On Fri, Jan 26, 2018 at 02:17:04PM +0100, Thierry Escande wrote:
> From: "Kristian H. Kristensen" <hoegsb...@google.com>
>
> To improve PSR exit latency, we speculatively start exiting when we
> receive input events. Occasionally, this may lead to false positives,
> but most of the time we get a head start on coming out of PSR. Depending
> on how userspace takes to produce a new frame in response to the event,
> this can completely hide the exit latency. In case of Chrome OS, we
> typically get the input notifier 50ms or more before the dirty_fb
> triggered exit.
>
I think this is something that ideally would happen in userspace, since it has a
better idea of when to exit psr. IMO, this is something that should probably
stay in the CrOS tree.
Sean
> Signed-off-by: Kristian H. Kristensen <hoegsb...@google.com>
> Signed-off-by: Thierry Escande <thierry.esca...@collabora.com>
> ---
> drivers/gpu/drm/rockchip/rockchip_drm_psr.c | 134
> ++++++++++++++++++++++++++++
> 1 file changed, 134 insertions(+)
>
> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_psr.c
> b/drivers/gpu/drm/rockchip/rockchip_drm_psr.c
> index 9376f4396b6b..a107845ba97c 100644
> --- a/drivers/gpu/drm/rockchip/rockchip_drm_psr.c
> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_psr.c
> @@ -12,6 +12,8 @@
> * GNU General Public License for more details.
> */
>
> +#include <linux/input.h>
> +
> #include <drm/drmP.h>
> #include <drm/drm_crtc_helper.h>
>
> @@ -35,6 +37,9 @@ struct psr_drv {
> enum psr_state state;
>
> struct delayed_work flush_work;
> + struct work_struct disable_work;
> +
> + struct input_handler input_handler;
>
> int (*set)(struct drm_encoder *encoder, bool enable);
> };
> @@ -133,6 +138,18 @@ static void psr_flush_handler(struct work_struct *work)
> mutex_unlock(&psr->lock);
> }
>
> +static void psr_disable_handler(struct work_struct *work)
> +{
> + struct psr_drv *psr = container_of(work, struct psr_drv, disable_work);
> +
> + /* If the state has changed since we initiated the flush, do nothing */
> + mutex_lock(&psr->lock);
> + if (psr->state == PSR_ENABLE)
> + psr_set_state_locked(psr, PSR_FLUSH);
> + mutex_unlock(&psr->lock);
> + mod_delayed_work(system_wq, &psr->flush_work, PSR_FLUSH_TIMEOUT_MS);
> +}
> +
> /**
> * rockchip_drm_psr_activate - activate PSR on the given pipe
> * @encoder: encoder to obtain the PSR encoder
> @@ -173,6 +190,7 @@ int rockchip_drm_psr_deactivate(struct drm_encoder
> *encoder)
> psr->active = false;
> mutex_unlock(&psr->lock);
> cancel_delayed_work_sync(&psr->flush_work);
> + cancel_work_sync(&psr->disable_work);
>
> return 0;
> }
> @@ -226,6 +244,95 @@ void rockchip_drm_psr_flush_all(struct drm_device *dev)
> }
> EXPORT_SYMBOL(rockchip_drm_psr_flush_all);
>
> +static void psr_input_event(struct input_handle *handle,
> + unsigned int type, unsigned int code,
> + int value)
> +{
> + struct psr_drv *psr = handle->handler->private;
> +
> + schedule_work(&psr->disable_work);
> +}
> +
> +static int psr_input_connect(struct input_handler *handler,
> + struct input_dev *dev,
> + const struct input_device_id *id)
> +{
> + struct input_handle *handle;
> + int error;
> +
> + handle = kzalloc(sizeof(struct input_handle), GFP_KERNEL);
> + if (!handle)
> + return -ENOMEM;
> +
> + handle->dev = dev;
> + handle->handler = handler;
> + handle->name = "rockchip-psr";
> +
> + error = input_register_handle(handle);
> + if (error)
> + goto err2;
> +
> + error = input_open_device(handle);
> + if (error)
> + goto err1;
> +
> + return 0;
> +
> +err1:
> + input_unregister_handle(handle);
> +err2:
> + kfree(handle);
> + return error;
> +}
> +
> +static void psr_input_disconnect(struct input_handle *handle)
> +{
> + input_close_device(handle);
> + input_unregister_handle(handle);
> + kfree(handle);
> +}
> +
> +/* Same device ids as cpu-boost */
> +static const struct input_device_id psr_ids[] = {
> + {
> + .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
> + INPUT_DEVICE_ID_MATCH_ABSBIT,
> + .evbit = { BIT_MASK(EV_ABS) },
> + .absbit = { [BIT_WORD(ABS_MT_POSITION_X)] =
> + BIT_MASK(ABS_MT_POSITION_X) |
> + BIT_MASK(ABS_MT_POSITION_Y) },
> + }, /* multi-touch touchscreen */
> + {
> + .flags = INPUT_DEVICE_ID_MATCH_EVBIT,
> + .evbit = { BIT_MASK(EV_ABS) },
> + .absbit = { [BIT_WORD(ABS_X)] = BIT_MASK(ABS_X) }
> +
> + }, /* stylus or joystick device */
> + {
> + .flags = INPUT_DEVICE_ID_MATCH_EVBIT,
> + .evbit = { BIT_MASK(EV_KEY) },
> + .keybit = { [BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) },
> + }, /* pointer (e.g. trackpad, mouse) */
> + {
> + .flags = INPUT_DEVICE_ID_MATCH_EVBIT,
> + .evbit = { BIT_MASK(EV_KEY) },
> + .keybit = { [BIT_WORD(KEY_ESC)] = BIT_MASK(KEY_ESC) },
> + }, /* keyboard */
> + {
> + .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
> + INPUT_DEVICE_ID_MATCH_KEYBIT,
> + .evbit = { BIT_MASK(EV_KEY) },
> + .keybit = {[BIT_WORD(BTN_JOYSTICK)] = BIT_MASK(BTN_JOYSTICK) },
> + }, /* joysticks not caught by ABS_X above */
> + {
> + .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
> + INPUT_DEVICE_ID_MATCH_KEYBIT,
> + .evbit = { BIT_MASK(EV_KEY) },
> + .keybit = { [BIT_WORD(BTN_GAMEPAD)] = BIT_MASK(BTN_GAMEPAD) },
> + }, /* gamepad */
> + { },
> +};
> +
> /**
> * rockchip_drm_psr_register - register encoder to psr driver
> * @encoder: encoder that obtain the PSR function
> @@ -239,6 +346,7 @@ int rockchip_drm_psr_register(struct drm_encoder *encoder,
> {
> struct rockchip_drm_private *drm_drv = encoder->dev->dev_private;
> struct psr_drv *psr;
> + int error;
>
> if (!encoder || !psr_set)
> return -EINVAL;
> @@ -248,6 +356,7 @@ int rockchip_drm_psr_register(struct drm_encoder *encoder,
> return -ENOMEM;
>
> INIT_DELAYED_WORK(&psr->flush_work, psr_flush_handler);
> + INIT_WORK(&psr->disable_work, psr_disable_handler);
> mutex_init(&psr->lock);
>
> psr->active = true;
> @@ -255,11 +364,33 @@ int rockchip_drm_psr_register(struct drm_encoder
> *encoder,
> psr->encoder = encoder;
> psr->set = psr_set;
>
> + psr->input_handler.event = psr_input_event;
> + psr->input_handler.connect = psr_input_connect;
> + psr->input_handler.disconnect = psr_input_disconnect;
> + psr->input_handler.name =
> + kasprintf(GFP_KERNEL, "rockchip-psr-%s", encoder->name);
> + if (!psr->input_handler.name) {
> + error = -ENOMEM;
> + goto err2;
> + }
> + psr->input_handler.id_table = psr_ids;
> + psr->input_handler.private = psr;
> +
> + error = input_register_handler(&psr->input_handler);
> + if (error)
> + goto err1;
> +
> mutex_lock(&drm_drv->psr_list_lock);
> list_add_tail(&psr->list, &drm_drv->psr_list);
> mutex_unlock(&drm_drv->psr_list_lock);
>
> return 0;
> +
> + err1:
> + kfree(psr->input_handler.name);
> + err2:
> + kfree(psr);
> + return error;
> }
> EXPORT_SYMBOL(rockchip_drm_psr_register);
>
> @@ -279,8 +410,11 @@ void rockchip_drm_psr_unregister(struct drm_encoder
> *encoder)
> mutex_lock(&drm_drv->psr_list_lock);
> list_for_each_entry_safe(psr, n, &drm_drv->psr_list, list) {
> if (psr->encoder == encoder) {
> + input_unregister_handler(&psr->input_handler);
> cancel_delayed_work_sync(&psr->flush_work);
> + cancel_work_sync(&psr->disable_work);
> list_del(&psr->list);
> + kfree(psr->input_handler.name);
> kfree(psr);
> }
> }
> --
> 2.14.1
>
--
Sean Paul, Software Engineer, Google / Chromium OS
