alistair23-linux/drivers/gpu/drm/tegra/fb.c
Thierry Reding e2215321ff drm/tegra: Implement race-free hotplug detection
A race condition currently exists on Tegra, where it can happen that a
monitor attached via HDMI isn't detected during the initial FB helper
setup, but the hotplug event happens too early to be processed by the
poll helpers because they haven't been initialized yet. This happens
because on some boards the HDMI driver can control the regulator that
supplies the +5V pin on the HDMI connector. Therefore depending on the
timing between the initialization of the HDMI driver and the rest of
DRM, it's possible that the monitor returns the hotplug signal right
within the window where we would miss it.

Unfortunately, drm_kms_helper_poll_init() will wreak havoc when called
before at least some parts of the FB helpers have been set up.

This commit fixes this by splitting out the minimum of initialization
required to make drm_kms_helper_poll_init() work into a separate
function that can be called early. It is then safe to move all of the
poll helper initialization to an earlier point in time (before the
HDMI output driver has a chance to enable the +5V supply). That way if
the hotplug signal is returned before the initial FB helper setup, the
monitor will be forcefully detected at that point, and if the hotplug
signal is returned after that it will be properly handled by the poll
helpers.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2014-07-08 11:31:36 +10:00

416 lines
9.4 KiB
C

/*
* Copyright (C) 2012-2013 Avionic Design GmbH
* Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved.
*
* Based on the KMS/FB CMA helpers
* Copyright (C) 2012 Analog Device Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include "drm.h"
#include "gem.h"
static inline struct tegra_fb *to_tegra_fb(struct drm_framebuffer *fb)
{
return container_of(fb, struct tegra_fb, base);
}
#ifdef CONFIG_DRM_TEGRA_FBDEV
static inline struct tegra_fbdev *to_tegra_fbdev(struct drm_fb_helper *helper)
{
return container_of(helper, struct tegra_fbdev, base);
}
#endif
struct tegra_bo *tegra_fb_get_plane(struct drm_framebuffer *framebuffer,
unsigned int index)
{
struct tegra_fb *fb = to_tegra_fb(framebuffer);
if (index >= drm_format_num_planes(framebuffer->pixel_format))
return NULL;
return fb->planes[index];
}
bool tegra_fb_is_bottom_up(struct drm_framebuffer *framebuffer)
{
struct tegra_fb *fb = to_tegra_fb(framebuffer);
if (fb->planes[0]->flags & TEGRA_BO_BOTTOM_UP)
return true;
return false;
}
bool tegra_fb_is_tiled(struct drm_framebuffer *framebuffer)
{
struct tegra_fb *fb = to_tegra_fb(framebuffer);
if (fb->planes[0]->flags & TEGRA_BO_TILED)
return true;
return false;
}
static void tegra_fb_destroy(struct drm_framebuffer *framebuffer)
{
struct tegra_fb *fb = to_tegra_fb(framebuffer);
unsigned int i;
for (i = 0; i < fb->num_planes; i++) {
struct tegra_bo *bo = fb->planes[i];
if (bo)
drm_gem_object_unreference_unlocked(&bo->gem);
}
drm_framebuffer_cleanup(framebuffer);
kfree(fb->planes);
kfree(fb);
}
static int tegra_fb_create_handle(struct drm_framebuffer *framebuffer,
struct drm_file *file, unsigned int *handle)
{
struct tegra_fb *fb = to_tegra_fb(framebuffer);
return drm_gem_handle_create(file, &fb->planes[0]->gem, handle);
}
static struct drm_framebuffer_funcs tegra_fb_funcs = {
.destroy = tegra_fb_destroy,
.create_handle = tegra_fb_create_handle,
};
static struct tegra_fb *tegra_fb_alloc(struct drm_device *drm,
struct drm_mode_fb_cmd2 *mode_cmd,
struct tegra_bo **planes,
unsigned int num_planes)
{
struct tegra_fb *fb;
unsigned int i;
int err;
fb = kzalloc(sizeof(*fb), GFP_KERNEL);
if (!fb)
return ERR_PTR(-ENOMEM);
fb->planes = kzalloc(num_planes * sizeof(*planes), GFP_KERNEL);
if (!fb->planes) {
kfree(fb);
return ERR_PTR(-ENOMEM);
}
fb->num_planes = num_planes;
drm_helper_mode_fill_fb_struct(&fb->base, mode_cmd);
for (i = 0; i < fb->num_planes; i++)
fb->planes[i] = planes[i];
err = drm_framebuffer_init(drm, &fb->base, &tegra_fb_funcs);
if (err < 0) {
dev_err(drm->dev, "failed to initialize framebuffer: %d\n",
err);
kfree(fb->planes);
kfree(fb);
return ERR_PTR(err);
}
return fb;
}
static struct drm_framebuffer *tegra_fb_create(struct drm_device *drm,
struct drm_file *file,
struct drm_mode_fb_cmd2 *cmd)
{
unsigned int hsub, vsub, i;
struct tegra_bo *planes[4];
struct drm_gem_object *gem;
struct tegra_fb *fb;
int err;
hsub = drm_format_horz_chroma_subsampling(cmd->pixel_format);
vsub = drm_format_vert_chroma_subsampling(cmd->pixel_format);
for (i = 0; i < drm_format_num_planes(cmd->pixel_format); i++) {
unsigned int width = cmd->width / (i ? hsub : 1);
unsigned int height = cmd->height / (i ? vsub : 1);
unsigned int size, bpp;
gem = drm_gem_object_lookup(drm, file, cmd->handles[i]);
if (!gem) {
err = -ENXIO;
goto unreference;
}
bpp = drm_format_plane_cpp(cmd->pixel_format, i);
size = (height - 1) * cmd->pitches[i] +
width * bpp + cmd->offsets[i];
if (gem->size < size) {
err = -EINVAL;
goto unreference;
}
planes[i] = to_tegra_bo(gem);
}
fb = tegra_fb_alloc(drm, cmd, planes, i);
if (IS_ERR(fb)) {
err = PTR_ERR(fb);
goto unreference;
}
return &fb->base;
unreference:
while (i--)
drm_gem_object_unreference_unlocked(&planes[i]->gem);
return ERR_PTR(err);
}
#ifdef CONFIG_DRM_TEGRA_FBDEV
static struct fb_ops tegra_fb_ops = {
.owner = THIS_MODULE,
.fb_fillrect = sys_fillrect,
.fb_copyarea = sys_copyarea,
.fb_imageblit = sys_imageblit,
.fb_check_var = drm_fb_helper_check_var,
.fb_set_par = drm_fb_helper_set_par,
.fb_blank = drm_fb_helper_blank,
.fb_pan_display = drm_fb_helper_pan_display,
.fb_setcmap = drm_fb_helper_setcmap,
};
static int tegra_fbdev_probe(struct drm_fb_helper *helper,
struct drm_fb_helper_surface_size *sizes)
{
struct tegra_fbdev *fbdev = to_tegra_fbdev(helper);
struct drm_device *drm = helper->dev;
struct drm_mode_fb_cmd2 cmd = { 0 };
unsigned int bytes_per_pixel;
struct drm_framebuffer *fb;
unsigned long offset;
struct fb_info *info;
struct tegra_bo *bo;
size_t size;
int err;
bytes_per_pixel = DIV_ROUND_UP(sizes->surface_bpp, 8);
cmd.width = sizes->surface_width;
cmd.height = sizes->surface_height;
cmd.pitches[0] = sizes->surface_width * bytes_per_pixel;
cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
sizes->surface_depth);
size = cmd.pitches[0] * cmd.height;
bo = tegra_bo_create(drm, size, 0);
if (IS_ERR(bo))
return PTR_ERR(bo);
info = framebuffer_alloc(0, drm->dev);
if (!info) {
dev_err(drm->dev, "failed to allocate framebuffer info\n");
tegra_bo_free_object(&bo->gem);
return -ENOMEM;
}
fbdev->fb = tegra_fb_alloc(drm, &cmd, &bo, 1);
if (IS_ERR(fbdev->fb)) {
dev_err(drm->dev, "failed to allocate DRM framebuffer\n");
err = PTR_ERR(fbdev->fb);
goto release;
}
fb = &fbdev->fb->base;
helper->fb = fb;
helper->fbdev = info;
info->par = helper;
info->flags = FBINFO_FLAG_DEFAULT;
info->fbops = &tegra_fb_ops;
err = fb_alloc_cmap(&info->cmap, 256, 0);
if (err < 0) {
dev_err(drm->dev, "failed to allocate color map: %d\n", err);
goto destroy;
}
drm_fb_helper_fill_fix(info, fb->pitches[0], fb->depth);
drm_fb_helper_fill_var(info, helper, fb->width, fb->height);
offset = info->var.xoffset * bytes_per_pixel +
info->var.yoffset * fb->pitches[0];
drm->mode_config.fb_base = (resource_size_t)bo->paddr;
info->screen_base = (void __iomem *)bo->vaddr + offset;
info->screen_size = size;
info->fix.smem_start = (unsigned long)(bo->paddr + offset);
info->fix.smem_len = size;
return 0;
destroy:
drm_framebuffer_unregister_private(fb);
tegra_fb_destroy(fb);
release:
framebuffer_release(info);
return err;
}
static const struct drm_fb_helper_funcs tegra_fb_helper_funcs = {
.fb_probe = tegra_fbdev_probe,
};
static struct tegra_fbdev *tegra_fbdev_create(struct drm_device *drm)
{
struct tegra_fbdev *fbdev;
fbdev = kzalloc(sizeof(*fbdev), GFP_KERNEL);
if (!fbdev) {
dev_err(drm->dev, "failed to allocate DRM fbdev\n");
return ERR_PTR(-ENOMEM);
}
drm_fb_helper_prepare(drm, &fbdev->base, &tegra_fb_helper_funcs);
return fbdev;
}
static int tegra_fbdev_init(struct tegra_fbdev *fbdev,
unsigned int preferred_bpp,
unsigned int num_crtc,
unsigned int max_connectors)
{
struct drm_device *drm = fbdev->base.dev;
int err;
err = drm_fb_helper_init(drm, &fbdev->base, num_crtc, max_connectors);
if (err < 0) {
dev_err(drm->dev, "failed to initialize DRM FB helper\n");
return err;
}
err = drm_fb_helper_single_add_all_connectors(&fbdev->base);
if (err < 0) {
dev_err(drm->dev, "failed to add connectors\n");
goto fini;
}
err = drm_fb_helper_initial_config(&fbdev->base, preferred_bpp);
if (err < 0) {
dev_err(drm->dev, "failed to set initial configuration\n");
goto fini;
}
return 0;
fini:
drm_fb_helper_fini(&fbdev->base);
return err;
}
static void tegra_fbdev_free(struct tegra_fbdev *fbdev)
{
struct fb_info *info = fbdev->base.fbdev;
if (info) {
int err;
err = unregister_framebuffer(info);
if (err < 0)
DRM_DEBUG_KMS("failed to unregister framebuffer\n");
if (info->cmap.len)
fb_dealloc_cmap(&info->cmap);
framebuffer_release(info);
}
if (fbdev->fb) {
drm_framebuffer_unregister_private(&fbdev->fb->base);
tegra_fb_destroy(&fbdev->fb->base);
}
drm_fb_helper_fini(&fbdev->base);
kfree(fbdev);
}
void tegra_fbdev_restore_mode(struct tegra_fbdev *fbdev)
{
if (fbdev)
drm_fb_helper_restore_fbdev_mode_unlocked(&fbdev->base);
}
static void tegra_fb_output_poll_changed(struct drm_device *drm)
{
struct tegra_drm *tegra = drm->dev_private;
if (tegra->fbdev)
drm_fb_helper_hotplug_event(&tegra->fbdev->base);
}
#endif
static const struct drm_mode_config_funcs tegra_drm_mode_funcs = {
.fb_create = tegra_fb_create,
#ifdef CONFIG_DRM_TEGRA_FBDEV
.output_poll_changed = tegra_fb_output_poll_changed,
#endif
};
int tegra_drm_fb_prepare(struct drm_device *drm)
{
#ifdef CONFIG_DRM_TEGRA_FBDEV
struct tegra_drm *tegra = drm->dev_private;
#endif
drm->mode_config.min_width = 0;
drm->mode_config.min_height = 0;
drm->mode_config.max_width = 4096;
drm->mode_config.max_height = 4096;
drm->mode_config.funcs = &tegra_drm_mode_funcs;
#ifdef CONFIG_DRM_TEGRA_FBDEV
tegra->fbdev = tegra_fbdev_create(drm);
if (IS_ERR(tegra->fbdev))
return PTR_ERR(tegra->fbdev);
#endif
return 0;
}
int tegra_drm_fb_init(struct drm_device *drm)
{
#ifdef CONFIG_DRM_TEGRA_FBDEV
struct tegra_drm *tegra = drm->dev_private;
int err;
err = tegra_fbdev_init(tegra->fbdev, 32, drm->mode_config.num_crtc,
drm->mode_config.num_connector);
if (err < 0)
return err;
#endif
return 0;
}
void tegra_drm_fb_exit(struct drm_device *drm)
{
#ifdef CONFIG_DRM_TEGRA_FBDEV
struct tegra_drm *tegra = drm->dev_private;
tegra_fbdev_free(tegra->fbdev);
#endif
}