Commit 9d5645ad authored by Noralf Trønnes's avatar Noralf Trønnes
Browse files

drm/tinydrm: Use drm_dev_enter/exit() 



This protects device resources from use after device removal.

There are 3 ways for driver-device unbinding to happen:
- The driver module is unloaded causing the driver to be unregistered.
  This can't happen as long as there are open file handles because a
  reference is taken on the module.
- The device is removed (Device Tree overlay unloading).
  This can happen at any time.
- The driver sysfs unbind file can be used to unbind the driver from the
  device. This can happen any time.

v2: Since drm_atomic_helper_shutdown() has to be called after
    drm_dev_unplug() we don't want do block ->disable after unplug.

Signed-off-by: default avatarNoralf Trønnes <noralf@tronnes.org>
Acked-by: default avatarGerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190225144232.20761-8-noralf@tronnes.org
parent 2afd9fcb

drivers/gpu/drm/tinydrm/hx8357d.c

+7 −2
Original line number Diff line number Diff line
@@ -50,13 +50,16 @@ static void yx240qv29_enable(struct drm_simple_display_pipe *pipe, 
{

	struct mipi_dbi *mipi = drm_to_mipi_dbi(pipe->crtc.dev);

	u8 addr_mode;

	int ret;

	int ret, idx;



	if (!drm_dev_enter(pipe->crtc.dev, &idx))

		return;



	DRM_DEBUG_KMS("\n");



	ret = mipi_dbi_poweron_conditional_reset(mipi);

	if (ret < 0)

		return;

		goto out_exit;

	if (ret == 1)

		goto out_enable;
@@ -172,6 +175,8 @@ out_enable: 
	}

	mipi_dbi_command(mipi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);

	mipi_dbi_enable_flush(mipi, crtc_state, plane_state);

out_exit:

	drm_dev_exit(idx);

}



static const struct drm_simple_display_pipe_funcs hx8357d_pipe_funcs = {

drivers/gpu/drm/tinydrm/ili9225.c

+20 −3
Original line number Diff line number Diff line
@@ -89,13 +89,16 @@ static void ili9225_fb_dirty(struct drm_framebuffer *fb, struct drm_rect *rect) 
	bool swap = mipi->swap_bytes;

	u16 x_start, y_start;

	u16 x1, x2, y1, y2;

	int ret = 0;

	int idx, ret = 0;

	bool full;

	void *tr;



	if (!mipi->enabled)

		return;



	if (!drm_dev_enter(fb->dev, &idx))

		return;



	full = width == fb->width && height == fb->height;



	DRM_DEBUG_KMS("Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect));
@@ -158,6 +161,8 @@ static void ili9225_fb_dirty(struct drm_framebuffer *fb, struct drm_rect *rect) 
err_msg:

	if (ret)

		dev_err_once(fb->dev->dev, "Failed to update display %d\n", ret);



	drm_dev_exit(idx);

}



static void ili9225_pipe_update(struct drm_simple_display_pipe *pipe,
@@ -191,9 +196,12 @@ static void ili9225_pipe_enable(struct drm_simple_display_pipe *pipe, 
		.y1 = 0,

		.y2 = fb->height,

	};

	int ret;

	int ret, idx;

	u8 am_id;



	if (!drm_dev_enter(pipe->crtc.dev, &idx))

		return;



	DRM_DEBUG_KMS("\n");



	mipi_dbi_hw_reset(mipi);
@@ -207,7 +215,7 @@ static void ili9225_pipe_enable(struct drm_simple_display_pipe *pipe, 
	ret = ili9225_command(mipi, ILI9225_POWER_CONTROL_1, 0x0000);

	if (ret) {

		DRM_DEV_ERROR(dev, "Error sending command %d\n", ret);

		return;

		goto out_exit;

	}

	ili9225_command(mipi, ILI9225_POWER_CONTROL_2, 0x0000);

	ili9225_command(mipi, ILI9225_POWER_CONTROL_3, 0x0000);
@@ -280,6 +288,8 @@ static void ili9225_pipe_enable(struct drm_simple_display_pipe *pipe, 


	mipi->enabled = true;

	ili9225_fb_dirty(fb, &rect);

out_exit:

	drm_dev_exit(idx);

}



static void ili9225_pipe_disable(struct drm_simple_display_pipe *pipe)
@@ -288,6 +298,13 @@ static void ili9225_pipe_disable(struct drm_simple_display_pipe *pipe) 


	DRM_DEBUG_KMS("\n");



	/*

	 * This callback is not protected by drm_dev_enter/exit since we want to

	 * turn off the display on regular driver unload. It's highly unlikely

	 * that the underlying SPI controller is gone should this be called after

	 * unplug.

	 */



	if (!mipi->enabled)

		return;

drivers/gpu/drm/tinydrm/ili9341.c

+7 −2
Original line number Diff line number Diff line
@@ -56,13 +56,16 @@ static void yx240qv29_enable(struct drm_simple_display_pipe *pipe, 
{

	struct mipi_dbi *mipi = drm_to_mipi_dbi(pipe->crtc.dev);

	u8 addr_mode;

	int ret;

	int ret, idx;



	if (!drm_dev_enter(pipe->crtc.dev, &idx))

		return;



	DRM_DEBUG_KMS("\n");



	ret = mipi_dbi_poweron_conditional_reset(mipi);

	if (ret < 0)

		return;

		goto out_exit;

	if (ret == 1)

		goto out_enable;
@@ -128,6 +131,8 @@ out_enable: 
	addr_mode |= ILI9341_MADCTL_BGR;

	mipi_dbi_command(mipi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);

	mipi_dbi_enable_flush(mipi, crtc_state, plane_state);

out_exit:

	drm_dev_exit(idx);

}



static const struct drm_simple_display_pipe_funcs ili9341_pipe_funcs = {

drivers/gpu/drm/tinydrm/mi0283qt.c

+7 −2
Original line number Diff line number Diff line
@@ -58,13 +58,16 @@ static void mi0283qt_enable(struct drm_simple_display_pipe *pipe, 
{

	struct mipi_dbi *mipi = drm_to_mipi_dbi(pipe->crtc.dev);

	u8 addr_mode;

	int ret;

	int ret, idx;



	if (!drm_dev_enter(pipe->crtc.dev, &idx))

		return;



	DRM_DEBUG_KMS("\n");



	ret = mipi_dbi_poweron_conditional_reset(mipi);

	if (ret < 0)

		return;

		goto out_exit;

	if (ret == 1)

		goto out_enable;
@@ -136,6 +139,8 @@ out_enable: 
	addr_mode |= ILI9341_MADCTL_BGR;

	mipi_dbi_command(mipi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);

	mipi_dbi_enable_flush(mipi, crtc_state, plane_state);

out_exit:

	drm_dev_exit(idx);

}



static const struct drm_simple_display_pipe_funcs mi0283qt_pipe_funcs = {

drivers/gpu/drm/tinydrm/mipi-dbi.c

+37 −5
Original line number Diff line number Diff line
@@ -220,13 +220,16 @@ static void mipi_dbi_fb_dirty(struct drm_framebuffer *fb, struct drm_rect *rect) 
	unsigned int height = rect->y2 - rect->y1;

	unsigned int width = rect->x2 - rect->x1;

	bool swap = mipi->swap_bytes;

	int ret = 0;

	int idx, ret = 0;

	bool full;

	void *tr;



	if (!mipi->enabled)

		return;



	if (!drm_dev_enter(fb->dev, &idx))

		return;



	full = width == fb->width && height == fb->height;



	DRM_DEBUG_KMS("Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect));
@@ -253,6 +256,8 @@ static void mipi_dbi_fb_dirty(struct drm_framebuffer *fb, struct drm_rect *rect) 
err_msg:

	if (ret)

		dev_err_once(fb->dev->dev, "Failed to update display %d\n", ret);



	drm_dev_exit(idx);

}



/**
@@ -307,10 +312,16 @@ void mipi_dbi_enable_flush(struct mipi_dbi *mipi, 
		.y1 = 0,

		.y2 = fb->height,

	};

	int idx;



	if (!drm_dev_enter(&mipi->drm, &idx))

		return;



	mipi->enabled = true;

	mipi_dbi_fb_dirty(fb, &rect);

	backlight_enable(mipi->backlight);



	drm_dev_exit(idx);

}

EXPORT_SYMBOL(mipi_dbi_enable_flush);
@@ -320,6 +331,10 @@ static void mipi_dbi_blank(struct mipi_dbi *mipi) 
	u16 height = drm->mode_config.min_height;

	u16 width = drm->mode_config.min_width;

	size_t len = width * height * 2;

	int idx;



	if (!drm_dev_enter(drm, &idx))

		return;



	memset(mipi->tx_buf, 0, len);
@@ -329,6 +344,8 @@ static void mipi_dbi_blank(struct mipi_dbi *mipi) 
			 (height >> 8) & 0xFF, (height - 1) & 0xFF);

	mipi_dbi_command_buf(mipi, MIPI_DCS_WRITE_MEMORY_START,

			     (u8 *)mipi->tx_buf, len);



	drm_dev_exit(idx);

}



/**
@@ -343,6 +360,9 @@ void mipi_dbi_pipe_disable(struct drm_simple_display_pipe *pipe) 
{

	struct mipi_dbi *mipi = drm_to_mipi_dbi(pipe->crtc.dev);



	if (!mipi->enabled)

		return;



	DRM_DEBUG_KMS("\n");



	mipi->enabled = false;
@@ -991,11 +1011,16 @@ static ssize_t mipi_dbi_debugfs_command_write(struct file *file, 
	u8 val, cmd = 0, parameters[64];

	char *buf, *pos, *token;

	unsigned int i;

	int ret;

	int ret, idx;



	if (!drm_dev_enter(&mipi->drm, &idx))

		return -ENODEV;



	buf = memdup_user_nul(ubuf, count);

	if (IS_ERR(buf))

		return PTR_ERR(buf);

	if (IS_ERR(buf)) {

		ret = PTR_ERR(buf);

		goto err_exit;

	}



	/* strip trailing whitespace */

	for (i = count - 1; i > 0; i--)
@@ -1031,6 +1056,8 @@ static ssize_t mipi_dbi_debugfs_command_write(struct file *file, 


err_free:

	kfree(buf);

err_exit:

	drm_dev_exit(idx);



	return ret < 0 ? ret : count;

}
@@ -1039,8 +1066,11 @@ static int mipi_dbi_debugfs_command_show(struct seq_file *m, void *unused) 
{

	struct mipi_dbi *mipi = m->private;

	u8 cmd, val[4];

	int ret, idx;

	size_t len;

	int ret;



	if (!drm_dev_enter(&mipi->drm, &idx))

		return -ENODEV;



	for (cmd = 0; cmd < 255; cmd++) {

		if (!mipi_dbi_command_is_read(mipi, cmd))
@@ -1071,6 +1101,8 @@ static int mipi_dbi_debugfs_command_show(struct seq_file *m, void *unused) 
		seq_printf(m, "%*phN\n", (int)len, val);

	}



	drm_dev_exit(idx);



	return 0;

}

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