svn commit: r270850 - in head/sys: i386/i386 i386/include i386/isa x86/acpica

John Baldwin jhb at
Sat Aug 30 17:58:37 UTC 2014

On Saturday, August 30, 2014 05:48:38 PM John Baldwin wrote:
> Author: jhb
> Date: Sat Aug 30 17:48:38 2014
> New Revision: 270850
> URL:
> Log:
>   Save and restore FPU state across suspend and resume.  In earlier
> revisions of this patch, resumectx() called npxresume() directly, but that
> doesn't work because resumectx() runs with a non-standard %cs selector. 
> Instead, all of the FPU suspend/resume handling is done in C.

This mostly fixes suspend and resume in X on a little 32-bit only netbook I 
have.  I needed an additional patch to the i915 code to prevent it from 
tearing down its interrupt handler in suspend and re-establishing it during 
resume (this sort of thing is not needed in drivers and isn't safe because 
suspend runs pinned to CPU 0 and unregistering an interrupt needs to bind to 
the CPU the IDT vector is assigned to).

--- //depot/vendor/freebsd/src/sys/dev/drm2/i915/i915_drv.c
+++ //depot/user/jhb/acpipci/dev/drm2/i915/i915_drv.c
@@ -253,7 +253,9 @@
 			    "GEM idle failed, resume might fail\n");
 			return (error);
+#if 0
@@ -315,7 +317,9 @@
+#if 0
 		/* Resume the modeset for every activated CRTC */

Even with that my one attempt at resuming in X so far seemed to hang in X 
(though the machine was fine and worked fine aside from X hanging).

Curiously, this netbook is able to suspend/resume just fine on the console 
with syscons(4), but the LCD is not turned back on if I suspend/resume with 
vt(4) using the VGA driver.  I think vt(4) should do some of the VESA stuff 
for suspend/resume syscons does when using vt_vga (but not when using one of 
the KMS backends).

John Baldwin

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