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authorLinus Torvalds <torvalds@linux-foundation.org>2013-05-02 19:40:34 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-05-02 19:40:34 -0700
commit20a2078ce7705a6e0722ef5184336eb8657a58d8 (patch)
tree5b927c96516380aa0ecd68d8a609f7cd72120ad5 /kernel
parent0279b3c0ada1d78882f24acf94ac4595bd657a89 (diff)
parent307b9c022720f9de90d58e51743e01e9a42aec59 (diff)
downloadlinux-linaro-stable-20a2078ce7705a6e0722ef5184336eb8657a58d8.tar.gz
Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux
Pull drm updates from Dave Airlie: "This is the main drm pull request for 3.10. Wierd bits: - OMAP drm changes required OMAP dss changes, in drivers/video, so I took them in here. - one more fbcon fix for font handover - VT switch avoidance in pm code - scatterlist helpers for gpu drivers - have acks from akpm Highlights: - qxl kms driver - driver for the spice qxl virtual GPU Nouveau: - fermi/kepler VRAM compression - GK110/nvf0 modesetting support. Tegra: - host1x core merged with 2D engine support i915: - vt switchless resume - more valleyview support - vblank fixes - modesetting pipe config rework radeon: - UVD engine support - SI chip tiling support - GPU registers initialisation from golden values. exynos: - device tree changes - fimc block support Otherwise: - bunches of fixes all over the place." * 'drm-next' of git://people.freedesktop.org/~airlied/linux: (513 commits) qxl: update to new idr interfaces. drm/nouveau: fix build with nv50->nvc0 drm/radeon: fix handling of v6 power tables drm/radeon: clarify family checks in pm table parsing drm/radeon: consolidate UVD clock programming drm/radeon: fix UPLL_REF_DIV_MASK definition radeon: add bo tracking debugfs drm/radeon: add new richland pci ids drm/radeon: add some new SI PCI ids drm/radeon: fix scratch reg handling for UVD fence drm/radeon: allocate SA bo in the requested domain drm/radeon: fix possible segfault when parsing pm tables drm/radeon: fix endian bugs in atom_allocate_fb_scratch() OMAPDSS: TFP410: return EPROBE_DEFER if the i2c adapter not found OMAPDSS: VENC: Add error handling for venc_probe_pdata OMAPDSS: HDMI: Add error handling for hdmi_probe_pdata OMAPDSS: RFBI: Add error handling for rfbi_probe_pdata OMAPDSS: DSI: Add error handling for dsi_probe_pdata OMAPDSS: SDI: Add error handling for sdi_probe_pdata OMAPDSS: DPI: Add error handling for dpi_probe_pdata ...
Diffstat (limited to 'kernel')
-rw-r--r--kernel/power/console.c116
1 files changed, 116 insertions, 0 deletions
diff --git a/kernel/power/console.c b/kernel/power/console.c
index b1dc456474b5..463aa6736751 100644
--- a/kernel/power/console.c
+++ b/kernel/power/console.c
@@ -4,6 +4,7 @@
* Originally from swsusp.
*/
+#include <linux/console.h>
#include <linux/vt_kern.h>
#include <linux/kbd_kern.h>
#include <linux/vt.h>
@@ -14,8 +15,120 @@
static int orig_fgconsole, orig_kmsg;
+static DEFINE_MUTEX(vt_switch_mutex);
+
+struct pm_vt_switch {
+ struct list_head head;
+ struct device *dev;
+ bool required;
+};
+
+static LIST_HEAD(pm_vt_switch_list);
+
+
+/**
+ * pm_vt_switch_required - indicate VT switch at suspend requirements
+ * @dev: device
+ * @required: if true, caller needs VT switch at suspend/resume time
+ *
+ * The different console drivers may or may not require VT switches across
+ * suspend/resume, depending on how they handle restoring video state and
+ * what may be running.
+ *
+ * Drivers can indicate support for switchless suspend/resume, which can
+ * save time and flicker, by using this routine and passing 'false' as
+ * the argument. If any loaded driver needs VT switching, or the
+ * no_console_suspend argument has been passed on the command line, VT
+ * switches will occur.
+ */
+void pm_vt_switch_required(struct device *dev, bool required)
+{
+ struct pm_vt_switch *entry, *tmp;
+
+ mutex_lock(&vt_switch_mutex);
+ list_for_each_entry(tmp, &pm_vt_switch_list, head) {
+ if (tmp->dev == dev) {
+ /* already registered, update requirement */
+ tmp->required = required;
+ goto out;
+ }
+ }
+
+ entry = kmalloc(sizeof(*entry), GFP_KERNEL);
+ if (!entry)
+ goto out;
+
+ entry->required = required;
+ entry->dev = dev;
+
+ list_add(&entry->head, &pm_vt_switch_list);
+out:
+ mutex_unlock(&vt_switch_mutex);
+}
+EXPORT_SYMBOL(pm_vt_switch_required);
+
+/**
+ * pm_vt_switch_unregister - stop tracking a device's VT switching needs
+ * @dev: device
+ *
+ * Remove @dev from the vt switch list.
+ */
+void pm_vt_switch_unregister(struct device *dev)
+{
+ struct pm_vt_switch *tmp;
+
+ mutex_lock(&vt_switch_mutex);
+ list_for_each_entry(tmp, &pm_vt_switch_list, head) {
+ if (tmp->dev == dev) {
+ list_del(&tmp->head);
+ break;
+ }
+ }
+ mutex_unlock(&vt_switch_mutex);
+}
+EXPORT_SYMBOL(pm_vt_switch_unregister);
+
+/*
+ * There are three cases when a VT switch on suspend/resume are required:
+ * 1) no driver has indicated a requirement one way or another, so preserve
+ * the old behavior
+ * 2) console suspend is disabled, we want to see debug messages across
+ * suspend/resume
+ * 3) any registered driver indicates it needs a VT switch
+ *
+ * If none of these conditions is present, meaning we have at least one driver
+ * that doesn't need the switch, and none that do, we can avoid it to make
+ * resume look a little prettier (and suspend too, but that's usually hidden,
+ * e.g. when closing the lid on a laptop).
+ */
+static bool pm_vt_switch(void)
+{
+ struct pm_vt_switch *entry;
+ bool ret = true;
+
+ mutex_lock(&vt_switch_mutex);
+ if (list_empty(&pm_vt_switch_list))
+ goto out;
+
+ if (!console_suspend_enabled)
+ goto out;
+
+ list_for_each_entry(entry, &pm_vt_switch_list, head) {
+ if (entry->required)
+ goto out;
+ }
+
+ ret = false;
+out:
+ mutex_unlock(&vt_switch_mutex);
+ return ret;
+}
+
int pm_prepare_console(void)
{
+ if (!pm_vt_switch())
+ return 0;
+
orig_fgconsole = vt_move_to_console(SUSPEND_CONSOLE, 1);
if (orig_fgconsole < 0)
return 1;
@@ -26,6 +139,9 @@ int pm_prepare_console(void)
void pm_restore_console(void)
{
+ if (!pm_vt_switch())
+ return;
+
if (orig_fgconsole >= 0) {
vt_move_to_console(orig_fgconsole, 0);
vt_kmsg_redirect(orig_kmsg);