linux/drivers/media/platform/vsp1/vsp1_dl.h
Laurent Pinchart a0991c71ea v4l: vsp1: Don't recycle active list at display start
When the display start interrupt occurs, we know that the hardware has
finished loading the active display list. The driver then proceeds to
recycle the list, assuming it won't be needed anymore.

This assumption holds true for headerless display lists, as the VSP
doesn't reload the list for the next frame if it hasn't changed.
However, this isn't true anymore for header display lists, as they are
loaded at every frame start regardless of whether they have been
updated.

To prepare for header display lists usage in display pipelines, we need
to postpone recycling the list until it gets replaced by a new one
through a page flip. The driver already does so in the frame end
interrupt handler, so all we need is to skip list recycling in the
display start interrupt handler.

While the active list can be recycled at display start for headerless
display lists, there's no real harm in postponing that to the frame end
interrupt handler in all cases. This simplifies interrupt handling as we
don't need to process the display start interrupt anymore.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Acked-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-07-29 23:46:56 +03:00

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1.5 KiB
C

/*
* vsp1_dl.h -- R-Car VSP1 Display List
*
* Copyright (C) 2015 Renesas Corporation
*
* Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#ifndef __VSP1_DL_H__
#define __VSP1_DL_H__
#include <linux/types.h>
struct vsp1_device;
struct vsp1_dl_fragment;
struct vsp1_dl_list;
struct vsp1_dl_manager;
void vsp1_dlm_setup(struct vsp1_device *vsp1);
struct vsp1_dl_manager *vsp1_dlm_create(struct vsp1_device *vsp1,
unsigned int index,
unsigned int prealloc);
void vsp1_dlm_destroy(struct vsp1_dl_manager *dlm);
void vsp1_dlm_reset(struct vsp1_dl_manager *dlm);
bool vsp1_dlm_irq_frame_end(struct vsp1_dl_manager *dlm);
struct vsp1_dl_list *vsp1_dl_list_get(struct vsp1_dl_manager *dlm);
void vsp1_dl_list_put(struct vsp1_dl_list *dl);
void vsp1_dl_list_write(struct vsp1_dl_list *dl, u32 reg, u32 data);
void vsp1_dl_list_commit(struct vsp1_dl_list *dl);
struct vsp1_dl_body *vsp1_dl_fragment_alloc(struct vsp1_device *vsp1,
unsigned int num_entries);
void vsp1_dl_fragment_free(struct vsp1_dl_body *dlb);
void vsp1_dl_fragment_write(struct vsp1_dl_body *dlb, u32 reg, u32 data);
int vsp1_dl_list_add_fragment(struct vsp1_dl_list *dl,
struct vsp1_dl_body *dlb);
int vsp1_dl_list_add_chain(struct vsp1_dl_list *head, struct vsp1_dl_list *dl);
#endif /* __VSP1_DL_H__ */