Tina Linux 如何卸载显示屏驱动模块

[suncw]

首先我想实现一下系统运行的状态下更换显示屏（热插拔），因为更换了屏幕，所以显示屏的相关参数都需要修改。但是fb_fix_screeninfo默认不支持修改。

我想到的方法是将整个模块退出，修改参数，重新初始化显示模块。但是发现退出模块有问题，会打印堆栈。（直接调用disp_module_exit函数进行退出）

请问我这个思路可行吗？或者大家有什么其他方法吗？（使用的硬件是哪吒开发板，全志D1的cpu。软件是linux 5.4）

  [  111.483761] lcd_panel_fun[0].cfg_close_flow is NULL

[  111.494336] BUG: scheduling while atomic: lcdconfig/673/0x00000002

[  111.501266] Modules linked in: cmd_server(O) xt_time xt_multiport xt_mark xt_mac xt_limit xt_comment xt_TCPMSS xt_LOG iptable_filter ipt_REJECT uvcvideo videobuf2_vmalloc videobuf2_memops fuse





[  111.520413] Preemption disabled at:

[  111.520430] [<ffffffdf80cba17a>] lcd_status_set+0x66/0xd2 [cmd_server]

[  111.531635] CPU: 0 PID: 673 Comm: lcdconfig Tainted: G           O      5.4.61 #48

[  111.540069] Call Trace:

[  111.542826] [<ffffffe0000303ce>] walk_stackframe+0x0/0xa0

[  111.548848] [<ffffffe0000305b0>] show_stack+0x2a/0x34

[  111.554516] [<ffffffe000644cd2>] dump_stack+0x20/0x28

[  111.560155] [<ffffffe00004dfda>] __schedule_bug+0x92/0xa4

[  111.566205] [<ffffffe00065a4a8>] __schedule+0x2e0/0x384

[  111.572053] [<ffffffe00065a57e>] schedule+0x32/0xb4

[  111.577493] [<ffffffe00065da94>] schedule_timeout+0x12a/0x228

[  111.583930] [<ffffffe000277658>] disp_delay_ms+0x22/0x2c

[  111.589852] [<ffffffe00027409a>] disp_mgr_disable+0x96/0x1de

[  111.596195] [<ffffffe00027192c>] disp_lcd_disable+0x182/0x388

[  111.602632] [<ffffffe000261a8c>] disp_shutdown+0x54/0x72

[  111.608553] [<ffffffe000267448>] disp_remove+0x30/0x1c6

[  111.614406] [<ffffffe00030321a>] platform_drv_remove+0x1c/0x34

[  111.620917] [<ffffffe000301db4>] device_release_driver_internal+0xb4/0x12a

[  111.628609] [<ffffffe000301e96>] driver_detach+0x3c/0xb2

[  111.634553] [<ffffffe000300d44>] bus_remove_driver+0x40/0x8a

[  111.640863] [<ffffffe000302486>] driver_unregister+0x22/0x48

[  111.647196] [<ffffffe0003032c0>] platform_driver_unregister+0x10/0x18

[  111.654400] [<ffffffe000261fbc>] my_disp_exit+0x1a/0x4c

[  111.660231] [<ffffffdf80cba18a>] lcd_status_set+0x76/0xd2 [cmd_server]

[  111.667537] [<ffffffdf80cba230>] switch_cmd+0x1c/0x7e [cmd_server]

[  111.674453] [<ffffffdf80cba2be>] recv_cmd_msg+0x2c/0x36 [cmd_server]

[  111.681572] [<ffffffe0004d9a76>] netlink_unicast+0x10c/0x16a

[  111.687884] [<ffffffe0004d9c22>] netlink_sendmsg+0x14e/0x2aa

[  111.694229] [<ffffffe000491c3e>] ____sys_sendmsg+0x120/0x152

[  111.700539] [<ffffffe000491cbc>] ___sys_sendmsg+0x4c/0x70

[  111.706584] [<ffffffe0004928d6>] __sys_sendmsg+0x32/0x66

[  111.712526] [<ffffffe00049291c>] sys_sendmsg+0x12/0x1a

[  111.718256] [<ffffffe00002f00a>] ret_from_syscall+0x0/0xe

[  111.724758] [DISP] display_fb_release,line:2204:

[  111.724763] invalid paras fb_id:0 in display_fb_release

[  111.735758] ------------[ cut here ]------------

[  111.740922] WARNING: CPU: 0 PID: 673 at drivers/video/fbdev/core/fbmem.c:1681 unlink_framebuffer+0x16/0xb0

[  111.751682] Modules linked in: cmd_server(O) xt_time xt_multiport xt_mark xt_mac xt_limit xt_comment xt_TCPMSS xt_LOG iptable_filter ipt_REJECT uvcvideo videobuf2_vmalloc videobuf2_memops fuse

[  111.770810] CPU: 0 PID: 673 Comm: lcdconfig Tainted: G        W  O      5.4.61 #48

[  111.779246] sepc: ffffffe00025e3be ra : ffffffe00025eb86 sp : ffffffe01d743950

[  111.787295]  gp : ffffffe00091d3bc tp : ffffffe01d602040 t0 : ffffffe00092a930

[  111.795343]  t1 : 0000000000000064 t2 : 0000000000000009 s0 : ffffffe01d743980

[  111.803391]  s1 : ffffffe01dc8d000 a0 : ffffffe01dc8d000 a1 : 000000000000000a

[  111.811439]  a2 : 00000000000000e6 a3 : ffffffe000888ea0 a4 : 0000000000000000

[  111.819486]  a5 : 0000000000000000 a6 : 00000000000001b0 a7 : 0000000000000000

[  111.827535]  s2 : 000000000000001f s3 : ffffffe00093b4d8 s4 : fffffffffffff000

[  111.835582]  s5 : 0000000000000002 s6 : 0000000000000000 s7 : fffffffffffff000

[  111.843630]  s8 : 0000000000000008 s9 : 000000002966f6b0 s10: ffffffffffffffff

[  111.851678]  s11: 000000000000002d t3 : ffffffe000926b00 t4 : 0000000000002fb0

[  111.859725]  t5 : 0000000000002fb0 t6 : ffffffe000927092

[  111.865642] sstatus: 0000000200000100 sbadaddr: 0000000000000000 scause: 0000000000000003

[  111.874755] ---[ end trace d9a44024af58bd5d ]---

[  111.879906] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000

[  111.889697] Oops [#1]

[  111.892223] Modules linked in: cmd_server(O) xt_time xt_multiport xt_mark xt_mac xt_limit xt_comment xt_TCPMSS xt_LOG iptable_filter ipt_REJECT uvcvideo videobuf2_vmalloc videobuf2_memops fuse

[  111.911341] CPU: 0 PID: 673 Comm: lcdconfig Tainted: G        W  O      5.4.61 #48

[  111.919777] sepc: ffffffe000261060 ra : ffffffe00025eb9c sp : ffffffe01d743980

[  111.927825]  gp : ffffffe00091d3bc tp : ffffffe01d602040 t0 : ffffffe00092a930

[  111.935873]  t1 : 0000000000000064 t2 : 0000000000000009 s0 : ffffffe01d7439a0

[  111.943920]  s1 : ffffffe01dc8d000 a0 : ffffffe01dc8d298 a1 : 000000000000000a

[  111.951968]  a2 : 00000000000000e6 a3 : ffffffe000888ea0 a4 : 0000000000000000

[  111.960016]  a5 : 0000000000000000 a6 : 00000000000001b0 a7 : 0000000000000000

[  111.968064]  s2 : ffffffe01dc8d000 s3 : ffffffe00093b5f0 s4 : fffffffffffff000

[  111.976112]  s5 : 0000000000000002 s6 : 0000000000000000 s7 : fffffffffffff000

[  111.984159]  s8 : 0000000000000008 s9 : 000000002966f6b0 s10: ffffffffffffffff

[  111.992207]  s11: 000000000000002d t3 : ffffffe000926b00 t4 : 0000000000002fb0

[  112.000254]  t5 : 0000000000002fb0 t6 : ffffffe000927092

[  112.006170] sstatus: 0000000200000100 sbadaddr: 0000000000000000 scause: 000000000000000d

[  112.015370] ---[ end trace d9a44024af58bd5e ]---

[  112.020520] note: lcdconfig[673] exited with preempt_count 1

Segmentation fault

cfg_close_flow 初始化中有注册，应该不是空指针。另外将调用处删除后打印一样的堆栈信息，并且调用处有判断空指针，应该和那个空函数指针没关系）