{"action":"created","issue":{"url":"https://api.github.com/repos/RIOT-OS/RIOT/issues/3943","labels_url":"https://api.github.com/repos/RIOT-OS/RIOT/issues/3943/labels{/name}","comments_url":"https://api.github.com/repos/RIOT-OS/RIOT/issues/3943/comments","events_url":"https://api.github.com/repos/RIOT-OS/RIOT/issues/3943/events","html_url":"https://github.com/RIOT-OS/RIOT/issues/3943","id":107944050,"number":3943,"title":"samr21-xpro: UART hangs","user":{"login":"OlegHahm","id":1590423,"avatar_url":"https://avatars.githubusercontent.com/u/1590423?v=3","gravatar_id":"","url":"https://api.github.com/users/OlegHahm","html_url":"https://github.com/OlegHahm","followers_url":"https://api.github.com/users/OlegHahm/followers","following_url":"https://api.github.com/users/OlegHahm/following{/other_user}","gists_url":"https://api.github.com/users/OlegHahm/gists{/gist_id}","starred_url":"https://api.github.com/users/OlegHahm/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/OlegHahm/subscriptions","organizations_url":"https://api.github.com/users/OlegHahm/orgs","repos_url":"https://api.github.com/users/OlegHahm/repos","events_url":"https://api.github.com/users/OlegHahm/events{/privacy}","received_events_url":"https://api.github.com/users/OlegHahm/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/RIOT-OS/RIOT/labels/arm","name":"arm","color":"dddddd"},{"url":"https://api.github.com/repos/RIOT-OS/RIOT/labels/bug","name":"bug","color":"fc2929"}],"state":"open","locked":false,"assignee":{"login":"haukepetersen","id":620834,"avatar_url":"https://avatars.githubusercontent.com/u/620834?v=3","gravatar_id":"","url":"https://api.github.com/users/haukepetersen","html_url":"https://github.com/haukepetersen","followers_url":"https://api.github.com/users/haukepetersen/followers","following_url":"https://api.github.com/users/haukepetersen/following{/other_user}","gists_url":"https://api.github.com/users/haukepetersen/gists{/gist_id}","starred_url":"https://api.github.com/users/haukepetersen/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/haukepetersen/subscriptions","organizations_url":"https://api.github.com/users/haukepetersen/orgs","repos_url":"https://api.github.com/users/haukepetersen/repos","events_url":"https://api.github.com/users/haukepetersen/events{/privacy}","received_events_url":"https://api.github.com/users/haukepetersen/received_events","type":"User","site_admin":false},"milestone":{"url":"https://api.github.com/repos/RIOT-OS/RIOT/milestones/12","html_url":"https://github.com/RIOT-OS/RIOT/milestones/Release%202015.09","labels_url":"https://api.github.com/repos/RIOT-OS/RIOT/milestones/12/labels","id":1088995,"number":12,"title":"Release 2015.09","description":"This release aims mainly to include the gnrc network stack as the new default IPv6/6LoWPAN stack.","creator":{"login":"OlegHahm","id":1590423,"avatar_url":"https://avatars.githubusercontent.com/u/1590423?v=3","gravatar_id":"","url":"https://api.github.com/users/OlegHahm","html_url":"https://github.com/OlegHahm","followers_url":"https://api.github.com/users/OlegHahm/followers","following_url":"https://api.github.com/users/OlegHahm/following{/other_user}","gists_url":"https://api.github.com/users/OlegHahm/gists{/gist_id}","starred_url":"https://api.github.com/users/OlegHahm/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/OlegHahm/subscriptions","organizations_url":"https://api.github.com/users/OlegHahm/orgs","repos_url":"https://api.github.com/users/OlegHahm/repos","events_url":"https://api.github.com/users/OlegHahm/events{/privacy}","received_events_url":"https://api.github.com/users/OlegHahm/received_events","type":"User","site_admin":false},"open_issues":20,"closed_issues":559,"state":"open","created_at":"2015-04-29T10:11:27Z","updated_at":"2015-09-24T15:57:17Z","due_on":"2015-09-17T22:00:00Z","closed_at":null},"comments":11,"created_at":"2015-09-23T15:18:41Z","updated_at":"2015-09-24T16:08:04Z","closed_at":null,"body":"On samr21-xpro using the `gnrc_border_router` example, it happens that the shell will stop working. Connecting with gdb indicates that it hangs in\r\n```\r\nuart_write_blocking (uart=uart@entry=UART_0, data=62 '>') at /home/oleg/git/RIOT/cpu/samd21/periph/uart.c:135\r\n135\t    while (!(_uart(uart)->INTFLAG.reg & SERCOM_USART_INTFLAG_DRE));\r\n```\r\nwhile a backtrace shows that this originates from\r\n```\r\n#0  uart_write_blocking (uart=uart@entry=UART_0, data=62 '>') at /home/oleg/git/RIOT/cpu/samd21/periph/uart.c:135\r\n#1  0x00000604 in uart_stdio_write (\r\n    buffer=0x200060d9 \" ba::1\", ' ' <repeats 26 times>, \"5  36:32:48:33:46:dd:7c:2a   UNREACHABLE REG\\n\\nSMA Retries: 4 \\n\\255\\347\\n:2G\\203\\254\\373\\325\\335\\305k\\371\\311\\345\\n\\233\\351\\210S\\333B\\201>\\361r\\274Zx\\252\\357\\341\\t\\256\\312\\061\\f}\\366}\\366\\367\\370خ\\v'\\247\\257_\\273<\\305{\\343\\303\\337Ⱥ\\327\\335ǊŘ\\207#\\271\\005-/)H;۷\\311\\367O\\337\\036\\301^\\304\\363T\\243\\365\\363\\205\\352\\222\\067\\346L\\315\\315\\342y\\216\\200_\\362\\036`\"..., len=2) at /home/oleg/git/RIOT/sys/uart_stdio/uart_stdio.c:94\r\n#2  0x0000010a in _write_r (r=<optimized out>, fd=<optimized out>, data=<optimized out>, count=<optimized out>) at /home/oleg/git/RIOT/sys/newlib/syscalls.c:204\r\n#3  0x0000cf86 in __swrite ()\r\n#4  0x0000c93e in __sflush_r ()\r\n#5  0x0000c99e in _fflush_r ()\r\n#6  0x0000c9c6 in fflush ()\r\n#7  0x00007aa8 in print_prompt () at /home/oleg/git/RIOT/sys/shell/shell.c:271\r\n#8  0x00007ac0 in shell_run (shell_commands=0xf27 <main+26>, shell_commands@entry=0xe288 <shell_commands>, line_buf=0x61006568 \"\", line_buf@entry=0x20000800 <main_stack+1332> \"ncache\", \r\n    len=5, len@entry=128) at /home/oleg/git/RIOT/sys/shell/shell.c:275\r\n#9  0x00000f26 in main () at /home/oleg/git/RIOT/examples/gnrc_border_router/main.c:46\r\n```"},"comment":{"url":"https://api.github.com/repos/RIOT-OS/RIOT/issues/comments/142974750","html_url":"https://github.com/RIOT-OS/RIOT/issues/3943#issuecomment-142974750","issue_url":"https://api.github.com/repos/RIOT-OS/RIOT/issues/3943","id":142974750,"user":{"login":"OlegHahm","id":1590423,"avatar_url":"https://avatars.githubusercontent.com/u/1590423?v=3","gravatar_id":"","url":"https://api.github.com/users/OlegHahm","html_url":"https://github.com/OlegHahm","followers_url":"https://api.github.com/users/OlegHahm/followers","following_url":"https://api.github.com/users/OlegHahm/following{/other_user}","gists_url":"https://api.github.com/users/OlegHahm/gists{/gist_id}","starred_url":"https://api.github.com/users/OlegHahm/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/OlegHahm/subscriptions","organizations_url":"https://api.github.com/users/OlegHahm/orgs","repos_url":"https://api.github.com/users/OlegHahm/repos","events_url":"https://api.github.com/users/OlegHahm/events{/privacy}","received_events_url":"https://api.github.com/users/OlegHahm/received_events","type":"User","site_admin":false},"created_at":"2015-09-24T16:08:04Z","updated_at":"2015-09-24T16:08:04Z","body":"Yupp, just figured out, there need to be traffic on the second UART, I guess."}}