From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Wessel Subject: Re: Any SYSRQ key to force mode switch to console mode when using KMS? Date: Wed, 06 Oct 2010 13:44:48 -0500 Message-ID: <4CACC3A0.4090300@windriver.com> References: <19601.1301.803816.92851@elektron.ikp.physik.tu-darmstadt.de> <20100921151033.80e61747.randy.dunlap@oracle.com> <19609.53242.674915.369484@elektron.ikp.physik.tu-darmstadt.de> <4C9A1FB7.9050902@oracle.com> <19611.8986.142128.168878@elektron.ikp.physik.tu-darmstadt.de> <19611.20403.865248.695829@elektron.ikp.physik.tu-darmstadt.de> <20100923080212.ca4be1f6.rdunlap@xenotime.net> <19611.32996.817920.499437@elektron.ikp.physik.tu-darmstadt.de> <20100924080707.ba98fa1e.rdunlap@xenotime.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20100924080707.ba98fa1e.rdunlap@xenotime.net> Sender: linux-kernel-owner@vger.kernel.org To: Uwe Bonnes Cc: Randy Dunlap , linux-kernel@vger.kernel.org, David Airlie , dri-devel@lists.freedesktop.org, Jesse Barnes List-Id: dri-devel@lists.freedesktop.org On 09/24/2010 10:07 AM, Randy Dunlap wrote: > On Thu, 23 Sep 2010 18:31:32 +0200 Uwe Bonnes wrote: > > [just adding cc's] > > >>>>>>> "Randy" == Randy Dunlap writes: >>>>>>> >> Randy> Is CONFIG_DRM_KMS_HELPER enabled in your kernel .config file? If >> Randy> not, we need to find out how to enable it (there is no kconfig >> Randy> prompt for it). >> >> Yes, it is enabled >> >> Randy> Can you check if Alt-Sysrq-H (help) lists V for "force-fb(V)"? >> Yes, it is listed. >> >> And yes, my last experiments where with ALT-CTL-sysreq, so doomed for non >> function due to operator error. >> >> However: >> When running X, X.Org X Server 1.9.0 on Thinkpad R50 RV250, Alt-Sysrq-v >> switches to an all-black display. By console switching with ALT-CLT-F1 I >> get back to the booting console and ALT-CLT-F7 brings me back to X. Running >> on the console and calling Alt-Sysrq-v prints >> SysRq : Restore framebuffer console >> >> Is there some omission by the distribution or my setup that Alt-Sysrq-v when >> running X results in an all-black screen? >> >> And when I hit the hibernate problem, the screen stays black even with a >> console switch after Alt-Sysrq-v >> >> I am not exactly sure what you are looking for but alt-sysrq-v might not tell you a whole lot because an escape back to the text console that was not actively receiving printk's or crash data is going to in general provide you with a black screen. If you were interested in something a bit more invasive such as a collecting a process listing or examining the dmesg output you might consider jumping into kdb. echo kbd > /sys/module/kgdboc/parameters/kgdboc Then you would do the "alt-sysrq v" followed by "alt-sysrq g". From there you could then run dmesg, and your screen would no longer be blank in theory. :-) We do have some patches for the RV250 for atomic kernel mode setting plus kdb support but they are not merged to the mainline kernels as of yet. Jason.