PROCESSOR-SDK-J784S4: 使用sdk-linux-j784s4-evm-10_01_00_05，使用设备树k3-j784s4-evm-csi2-ov5640.dtbo启动linux后，使用devmem2读取dphy寄存器出现内核panic，请问是什么原因？该如何解决？

xiang rong

Prodigy 10 points

Part Number: PROCESSOR-SDK-J784S4

我使用了k3-j784s4-evm-csi2-ov5640.dtbo，启动后，使用lsmod查看，ov5640已正常加载上了，

但是使用devmem2读取dphy寄存器地址0x4504048出现内核panic。

除了0x04504048地址，我还尝试访问了0x4590B00, 0x04504040, 0x04504060, 0x04504100 等寄存器，均出现相同的panic。

14 天前

0 xiang rong 13 天前

Prodigy 10 points

 # This uEnv.txt file can contain additional environment settings that you
# want to set in U-Boot at boot time.  This can be simple variables such
# as the serverip or custom variables.  The format of this file is:
#    variable=value
# NOTE: This file will be evaluated after the bootcmd is run and the
#       bootcmd must be set to load this file if it exists (this is the
#       default on all newer U-Boot images.  This also means that some
#       variables such as bootdelay cannot be changed by this file since
#       it is not evaluated until the bootcmd is run.
psdk_setup_file=.psdk_setup
check_psdk_setup=load mmc 1:1 ${loadaddr} ${psdk_setup_file}

# Reset to the default environment
do_psdk_setup=env default -f -a; saveenv

# Update the Linux hostname based on board_name
# The SK also requires an additional dtbo to boot. Prepend it to name_overlays depending on board_name
uenvcmd=printenv

# Setting the right U-Boot environment variables
dorprocboot=1
name_overlays=ti/k3-j784s4-evm-ethfw.dtbo ti/k3-j784s4-vision-apps.dtbo ti/k3-j784s4-evm-csi2-ov5640.dtbo 
Hi，Ti,
   当我在uEnv将dtbo的加载改成：
name_overlays=ti/k3-j784s4-evm-ethfw.dtbo ti/k3-j784s4-vision-apps.dtbo ti/k3-j784s4-evm-csi2-ov5640.dtbo
   重启demo板后，使用devmem2访问 0x04504048，0x4590B00, 0x04504040, 0x04504060, 0x04504100 等寄存器，未出现panic，
从dtso内看，仅仅是将k3-j784s4-vision-apps这个设备树先加载，然后再加载k3-j784s4-evm-csi2-ov5640，访问dphy寄存器就未出现panic.
// SPDX-License-Identifier: GPL-2.0
/*
 * vision-apps: device-tree overlay
 *
 * Copyright (C) 2019 - 2022 Texas Instruments Incorporated - http://www.ti.com/
 */

/dts-v1/;
/plugin/;

#include <dt-bindings/mux/ti-serdes.h>

&main_r5fss0_core0_shared_memory_queue_region {
	status = "disabled";
};

&main_r5fss0_core0_shared_memory_bufpool_region {
	status = "disabled";
};

#include "k3-j784s4-rtos-memory-map.dtsi"

&main_i2c1 {
    status = "disabled";
};

&main_i2c4 {
	status = "disabled";
};

&main_i2c5 {
	status = "disabled";
};

&dss {
    status = "disabled";
};

&serdes_wiz4 {
    status = "disabled";
};

&ti_csi2rx0 {
    status = "disabled";
};

&ti_csi2rx1 {
    status = "disabled";
};

&ti_csi2rx2 {
    status = "disabled";
};
请问这其中的根本原因是什么？
谢谢！

0 Daniel 1 天前回复 xiang rong

TI__Genius 14845 points

您好

这通常意味着该模块无法从 Linux 内核访问。当您启用 dtbo 时、它已经初始化。您能仔细检查一下吗？

0 xiang rong 1 天前回复 Daniel

Prodigy 10 points

Hi Ti,

demo 板启动后，lsmod查看如下，已经存在j721e_csi2rx，ov5640模块：

root@j784s4-evm:~# lsmod
Module                  Size  Used by
overlay               139264  0
cfg80211              397312  0
bluetooth             503808  2
ecdh_generic           16384  1 bluetooth
ecc                    36864  1 ecdh_generic
rfkill                 28672  3 bluetooth,cfg80211
rpmsg_ctrl             12288  0
rpmsg_char             20480  1 rpmsg_ctrl
panel_edp              32768  0
cdns_csi2rx            16384  1
ti_am335x_adc          16384  0
kfifo_buf              12288  1 ti_am335x_adc
cdns3                  40960  0
cdns_pltfrm            12288  0
cdns_usb_common        20480  1 cdns3
crct10dif_ce           12288  1
snd_soc_j721e_evm      28672  0
display_connector      12288  0
omap_mailbox           12288  11
omap_hwspinlock        12288  0
phy_can_transceiver    12288  3
at24                   16384  0
ti_k3_r5_remoteproc    24576  0
j721e_csi2rx           24576  0
wave5                  94208  0
ov5640                 36864  0
videobuf2_dma_contig    16384  2 j721e_csi2rx,wave5
videobuf2_memops       12288  1 videobuf2_dma_contig
v4l2_mem2mem           32768  1 wave5
snd_soc_davinci_mcasp    32768  2
k3_j72xx_bandgap       12288  0
v4l2_fwnode            20480  2 ov5640,cdns_csi2rx
...
..

我仍然在uEnv.txt使用如下环境变量启动的，此刻devmem2 0x04590B00 w仍然会出现panic.

# Setting the right U-Boot environment variables 
dorprocboot=1 
name_overlays=ti/k3-j784s4-evm-ethfw.dtbo ti/k3-j784s4-evm-csi2-ov5640.dtbo

0 xiang rong 1 天前回复 Daniel

Prodigy 10 points

Hi ti，

查看设备树文件，

主设备树文件中，如上所示：

k3-j784s4-evm-csi2-ov5640.dtso中对status进行了覆盖，改写为okay，

查找驱动文件，从compatible = "ti,j721e-csi2rx-shim";属性，在driver中找到对应的驱动文件为\board-support\ti-linux-kernel-6.6.44+git-ti\drivers\media\platform\ti\j721e-csi2rx\j721e-csi2rx.c，

板子起来后，lsmod查看，确实是加载了j721e_csi2rx.ko，以及ov5640.ko，

查看j721e-csi2rx.c，初始化过程中会注册v4l2设备"TI-CSI2RX"，

板子起来后，查看v4l2设备

root@j784s4-evm:/var# v4l2-ctl --list-devices

wave5-dec (platform:4210000.video-codec):

/dev/video0

/dev/video1

wave5-dec (platform:4220000.video-codec):

/dev/video2

/dev/video3

TI-CSI2RX (platform:4520000.ticsi2rx):

/dev/media0

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PROCESSOR-SDK-J784S4: 使用sdk-linux-j784s4-evm-10_01_00_05，使用设备树k3-j784s4-evm-csi2-ov5640.dtbo启动linux后，使用devmem2读取dphy寄存器出现内核panic，请问是什么原因？该如何解决？