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Date: Sun, 17 Jan 2010 00:25:49 +0100
From: "Rafael J. Wysocki" <rjw@...k.pl>
To: Jesse Barnes <jbarnes@...tuousgeek.org>
Cc: LKML <linux-kernel@...r.kernel.org>,
pm list <linux-pm@...ts.linux-foundation.org>,
dri-devel@...ts.sourceforge.net
Subject: [RFT/RFC] PM: Skip kernel VT switch during suspend/resume with i915/KMS drivers
Hi,
I've been experimenting with the appended patch for some time. It appears to
speed up suspend and resume a bit if the box uses i915 with KMS.
It doesn't seem to break things, but of course more testing would be
appreciated. Comments are welcome as well.
Thanks,
Rafael
---
drivers/gpu/drm/i915/i915_drv.c | 4 ++++
include/linux/suspend.h | 9 +++++++++
kernel/power/suspend.c | 16 +++++++++++++---
3 files changed, 26 insertions(+), 3 deletions(-)
Index: linux-2.6/include/linux/suspend.h
===================================================================
--- linux-2.6.orig/include/linux/suspend.h
+++ linux-2.6/include/linux/suspend.h
@@ -116,6 +116,13 @@ struct platform_suspend_ops {
};
#ifdef CONFIG_SUSPEND
+extern bool vt_switch_enabled;
+
+static inline void disable_suspend_vt_switch(void)
+{
+ vt_switch_enabled = false;
+}
+
/**
* suspend_set_ops - set platform dependent suspend operations
* @ops: The new suspend operations to set.
@@ -143,6 +150,8 @@ extern void arch_suspend_enable_irqs(voi
extern int pm_suspend(suspend_state_t state);
#else /* !CONFIG_SUSPEND */
+static inline void disable_suspend_vt_switch(void) {}
+
#define suspend_valid_only_mem NULL
static inline void suspend_set_ops(struct platform_suspend_ops *ops) {}
Index: linux-2.6/kernel/power/suspend.c
===================================================================
--- linux-2.6.orig/kernel/power/suspend.c
+++ linux-2.6/kernel/power/suspend.c
@@ -18,6 +18,13 @@
#include "power.h"
+/*
+ * If set, switch to a new VT before suspend and switch back to the original
+ * one during resume.
+ */
+bool vt_switch_enabled = true;
+EXPORT_SYMBOL_GPL(vt_switch_enabled);
+
const char *const pm_states[PM_SUSPEND_MAX] = {
[PM_SUSPEND_STANDBY] = "standby",
[PM_SUSPEND_MEM] = "mem",
@@ -82,7 +89,8 @@ static int suspend_prepare(void)
if (!suspend_ops || !suspend_ops->enter)
return -EPERM;
- pm_prepare_console();
+ if (vt_switch_enabled)
+ pm_prepare_console();
error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
if (error)
@@ -100,7 +108,8 @@ static int suspend_prepare(void)
usermodehelper_enable();
Finish:
pm_notifier_call_chain(PM_POST_SUSPEND);
- pm_restore_console();
+ if (vt_switch_enabled)
+ pm_restore_console();
return error;
}
@@ -238,7 +247,8 @@ static void suspend_finish(void)
suspend_thaw_processes();
usermodehelper_enable();
pm_notifier_call_chain(PM_POST_SUSPEND);
- pm_restore_console();
+ if (vt_switch_enabled)
+ pm_restore_console();
}
/**
Index: linux-2.6/drivers/gpu/drm/i915/i915_drv.c
===================================================================
--- linux-2.6.orig/drivers/gpu/drm/i915/i915_drv.c
+++ linux-2.6/drivers/gpu/drm/i915/i915_drv.c
@@ -28,6 +28,7 @@
*/
#include <linux/device.h>
+#include <linux/suspend.h>
#include "drmP.h"
#include "drm.h"
#include "i915_drm.h"
@@ -543,6 +544,9 @@ static int __init i915_init(void)
driver.driver_features &= ~DRIVER_MODESET;
#endif
+ if (driver.driver_features & DRIVER_MODESET)
+ disable_suspend_vt_switch();
+
return drm_init(&driver);
}
--
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