[Intel-gfx] [RFC v4 12/25] drm/i915: Add drm_driver->initial_client_display callback

Noralf Trønnes noralf at tronnes.org
Fri Mar 1 11:46:19 UTC 2019



Den 16.04.2018 10.38, skrev Daniel Vetter:
> On Sat, Apr 14, 2018 at 01:53:05PM +0200, Noralf Trønnes wrote:
>> As part of moving the modesetting code out of drm_fb_helper and into
>> drm_client, the drm_fb_helper_funcs->initial_config callback needs to go.
>> Replace it with a drm_driver->initial_client_display callback that can
>> work for all in-kernel clients.
>>
>> TODO:
>> - Add a patch that moves the function out of intel_fbdev.c since it's not
>>   fbdev specific anymore.
>>
>> Signed-off-by: Noralf Trønnes <noralf at tronnes.org>
> 
> So the reason we originally added this callback for i915 fast boot was
> that there wasn't any atomic around yet. And it was all an experiment to
> figure out how to best go about designing fastboot.
> 
> But now we have fbdev, and fastboot design is also pretty clear:
> 
> 1. driver loads
> 2. driver reads out current hw state, reconstructs a full atomic state for
> everything and stuffs it into connector/crtc/plane->state pointers.
> 3. fbdev and any other client read out current state (with some caveats)
> and just take it over.
> 
> What non-fastboot drivers do:
> 1. drivers load
> 2. reset both hw and sw state to everything off.
> 
> Now the intel_fb_initial_config is all generic code really, and it will
> neatly fall back to the default config if everything is off. This means we
> could:
> 1. Move the intel_fb_initial_config into the fbdev helpers.
> 2. Nuke the ->initial_config callback.
> 
> And pronto! every driver which implements hw state readout will get fbdev
> fastboot for free.
> 

I'm back working on this now and there's one intel specific thing:
num_pipes, in that function that I don't know how to handle when moving
the code into the fbdev helper:

static bool intel_fb_initial_config(...)
{
[...]
	/*
	 * If the BIOS didn't enable everything it could, fall back to have the
	 * same user experiencing of lighting up as much as possible like the
	 * fbdev helper library.
	 */
	if (num_connectors_enabled != num_connectors_detected &&
	    num_connectors_enabled < INTEL_INFO(dev_priv)->num_pipes) {
		DRM_DEBUG_KMS("fallback: Not all outputs enabled\n");
		DRM_DEBUG_KMS("Enabled: %i, detected: %i\n", num_connectors_enabled,
			      num_connectors_detected);
		fallback = true;
	}

Noralf.

> And since you've already rewritting the intel code to use drm_client, it's
> practically done already. Just need to s/intel_/drm_fbdev_helper_ or
> something like that :-)
> -Daniel
> 
>> ---
>>  drivers/gpu/drm/drm_fb_helper.c    |  19 +++++--
>>  drivers/gpu/drm/i915/i915_drv.c    |   1 +
>>  drivers/gpu/drm/i915/intel_drv.h   |  11 ++++
>>  drivers/gpu/drm/i915/intel_fbdev.c | 113 ++++++++++++++++++-------------------
>>  include/drm/drm_drv.h              |  21 +++++++
>>  5 files changed, 104 insertions(+), 61 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
>> index b992f59dad30..5407bf6dc8c0 100644
>> --- a/drivers/gpu/drm/drm_fb_helper.c
>> +++ b/drivers/gpu/drm/drm_fb_helper.c
>> @@ -2103,6 +2103,20 @@ static void drm_setup_crtcs(struct drm_fb_helper *fb_helper,
>>  	/* prevent concurrent modification of connector_count by hotplug */
>>  	lockdep_assert_held(&fb_helper->lock);
>>  
>> +	mutex_lock(&dev->mode_config.mutex);
>> +	if (drm_fb_helper_probe_connector_modes(fb_helper, width, height) == 0)
>> +		DRM_DEBUG_KMS("No connectors reported connected with modes\n");
>> +
>> +	if (dev->driver->initial_client_display) {
>> +		display = dev->driver->initial_client_display(dev, width, height);
>> +		if (display) {
>> +			drm_client_display_free(fb_helper->display);
>> +			fb_helper->display = display;
>> +			mutex_unlock(&dev->mode_config.mutex);
>> +			return;
>> +		}
>> +	}
>> +
>>  	crtcs = kcalloc(fb_helper->connector_count,
>>  			sizeof(struct drm_fb_helper_crtc *), GFP_KERNEL);
>>  	modes = kcalloc(fb_helper->connector_count,
>> @@ -2120,9 +2134,6 @@ static void drm_setup_crtcs(struct drm_fb_helper *fb_helper,
>>  	if (IS_ERR(display))
>>  		goto out;
>>  
>> -	mutex_lock(&fb_helper->dev->mode_config.mutex);
>> -	if (drm_fb_helper_probe_connector_modes(fb_helper, width, height) == 0)
>> -		DRM_DEBUG_KMS("No connectors reported connected with modes\n");
>>  	drm_enable_connectors(fb_helper, enabled);
>>  
>>  	if (!(fb_helper->funcs->initial_config &&
>> @@ -2144,7 +2155,6 @@ static void drm_setup_crtcs(struct drm_fb_helper *fb_helper,
>>  
>>  		drm_pick_crtcs(fb_helper, crtcs, modes, 0, width, height);
>>  	}
>> -	mutex_unlock(&fb_helper->dev->mode_config.mutex);
>>  
>>  	/* need to set the modesets up here for use later */
>>  	/* fill out the connector<->crtc mappings into the modesets */
>> @@ -2182,6 +2192,7 @@ static void drm_setup_crtcs(struct drm_fb_helper *fb_helper,
>>  	drm_client_display_free(fb_helper->display);
>>  	fb_helper->display = display;
>>  out:
>> +	mutex_unlock(&dev->mode_config.mutex);
>>  	kfree(crtcs);
>>  	kfree(modes);
>>  	kfree(offsets);
>> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
>> index 07c07d55398b..b746c0cbaa4b 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.c
>> +++ b/drivers/gpu/drm/i915/i915_drv.c
>> @@ -2857,6 +2857,7 @@ static struct drm_driver driver = {
>>  
>>  	.dumb_create = i915_gem_dumb_create,
>>  	.dumb_map_offset = i915_gem_mmap_gtt,
>> +	.initial_client_display = i915_initial_client_display,
>>  	.ioctls = i915_ioctls,
>>  	.num_ioctls = ARRAY_SIZE(i915_ioctls),
>>  	.fops = &i915_driver_fops,
>> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
>> index d4368589b355..f77f510617c5 100644
>> --- a/drivers/gpu/drm/i915/intel_drv.h
>> +++ b/drivers/gpu/drm/i915/intel_drv.h
>> @@ -1720,6 +1720,9 @@ extern void intel_fbdev_fini(struct drm_i915_private *dev_priv);
>>  extern void intel_fbdev_set_suspend(struct drm_device *dev, int state, bool synchronous);
>>  extern void intel_fbdev_output_poll_changed(struct drm_device *dev);
>>  extern void intel_fbdev_restore_mode(struct drm_device *dev);
>> +struct drm_client_display *
>> +i915_initial_client_display(struct drm_device *dev, unsigned int width,
>> +			    unsigned int height);
>>  #else
>>  static inline int intel_fbdev_init(struct drm_device *dev)
>>  {
>> @@ -1749,6 +1752,14 @@ static inline void intel_fbdev_output_poll_changed(struct drm_device *dev)
>>  static inline void intel_fbdev_restore_mode(struct drm_device *dev)
>>  {
>>  }
>> +
>> +static inline struct drm_client_display *
>> +i915_initial_client_display(struct drm_device *dev, unsigned int width,
>> +			    unsigned int height)
>> +{
>> +	return NULL;
>> +}
>> +
>>  #endif
>>  
>>  /* intel_fbc.c */
>> diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c
>> index a4ab8575a72e..b7f44c9475a8 100644
>> --- a/drivers/gpu/drm/i915/intel_fbdev.c
>> +++ b/drivers/gpu/drm/i915/intel_fbdev.c
>> @@ -38,6 +38,7 @@
>>  #include <linux/vga_switcheroo.h>
>>  
>>  #include <drm/drmP.h>
>> +#include <drm/drm_client.h>
>>  #include <drm/drm_crtc.h>
>>  #include <drm/drm_fb_helper.h>
>>  #include "intel_drv.h"
>> @@ -287,18 +288,6 @@ static int intelfb_create(struct drm_fb_helper *helper,
>>  	return ret;
>>  }
>>  
>> -static struct drm_fb_helper_crtc *
>> -intel_fb_helper_crtc(struct drm_fb_helper *fb_helper, struct drm_crtc *crtc)
>> -{
>> -	int i;
>> -
>> -	for (i = 0; i < fb_helper->crtc_count; i++)
>> -		if (fb_helper->crtc_info[i].mode_set.crtc == crtc)
>> -			return &fb_helper->crtc_info[i];
>> -
>> -	return NULL;
>> -}
>> -
>>  /*
>>   * Try to read the BIOS display configuration and use it for the initial
>>   * fb configuration.
>> @@ -326,44 +315,48 @@ intel_fb_helper_crtc(struct drm_fb_helper *fb_helper, struct drm_crtc *crtc)
>>   * is in VGA mode we need to recalculate watermarks and set a new high-res
>>   * framebuffer anyway.
>>   */
>> -static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
>> -				    struct drm_fb_helper_crtc **crtcs,
>> -				    struct drm_display_mode **modes,
>> -				    struct drm_fb_offset *offsets,
>> -				    bool *enabled, int width, int height)
>> +struct drm_client_display *
>> +i915_initial_client_display(struct drm_device *dev, unsigned int width,
>> +			    unsigned int height)
>>  {
>> -	struct drm_i915_private *dev_priv = to_i915(fb_helper->dev);
>> +	struct drm_i915_private *dev_priv = to_i915(dev);
>>  	unsigned long conn_configured, conn_seq, mask;
>> -	unsigned int count = min(fb_helper->connector_count, BITS_PER_LONG);
>> -	int i, j;
>> -	bool *save_enabled;
>> -	bool fallback = true, ret = true;
>> +	bool fallback = true, *enabled = NULL;
>> +	struct drm_client_display *display;
>> +	struct drm_connector **connectors;
>> +	int i, connector_count;
>> +	unsigned int count;
>>  	int num_connectors_enabled = 0;
>>  	int num_connectors_detected = 0;
>>  	struct drm_modeset_acquire_ctx ctx;
>>  
>> -	save_enabled = kcalloc(count, sizeof(bool), GFP_KERNEL);
>> -	if (!save_enabled)
>> -		return false;
>> +	display = drm_client_display_create(dev);
>> +	if (IS_ERR(display))
>> +		return NULL;
>>  
>>  	drm_modeset_acquire_init(&ctx, 0);
>>  
>> -	while (drm_modeset_lock_all_ctx(fb_helper->dev, &ctx) != 0)
>> +	while (drm_modeset_lock_all_ctx(dev, &ctx) != 0)
>>  		drm_modeset_backoff(&ctx);
>>  
>> -	memcpy(save_enabled, enabled, count);
>> +	connector_count = drm_connector_get_all(dev, &connectors);
>> +	if (connector_count < 1)
>> +		goto bail;
>> +
>> +	enabled = drm_connector_get_enabled_status(connectors, connector_count);
>> +	if (!enabled)
>> +		goto bail;
>> +
>> +	count = min(connector_count, BITS_PER_LONG);
>>  	mask = GENMASK(count - 1, 0);
>>  	conn_configured = 0;
>>  retry:
>>  	conn_seq = conn_configured;
>>  	for (i = 0; i < count; i++) {
>> -		struct drm_fb_helper_connector *fb_conn;
>> -		struct drm_connector *connector;
>> +		struct drm_connector *connector = connectors[i];
>> +		struct drm_display_mode *mode;
>> +		struct drm_mode_set *modeset;
>>  		struct drm_encoder *encoder;
>> -		struct drm_fb_helper_crtc *new_crtc;
>> -
>> -		fb_conn = fb_helper->connector_info[i];
>> -		connector = fb_conn->connector;
>>  
>>  		if (conn_configured & BIT(i))
>>  			continue;
>> @@ -402,16 +395,13 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
>>  
>>  		num_connectors_enabled++;
>>  
>> -		new_crtc = intel_fb_helper_crtc(fb_helper,
>> -						connector->state->crtc);
>> -
>>  		/*
>>  		 * Make sure we're not trying to drive multiple connectors
>>  		 * with a single CRTC, since our cloning support may not
>>  		 * match the BIOS.
>>  		 */
>> -		for (j = 0; j < count; j++) {
>> -			if (crtcs[j] == new_crtc) {
>> +		drm_client_display_for_each_modeset(modeset, display) {
>> +			if (modeset->connectors[0] == connector) {
>>  				DRM_DEBUG_KMS("fallback: cloned configuration\n");
>>  				goto bail;
>>  			}
>> @@ -421,28 +411,26 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
>>  			      connector->name);
>>  
>>  		/* go for command line mode first */
>> -		modes[i] = drm_connector_pick_cmdline_mode(connector);
>> +		mode = drm_connector_pick_cmdline_mode(connector);
>>  
>>  		/* try for preferred next */
>> -		if (!modes[i]) {
>> +		if (!mode) {
>>  			DRM_DEBUG_KMS("looking for preferred mode on connector %s %d\n",
>>  				      connector->name, connector->has_tile);
>> -			modes[i] = drm_connector_has_preferred_mode(connector,
>> -								    width,
>> -								    height);
>> +			mode = drm_connector_has_preferred_mode(connector,
>> +								width, height);
>>  		}
>>  
>>  		/* No preferred mode marked by the EDID? Are there any modes? */
>> -		if (!modes[i] && !list_empty(&connector->modes)) {
>> +		if (!mode && !list_empty(&connector->modes)) {
>>  			DRM_DEBUG_KMS("using first mode listed on connector %s\n",
>>  				      connector->name);
>> -			modes[i] = list_first_entry(&connector->modes,
>> -						    struct drm_display_mode,
>> -						    head);
>> +			mode = list_first_entry(&connector->modes,
>> +						struct drm_display_mode, head);
>>  		}
>>  
>>  		/* last resort: use current mode */
>> -		if (!modes[i]) {
>> +		if (!mode) {
>>  			/*
>>  			 * IMPORTANT: We want to use the adjusted mode (i.e.
>>  			 * after the panel fitter upscaling) as the initial
>> @@ -458,16 +446,26 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
>>  			 */
>>  			DRM_DEBUG_KMS("looking for current mode on connector %s\n",
>>  				      connector->name);
>> -			modes[i] = &connector->state->crtc->mode;
>> +			mode = &connector->state->crtc->mode;
>>  		}
>> -		crtcs[i] = new_crtc;
>> +
>> +		modeset = drm_client_display_find_modeset(display, connector->state->crtc);
>> +		if (WARN_ON(!modeset))
>> +			goto bail;
>> +
>> +		modeset->mode = drm_mode_duplicate(dev, mode);
>> +		drm_connector_get(connector);
>> +		modeset->connectors[0] = connector;
>> +		modeset->num_connectors = 1;
>> +		modeset->x = 0;
>> +		modeset->y = 0;
>>  
>>  		DRM_DEBUG_KMS("connector %s on [CRTC:%d:%s]: %dx%d%s\n",
>>  			      connector->name,
>>  			      connector->state->crtc->base.id,
>>  			      connector->state->crtc->name,
>> -			      modes[i]->hdisplay, modes[i]->vdisplay,
>> -			      modes[i]->flags & DRM_MODE_FLAG_INTERLACE ? "i" :"");
>> +			      mode->hdisplay, mode->vdisplay,
>> +			      mode->flags & DRM_MODE_FLAG_INTERLACE ? "i" : "");
>>  
>>  		fallback = false;
>>  		conn_configured |= BIT(i);
>> @@ -492,19 +490,20 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
>>  	if (fallback) {
>>  bail:
>>  		DRM_DEBUG_KMS("Not using firmware configuration\n");
>> -		memcpy(enabled, save_enabled, count);
>> -		ret = false;
>> +		drm_client_display_free(display);
>> +		display = NULL;
>>  	}
>>  
>>  	drm_modeset_drop_locks(&ctx);
>>  	drm_modeset_acquire_fini(&ctx);
>>  
>> -	kfree(save_enabled);
>> -	return ret;
>> +	drm_connector_put_all(connectors, connector_count);
>> +	kfree(enabled);
>> +
>> +	return display;
>>  }
>>  
>>  static const struct drm_fb_helper_funcs intel_fb_helper_funcs = {
>> -	.initial_config = intel_fb_initial_config,
>>  	.fb_probe = intelfb_create,
>>  };
>>  
>> diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
>> index 7e545f5f94d3..13356e6fd40c 100644
>> --- a/include/drm/drm_drv.h
>> +++ b/include/drm/drm_drv.h
>> @@ -32,6 +32,7 @@
>>  
>>  #include <drm/drm_device.h>
>>  
>> +struct drm_client_display;
>>  struct drm_file;
>>  struct drm_gem_object;
>>  struct drm_master;
>> @@ -553,6 +554,26 @@ struct drm_driver {
>>  			    struct drm_device *dev,
>>  			    uint32_t handle);
>>  
>> +	/**
>> +	 * @initial_client_config:
>> +	 *
>> +	 * Driver callback to setup an initial fbdev display configuration.
>> +	 * Drivers can use this callback to tell the fbdev emulation what the
>> +	 * preferred initial configuration is. This is useful to implement
>> +	 * smooth booting where the fbdev (and subsequently all userspace) never
>> +	 * changes the mode, but always inherits the existing configuration.
>> +	 *
>> +	 * This callback is optional.
>> +	 *
>> +	 * RETURNS:
>> +	 *
>> +	 * The driver should return true if a suitable initial configuration has
>> +	 * been filled out and false when the fbdev helper should fall back to
>> +	 * the default probing logic.
>> +	 */
>> +	struct drm_client_display *(*initial_client_display)(struct drm_device *dev,
>> +					unsigned int width, unsigned int height);
>> +
>>  	/**
>>  	 * @gem_vm_ops: Driver private ops for this object
>>  	 */
>> -- 
>> 2.15.1
>>
>> _______________________________________________
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>> Intel-gfx at lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 


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