[PATCH RFC v2] vga_switcheroo: restore mux and power states upon resume from hibernation.
Jani Nikula
jani.nikula at linux.intel.com
Fri Sep 5 04:28:54 PDT 2014
On Fri, 31 Jan 2014, Alex Deucher <alexdeucher at gmail.com> wrote:
> On Thu, Jan 30, 2014 at 6:46 PM, Stefan Demharter
> <stefan.demharter at gmx.net> wrote:
>> Saves the current state of the mux and restores it upon resume from hibernation.
>> This is needed for muxed systems because the state of the mux doesn't survive a
>> hibernation-resume cycle. Furthermore also restores the power state of a GPU
>> to OFF after resume from hibernation if it was OFF before hibernation.
>>
>> Signed-off-by: Stefan Demharter <stefan.demharter at gmx.net>
>
> Reviewed-by: Alex Deucher <alexander.deucher at amd.com>
Despite the review, looks like this one has fallen between the
cracks. There's some comments from Chris at [1].
Dave?
BR,
Jani.
[1] https://bugs.freedesktop.org/show_bug.cgi?id=70863#c4
>
>> ---
>> drivers/gpu/vga/vga_switcheroo.c | 96 +++++++++++++++++++++++++++++++++++-----
>> 1 file changed, 85 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/gpu/vga/vga_switcheroo.c b/drivers/gpu/vga/vga_switcheroo.c
>> index ec0ae2d..85f41b9 100644
>> --- a/drivers/gpu/vga/vga_switcheroo.c
>> +++ b/drivers/gpu/vga/vga_switcheroo.c
>> @@ -28,6 +28,7 @@
>> #include <linux/console.h>
>> #include <linux/vga_switcheroo.h>
>> #include <linux/pm_runtime.h>
>> +#include <linux/suspend.h>
>>
>> #include <linux/vgaarb.h>
>>
>> @@ -72,6 +73,64 @@ static struct vgasr_priv vgasr_priv = {
>> .clients = LIST_HEAD_INIT(vgasr_priv.clients),
>> };
>>
>> +#define MUX_STATE_UNDEFINED (-1)
>> +/*
>> + * The next variable stores the state of the mux
>> + * so it can be restored upon resume from hibernation.
>> + */
>> +static int mux_state = MUX_STATE_UNDEFINED;
>> +
>> +static void vga_restore_mux(void)
>> +{
>> + if (mux_state != MUX_STATE_UNDEFINED) {
>> + int ret;
>> + pr_info("vga_switcheroo: restoring mux state to %s\n",
>> + mux_state == VGA_SWITCHEROO_IGD ? "IGD" : "DIS");
>> +
>> + ret = vgasr_priv.handler->switchto(mux_state);
>> + if (ret)
>> + pr_warn("vga_switcheroo: mux switch failed (%d)\n", ret);
>> + }
>> +}
>> +
>> +static void vga_restore_power_state(void)
>> +{
>> + struct vga_switcheroo_client *client;
>> +
>> + if (!vgasr_priv.handler->power_state)
>> + return;
>> +
>> + list_for_each_entry(client, &vgasr_priv.clients, list) {
>> + if (client_is_vga(client) && client->pwr_state == VGA_SWITCHEROO_OFF) {
>> + pr_info("vga_switcheroo: setting power state of %s to OFF\n",
>> + client->id == VGA_SWITCHEROO_IGD ? "IGD" : "DIS");
>> + vgasr_priv.handler->power_state(client->id, client->pwr_state);
>> + }
>> + }
>> +}
>> +
>> +/*
>> + * Handle resume from hibernation:
>> + * Restore mux state and power states for switcheroo controlled GPUs.
>> + */
>> +static int vga_resume(struct notifier_block *nb, unsigned long action, void *unused)
>> +{
>> + switch (action) {
>> + case PM_POST_HIBERNATION:
>> + mutex_lock(&vgasr_mutex);
>> + vga_restore_mux();
>> + vga_restore_power_state();
>> + mutex_unlock(&vgasr_mutex);
>> + break;
>> + }
>> + return 0;
>> +}
>> +
>> +static struct notifier_block vga_switcheroo_pm_nb = {
>> + .notifier_call = vga_resume,
>> + .priority = 0,
>> +};
>> +
>> static bool vga_switcheroo_ready(void)
>> {
>> /* we're ready if we get two clients + handler */
>> @@ -84,6 +143,8 @@ static void vga_switcheroo_enable(void)
>> int ret;
>> struct vga_switcheroo_client *client;
>>
>> + pr_info("vga_switcheroo: enabled\n");
>> +
>> /* call the handler to init */
>> if (vgasr_priv.handler->init)
>> vgasr_priv.handler->init();
>> @@ -99,6 +160,15 @@ static void vga_switcheroo_enable(void)
>> }
>> vga_switcheroo_debugfs_init(&vgasr_priv);
>> vgasr_priv.active = true;
>> + register_pm_notifier(&vga_switcheroo_pm_nb);
>> +}
>> +
>> +void vga_switcheroo_disable(void)
>> +{
>> + unregister_pm_notifier(&vga_switcheroo_pm_nb);
>> + vgasr_priv.active = false;
>> + vga_switcheroo_debugfs_fini(&vgasr_priv);
>> + pr_info("vga_switcheroo: disabled\n");
>> }
>>
>> int vga_switcheroo_register_handler(struct vga_switcheroo_handler *handler)
>> @@ -111,7 +181,6 @@ int vga_switcheroo_register_handler(struct vga_switcheroo_handler *handler)
>>
>> vgasr_priv.handler = handler;
>> if (vga_switcheroo_ready()) {
>> - printk(KERN_INFO "vga_switcheroo: enabled\n");
>> vga_switcheroo_enable();
>> }
>> mutex_unlock(&vgasr_mutex);
>> @@ -124,9 +193,7 @@ void vga_switcheroo_unregister_handler(void)
>> mutex_lock(&vgasr_mutex);
>> vgasr_priv.handler = NULL;
>> if (vgasr_priv.active) {
>> - pr_info("vga_switcheroo: disabled\n");
>> - vga_switcheroo_debugfs_fini(&vgasr_priv);
>> - vgasr_priv.active = false;
>> + vga_switcheroo_disable();
>> }
>> mutex_unlock(&vgasr_mutex);
>> }
>> @@ -155,7 +222,6 @@ static int register_client(struct pci_dev *pdev,
>> vgasr_priv.registered_clients++;
>>
>> if (vga_switcheroo_ready()) {
>> - printk(KERN_INFO "vga_switcheroo: enabled\n");
>> vga_switcheroo_enable();
>> }
>> mutex_unlock(&vgasr_mutex);
>> @@ -235,9 +301,7 @@ void vga_switcheroo_unregister_client(struct pci_dev *pdev)
>> kfree(client);
>> }
>> if (vgasr_priv.active && vgasr_priv.registered_clients < 2) {
>> - printk(KERN_INFO "vga_switcheroo: disabled\n");
>> - vga_switcheroo_debugfs_fini(&vgasr_priv);
>> - vgasr_priv.active = false;
>> + vga_switcheroo_disable();
>> }
>> mutex_unlock(&vgasr_mutex);
>> }
>> @@ -262,10 +326,11 @@ static int vga_switcheroo_show(struct seq_file *m, void *v)
>> int i = 0;
>> mutex_lock(&vgasr_mutex);
>> list_for_each_entry(client, &vgasr_priv.clients, list) {
>> - seq_printf(m, "%d:%s%s:%c:%s%s:%s\n", i,
>> + seq_printf(m, "%d:%s%s:%c%s:%s%s:%s\n", i,
>> client_id(client) == VGA_SWITCHEROO_DIS ? "DIS" : "IGD",
>> client_is_vga(client) ? "" : "-Audio",
>> client->active ? '+' : ' ',
>> + client_id(client) == mux_state ? "mux" : "",
>> client->driver_power_control ? "Dyn" : "",
>> client->pwr_state ? "Pwr" : "Off",
>> pci_name(client->pdev));
>> @@ -304,6 +369,15 @@ static int vga_switchoff(struct vga_switcheroo_client *client)
>> return 0;
>> }
>>
>> +static int vga_switchto(int client_id)
>> +{
>> + int ret = vgasr_priv.handler->switchto(client_id);
>> +
>> + if (ret == 0)
>> + mux_state = client_id;
>> + return ret;
>> +}
>> +
>> static void set_audio_state(int id, int state)
>> {
>> struct vga_switcheroo_client *client;
>> @@ -353,7 +427,7 @@ static int vga_switchto_stage2(struct vga_switcheroo_client *new_client)
>> console_unlock();
>> }
>>
>> - ret = vgasr_priv.handler->switchto(new_client->id);
>> + ret = vga_switchto(new_client->id);
>> if (ret)
>> return ret;
>>
>> @@ -468,7 +542,7 @@ vga_switcheroo_debugfs_write(struct file *filp, const char __user *ubuf,
>> vgasr_priv.delayed_switch_active = false;
>>
>> if (just_mux) {
>> - ret = vgasr_priv.handler->switchto(client_id);
>> + ret = vga_switchto(client_id);
>> goto out;
>> }
>>
>> --
>> 1.8.5.3
>>
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--
Jani Nikula, Intel Open Source Technology Center
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