An i.MX50 customer encountered such kernel bug recently. Android UI has no response, because the suspend work queue is blocked:     suspend       pm_suspend         enter_state           suspend_prepare / suspend_finish             pm_prepare_console / pm_restore_console               vt_move_to_console                 vt_waitactive                   vt_event_wait                     wait_event_interruptible Confimed the same bug can also happen on imx6SL which is running linux 3.0.35. e.g. by echo standby/mem > /sys/power/state It takes over thousand suspend/resume cycles to reproduce the problem. The bug fix has been merged since linux 3.6: commit a7b12929be6cc55eab2dac3330fa9f5984e12dda

This article is to show how to use CLK2 for PCIe ref clock for i.MX8MQ. Test Environment  i.MX8MQ + BSP L5.10.52 Background In order to cost down, some customers used CLK2 as PCIe reference clock as below while no external OSC installed, which is different with i.MX8MQ EVK design, so no clock output for PCIe.  Checked L4.14.98_2.3.0 and found it added internal PLL for PCIe clock support. Solution The attached patch based on 4.14.98 can’t be used directly on 5.10.52, the following is the main modification for PLLOUT of PCIe clock. PLLOUT Monitor Configuration Register contains bits to control the clock that will be generated on the CCM clock mapped to CLK2_P/N.        

In January 2013, Adeneo Embedded launched 2 dedicated blogs. These blogs are both run by Adeneo Embedded Windows and Linux experts, multiple time MVP awarded. The goal is to provide the windows and linux communities with specific up-to-date information as well as the latest announcements concerning these two companies. Click here to visit our Windows dedicated blog Click here to visit our Linux dedicated blog Follow, comment and subscribe ! Ce document a été généré à partir de la discussion suivante : Adeneo Embedded experts launch 2 dedicated blogs !

Dynamic debug is designed to allow you to dynamically at runtime  enable/disable  kernel code to obtain additional kernel information. Currently, if ``CONFIG_DYNAMIC_DEBUG`` is set, then all ``pr_debug()``/``dev_dbg()`` and ``print_hex_dump_debug()``/``print_hex_dump_bytes()`` calls can be dynamically enabled per-callsite.    

Platform: i.MX8MP SW:Linux 5.4.70.2.3.0 On current linux BSP, PCIE driver does not support Hot-plug, customers wants to turn off PCIE device to save power, attached is guide. Remove PCIE device driver Suspend PCIE driver Turn off PCIE device power supply Turn on PCIE device power supply Resume PCIE driver Rescan PCIE device Load PCIE device driver

On behalf of Gopise Yuan. A simple sharing for enabling some kernel options for using “lockdep”. It will be useful for detecting some deadlock (spinlock/mutex/…) issue. Validated on L4.14.x, and, found a lock violation…

[中文翻译版] 见附件   原文链接： https://community.nxp.com/docs/DOC-343528 

[中文翻译版] 见附件   原文链接： https://community.nxp.com/docs/DOC-341641 

Linux kernel provide some apis to allow changing dtb node after system booted. But the node change must happen before the driver loading. We can use gereral dtb file and add some dts node after system boot.

Hi All, The new i.MX 6 SL L3.0.35_2.1.0 release is now available on the http://www.freescale.com/site. ·         Files available # Name Description 1 L3.0.35_2.1.0_LINUX_DOCS i.MX   6SoloLite Linux BSP Documentation. Includes Release Notes, Reference Manual,   User guide. API Documentation 2 L3.0.35_2.1.0_LINUX_MMDOCS i.MX 6SoloLite Linux Multimedia Codecs   Documentation. Includes   CODECs Release Notes and User's Guide 3 L3.0.35_2.1.0_ER_SOURCE i.MX   6SoloLite Linux BSP Source Code Files 4 L3.0.35_2.1.0_MM_CODECS i.MX   6SoloLite Linux Multimedia Codecs Sources 5 L3.0.35_2.1.0_AACP_CODECS i.MX   6SoloLite Linux AAC Plus Codec 6 L3.0.35_2.1.0_DEMO_IMAGE i.MX   6SoloLite Linux Binary Demo Files ·         Target HW boards o   i.MX6SL-EVK ·         New features o   Updated thermal equation for i.MX 6SoloLite o   Added Fuse check for all the devices o   Enabled DISPLAY power gating feature on TO1.2 ·         Known issues o   For known issues and limitations please consult the release notes.

This is a summary for the software lockup issue found in the following platform: −i.MX8/8X −Linux 4.14.98_2.3.3   Issue description: •Issue happens during the boot procedure, at the systemd stage. •The symptom of the issue: −From user perspective, the symptom varies, but mainly fall into several types: §At the console, there may be login prompt, but no response (only echo) when input user/password. Unable to login. §Some user service in systemd failed to start. E.g. weston. −When checking the task status using sysrq (w/t), many tasks, including some kernel core tasks stays in “D” (uninterruptable sleep) state. E.g. agetty, login, chvt, etc. •Kernel itself is still alive. This can be verified by triggering some drivers, such as plugin a USB device. Issue can be reproduced on MEK through long time stress.   Please refer to the doc/patch attached for details.

[中文翻译版] 见附件   原文链接： https://community.nxp.com/docs/DOC-343715 

This article is rather short that only mentions the script that is needed to make an iMX93EVK act as a USB mass storage device so that whenever you connect your iMX device to a windows/linux system via USB, it should get enumerated something like a usb drive.  The storage that is used in this example is mmc so the expectation is that you have inserted a mmc card in the slot. Below is the script:- #!/bin/sh   # This composite gadget include function: # - MASS STORAGE     # # Exit status is 0 for PASS, nonzero for FAIL # STATUS=0   # Check if there is udc available, if not, return fail UDC_DIR=/sys/class/udc if test "$(ls -A "$UDC_DIR")"; then echo "The available udc:" for entry in "$UDC_DIR"/* do echo "$entry" done else STATUS=1 echo "No udc available!" exit $STATUS; fi   id=1; udc_name=ci_hdrc.0 #back_file=/dev/mmcblk1 back_file=/tmp/lun0.img   mkdir /sys/kernel/config/usb_gadget/g$id cd /sys/kernel/config/usb_gadget/g$id   # Use NXP VID, i.MX8QXP PID echo 0x1fc9 > idVendor echo 0x12cf > idProduct   mkdir strings/0x409 echo 123456ABCDEF > strings/0x409/serialnumber echo NXP > strings/0x409/manufacturer echo "NXP iMX USB Composite Gadget" > strings/0x409/product   mkdir configs/c.1 mkdir configs/c.1/strings/0x409   echo 5 > configs/c.1/MaxPower echo 0xc0 > configs/c.1/bmAttributes   mkdir functions/mass_storage.1 echo $back_file > functions/mass_storage.1/lun.0/file ln -s functions/mass_storage.1 configs/c.1/   echo $udc_name > UDC First execute the script. After that insert the g_mass_storage module in the kernel by executing :- modprobe g_mass_storage file=/dev/mmcblk1 removable=1 In the dmesg output, you will see something like below:-   After that you can connect a C type USB cable to the USB1 port of imx93evk and the other end to any USB ports of a laptop. The moment it is connected, you would be able to see a USB drive similar to what you get when we connect a pen-drive. 

[中文翻译版] 见附件   原文链接： https://community.nxp.com/docs/DOC-343007 

[中文翻译版] 见附件   原文链接： https://community.nxp.com/docs/DOC-344462 

[中文翻译版] 见附件   原文链接： https://community.nxp.com/docs/DOC-341570 

In L2.6.35_11.09.01_ER BSP Uboot, the MMC driver was updated, but there is issue that when you modified some uboot code, the MMC driver has chance to fail to work. The root cause is that mmc->has_init hasn't been initialized. Sometimes the value will be not zero, then mmc driver will be skipped for initialization. Attached is the patch to fix this issue in L2.6.35_11.09.01_ER BSP Uboot.

Issue: kernel panic when repeating plug/unplug USB device(e.g. USB flash disk) in Linux 4.1.15 The issue is in kernel BLOCK DEVICE, this is not a hardware related issue(happens to all devices running L4.1.15 or L4.4.x), please refer to following link on kernel.org for more details and fixes: blockdev kernel regression (bugzilla 173031) - Patchwork 

The user interface has limited the use of the tool GUI Guider. Getting an interaction only through a mouse or touchscreen can be enough for some use cases. However, sometimes the use case requires to go beyond its limitations. This video/appnote explores the possibility of integrating voice by creating a bridge between a speech recognition technology, such as VIT, and the interface creator GUI Guider. It uses a universal way to link all the voice recognition commands and a wakeword to any interaction created by GUI Guider. The following video shows the steps necessary to create that connection by creating the voice recognition using VIT voice commands and wakewords, create an interface of GUI Guider using a template, how to connect between them using the board i.MX 93 evk and testing it. For more information consult the following links AppNote HTML: https://docs.nxp.com/bundle/AN14270/page/topics/abstract.html?_gl=1*1glzg9k*_ga*NDczMzk4MDYuMTcxNjkyMDI0OA..*_ga_WM5LE0KMSH*MTcxNjkyMDI0OC4xLjEuMTcxNjkyMDcyMy4wLjAuMA AppNote PDF: https://www.nxp.com/docs/en/application-note/AN14270.pdf Associated File: AN14270SW  

What is LGVL? LVGL is a graphics library to run on devices with limited resources. LVGL is fully open-source and has no external dependencies, works with any modern MCU or MPU, and can be used with any (RT)OS or bare metal setup. https://lvgl.io/   What is Framebuffer? The Linux framebuffer (fbdev) is a Linux subsystem used to show graphics on a display, typically manipulated on the system console   How to write on the frame buffer? The device is listed on de device list typically "fb0" on iMX.   1. Stop the window manager (Weston in our BSP) $ systemctl stop weston   2. Write random data on the frame buffer with the next command: $ cat /dev/urandom > /dev/fb0   You should see colored pixels on the screen   3. Restart the window manager. $ systemctl start weston     Cross-compiling the application   1. On the host computer we will clone the LGVL repo: $ git clone https://github.com/lvgl/lv_port_linux_frame_buffer.git -b release/v8.2 $ cd lv_port_linux_frame_buffer $ git submodule update --init --recursive 2. Configure the screen resolution, rotation, and the touch input.       2.1 The resolution is configured in lines 33 and 34 of the main.c disp_drv.hor_res = 1080; disp_drv.ver_res = 1920;           2.2 Rotation configured is on lines 32 and 57 of main.c. disp_drv.sw_rotate = 3; lv_disp_set_rotation(NULL, LV_DISP_ROT_270);     2.3 The touch input is configured on line 450 of lv_drv_conf.h # define EVDEV_NAME "/dev/input/event2"   Note: In my case is on /dev/input/event2 to check the inputs use the command "evtest"   3. Compile the application using the command "make"   Note: To compile the application on your host computer you have to set the environment.   4. Share the file called "demo" with your board and execute it on the board with the command $ ./demo   Note: You have to stop the weston service to run the application.     Notes: Tested on iMX8MN EVK with BSP 6.1.36 Works on Multimedia and Full image.