Oops 的栈信息分析

MTK MT55 F3600 平台

现象：播放MP4文件不断快退或者快进系统重启。

关键log：

Kernel panic - not syncing: x_msg_q_receive(): not support multiple threads call msg_q_receive.

[VDEC]ClrDPB 0 done.
[SWDMX]Seek: Need New Range
[<c0034edc>] (unwind_backtrace+0x0/0xe4) from [<c037fd00>] (panic+0x68/0x188)
[<c037fd00>] (panic+0x68/0x188) from [<bf1bdb74>] (x_msg_q_receive+0x174/0x200 [mtk_mod])
[<bf1bdb74>] (x_msg_q_receive+0x174/0x200 [mtk_mod]) from [<bf3264f4>] (_VDecReceiveEs+0xfc/0x954 [mtk_mod])
[<bf3264f4>] (_VDecReceiveEs+0xfc/0x954 [mtk_mod]) from [<bf327044>] (_VDEC_MainLoop+0x2f8/0x8f4 [mtk_mod])
[IR]PWD:0x00002080 RxIsr Info:0x03030317 0x000000000052c1ea
[IR]u4BitCnt=17
[IR]u4CrystalKey is 0xffffffff
[<bf327044>] (_VDEC_MainLoop+0x2f8/0x8f4 [mtk_mod]) from [<bf1be598>] (ThreadProc+0xa8/0xb8 [mtk_mod])
[<bf1be598>] (ThreadProc+0xa8/0xb8 [mtk_mod]) from [<c0065d74>] (kthread+0x84/0x8c)
[<c0065d74>] (kthread+0x84/0x8c) from [<c00304cc>] (kernel_thread_exit+0x0/0x8)
CPU0: stopping
[<c0034edc>] (unwind_backtrace+0x0/0xe4) from [<c002a368>] (do_IPI+0xc8/0x198)
[<c002a368>] (do_IPI+0xc8/0x198) from [<c002f68c>] (__irq_svc+0x4c/0xe0)
Exception stack(0xc04a5f68 to 0xc04a5fb0)
5f60: 00000000 00000000 c04a5fb0 00000000 c04a4000 c04b34ec
5f80: c04daf44 c03848f4 0000406a 413fc090 00000000 00000000 c4208044 c04a5fb0
5fa0: c0030528 c003052c 60000013 ffffffff
[<c002f68c>] (__irq_svc+0x4c/0xe0) from [<c003052c>] (default_idle+0x24/0x28)
[<c003052c>] (default_idle+0x24/0x28) from [<c0030804>] (cpu_idle+0x7c/0xdc)
[<c0030804>] (cpu_idle+0x7c/0xdc) from [<c0008868>] (start_kernel+0x2bc/0x324)
[<c0008868>] (start_kernel+0x2bc/0x324) from [<0000803c>] (0x803c)

错误原因：not support multiple threads call msg_q_receive.

调用流程：

1 kernel_thread_exit->

2 kthread->

3 ThreadProc->

4 _VDEC_MainLoop->

5 _VDecReceiveEs->

6 x_msg_q_receive-> //此接口有问题

MTK 回复

1，  x_msg_q_receive这个接口之前不支持在多个线程里面使用，现在改成可以support multi thread，这部分改动之前在宜家项目上有上过，MT55CA应该是没有同步过来。

2，  Wait_new_range这个消息之前空转，中间没有delay，导致其他thread没有机会执行。