, this is a Windows 8 certified machine from >>>>>> around 2012, and it has an accelerometer. >>>>>> Running kernel 3.16.0-1.fc22.x86_64, I'm getting "Resource Temporarily >>>>>> Unavailable" when trying to read from the accelerometer. >>>>>> >>>>>> Tiny bit more details: >>>>>> https://github.com/hadess/iio-sensor-proxy/issues/1 >>>>>> https://sysdev.microsoft.com/en-us/hardware/LPL/ProductDetails.aspx?ProductID=98463&OrganizationID=4733 >>>>>> >>>>>> Is this a known issue? Can I help debug this in any way? >>>>>> >>>>>> >>>>>> Thanks. >>>>>> >>>>>> -- >>>>>> -Elad Alfassa. >>>>> >>>>> Hi. >>>>> Turns out this is a regression - it works well with kernel >>>>> 3.15.8-200.fc20.x86_64 >>>>> I tried reporting this in the kernel bugzilla, but I couldn't find the >>>>> right component for the bug, so I filed it in RHBZ for now. >>>>> https://bugzilla.redhat.com/show_bug.cgi?id=1128760 >>>>> >>>>> >>>>> -- >>>>> -Elad Alfassa. >>>>> -- >>>>> To unsubscribe from this list: send the line "unsubscribe linux-iio" in >>>>> the body of a message to majordomo@xxxxxxxxxxxxxxx >>>>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>> >>> >>> >>> -- >>> -Elad Alfassa. -- -Elad Alfassa. -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
