CINXE.COM
LKML: Olaf Hering: Re: [PATCH] Adding ctrl-o sysrq hack support to 8250 driver
<?xml version="1.0" encoding="UTF-8" standalone="yes"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>LKML: Olaf Hering: Re: [PATCH] Adding ctrl-o sysrq hack support to 8250 driver</title><link href="/css/message.css" rel="stylesheet" type="text/css" /><link href="/css/wrap.css" rel="alternate stylesheet" type="text/css" title="wrap" /><link href="/css/nowrap.css" rel="stylesheet" type="text/css" title="nowrap" /><link href="/favicon.ico" rel="shortcut icon" /><script src="/js/simple-calendar.js" type="text/javascript"></script><script src="/js/styleswitcher.js" type="text/javascript"></script><link rel="alternate" type="application/rss+xml" title="lkml.org : last 100 messages" href="/rss.php" /><link rel="alternate" type="application/rss+xml" title="lkml.org : last messages by Olaf Hering" href="/groupie.php?aid=2984" /><!--Matomo--><script> var _paq = window._paq = window._paq || []; /* tracker methods like "setCustomDimension" should be called before "trackPageView" */ _paq.push(["setDoNotTrack", true]); _paq.push(["disableCookies"]); _paq.push(['trackPageView']); _paq.push(['enableLinkTracking']); (function() { var u="//m.lkml.org/"; _paq.push(['setTrackerUrl', u+'matomo.php']); _paq.push(['setSiteId', '1']); var d=document, g=d.createElement('script'), s=d.getElementsByTagName('script')[0]; g.async=true; g.src=u+'matomo.js'; s.parentNode.insertBefore(g,s); })(); </script><!--End Matomo Code--></head><body onload="es.jasper.simpleCalendar.init();" itemscope="itemscope" itemtype="http://schema.org/BlogPosting"><table border="0" cellpadding="0" cellspacing="0"><tr><td width="180" align="center"><a href="/"><img style="border:0;width:135px;height:32px" src="/images/toprowlk.gif" alt="lkml.org" /></a></td><td width="32">聽</td><td class="nb"><div><a class="nb" href="/lkml"> [lkml]</a> 聽 <a class="nb" href="/lkml/2005"> [2005]</a> 聽 <a class="nb" href="/lkml/2005/12"> [Dec]</a> 聽 <a class="nb" href="/lkml/2005/12/9"> [9]</a> 聽 <a class="nb" href="/lkml/last100"> [last100]</a> 聽 <a href="/rss.php"><img src="/images/rss-or.gif" border="0" alt="RSS Feed" /></a></div><div>Views: <a href="#" class="nowrap" onclick="setActiveStyleSheet('wrap');return false;">[wrap]</a><a href="#" class="wrap" onclick="setActiveStyleSheet('nowrap');return false;">[no wrap]</a> 聽 <a class="nb" href="/lkml/mheaders/2005/12/9/201" onclick="this.href='/lkml/headers'+'/2005/12/9/201';">[headers]</a>聽 <a href="/lkml/bounce/2005/12/9/201">[forward]</a>聽 </div></td><td width="32">聽</td></tr><tr><td valign="top"><div class="es-jasper-simpleCalendar" baseurl="/lkml/"></div><div class="threadlist">Messages in this thread</div><ul class="threadlist"><li class="root"><a href="/lkml/2005/12/9/75">First message in thread</a></li><li><a href="/lkml/2005/12/9/105">Erik Mouw</a><ul><li><a href="/lkml/2005/12/9/119">Olaf Hering</a><ul><li class="origin"><a href="">Olaf Hering</a></li></ul></li><li><a href="/lkml/2005/12/9/136">Russell King</a><ul><li><a href="/lkml/2005/12/12/48">Olaf Hering</a><ul><li><a href="/lkml/2006/1/3/73">Olaf Hering</a></li></ul></li></ul></li></ul></li></ul><div class="threadlist">Patch in this message</div><ul class="threadlist"><li><a href="/lkml/diff/2005/12/9/201/1">Get diff 1</a></li></ul></td><td width="32" rowspan="2" class="c" valign="top"><img src="/images/icornerl.gif" width="32" height="32" alt="/" /></td><td class="c" rowspan="2" valign="top" style="padding-top: 1em"><table><tr><td><table><tr><td class="lp">Date</td><td class="rp" itemprop="datePublished">Fri, 9 Dec 2005 21:47:36 +0100</td></tr><tr><td class="lp">From</td><td class="rp" itemprop="author">Olaf Hering <></td></tr><tr><td class="lp">Subject</td><td class="rp" itemprop="name">Re: [PATCH] Adding ctrl-o sysrq hack support to 8250 driver</td></tr></table></td><td></td></tr></table><pre itemprop="articleBody"> On Fri, Dec 09, Olaf Hering wrote:<br /><br />> > If it is a POWER4-only problem, why isn't there a dependency on<br />> > CONFIG_POWER4 over here? I don't like to have the ctrl-o sysrq stuff<br />> > enabled on my regular PC if it only matters to some rare (in absolute<br />> > numbers) system.<br /><br />The system with the build tree on it just crashed hard.<br />Thats what I saved from the screen session:<br /><br />Index: linux-2.6.15-rc5-olh/drivers/serial/8250.c<br />===================================================================<br />--- linux-2.6.15-rc5-olh.orig/drivers/serial/8250.c<br />+++ linux-2.6.15-rc5-olh/drivers/serial/8250.c<br />@@ -85,6 +85,8 @@ static unsigned int share_irqs = SERIAL8<br /> #define CONFIG_SERIAL_MANY_PORTS 1<br /> #endif<br /><br />+#define arch_8250_sysrq_via_ctrl_o(x) (0)<br />+<br /> /*<br /> * HUB6 is always on. This will be removed once the header<br /> * files have been cleaned.<br />@@ -1154,6 +1156,10 @@ receive_chars(struct uart_8250_port *up,<br /> */<br /> }<br /> ch = serial_inp(up, UART_RX);<br />+<br />+ if (arch_8250_sysrq_via_ctrl_o(ch, &up->port))<br />+ goto ignore_char;<br />+<br /> flag = TTY_NORMAL;<br /> up->port.icount.rx++;<br /><br />Index: linux-2.6.15-rc5-olh/include/asm-powerpc/serial.h<br />===================================================================<br />--- linux-2.6.15-rc5-olh.orig/include/asm-powerpc/serial.h<br />+++ linux-2.6.15-rc5-olh/include/asm-powerpc/serial.h<br />@@ -15,4 +15,11 @@<br /> /* Default baud base if not found in device-tree */<br /> #define BASE_BAUD ( 1843200 / 16 )<br /><br />+<br />+#if defined(SUPPORT_SYSRQ) && defined(CONFIG_PPC_PSERIES)<br />+ /* Handle the SysRq ^O Hack, but only on the system console */<br />+#undef arch_8250_sysrq_via_ctrl_o<br />+#define arch_8250_sysrq_via_ctrl_o(ch, port) ((ch) == '\x0f' && uart_handle_break((port)))<br />+#endif<br />+<br /> #endif /* _PPC64_SERIAL_H */<br /><br /><br />-- <br />short story of a lazy sysadmin:<br /> alias appserv=wotan<br />-<br />To unsubscribe from this list: send the line "unsubscribe linux-kernel" in<br />the body of a message to majordomo@vger.kernel.org<br />More majordomo info at <a href="http://vger.kernel.org/majordomo-info.html">http://vger.kernel.org/majordomo-info.html</a><br />Please read the FAQ at <a href="http://www.tux.org/lkml/">http://www.tux.org/lkml/</a><br /><br /></pre></td><td width="32" rowspan="2" class="c" valign="top"><img src="/images/icornerr.gif" width="32" height="32" alt="\" /></td></tr><tr><td align="right" valign="bottom"> 聽 </td></tr><tr><td align="right" valign="bottom">聽</td><td class="c" valign="bottom" style="padding-bottom: 0px"><img src="/images/bcornerl.gif" width="32" height="32" alt="\" /></td><td class="c">聽</td><td class="c" valign="bottom" style="padding-bottom: 0px"><img src="/images/bcornerr.gif" width="32" height="32" alt="/" /></td></tr><tr><td align="right" valign="top" colspan="2"> 聽 </td><td class="lm">Last update: 2005-12-09 21:50 聽聽 [from the cache]<br />漏2003-2020 <a href="http://blog.jasper.es/"><span itemprop="editor">Jasper Spaans</span></a>|hosted at <a href="https://www.digitalocean.com/?refcode=9a8e99d24cf9">Digital Ocean</a> and my Meterkast|<a href="http://blog.jasper.es/categories.html#lkml-ref">Read the blog</a></td><td>聽</td></tr></table><script language="javascript" src="/js/styleswitcher.js" type="text/javascript"></script></body></html>