Re: [PATCH 1/2] drm/mxsfb: Fix runtime PM for unpowering lcdif block

On 05.06.2018 19:11, Leonard Crestez wrote:

Adding imx6sl/sx lcdif nodes in a power domain currently does work, it results in black/corrupted screens or hangs. While the driver does enable runtime pm it does not deal correctly with the block being unpowered.

Fix by adding pm_runtime_get/put_sync to mxsfb_pipe_enable/disable.

The mxsfb_plane_atomic_update function can get called before mxsfb_pipe_enable while the block is not powered. When this happens the write to LCDIF_NEXT_BUF is lost causing random corrupted pixels on unblank.

Fix this by splitting the writing of gem->paddr to nextbuf into a mxsfb_update_hw_next_buf functiona and also calling it from mxsfb_crtc_mode_set_nofb.

Also add fields to mxsfb_drv to keep track of enabled/suspended states.

Signed-off-by: Robert Chiras robert.chiras@nxp.com Signed-off-by: Leonard Crestez leonard.crestez@nxp.com

That patch seems to go in the right direction.

One comment below.

---

drivers/gpu/drm/mxsfb/mxsfb_crtc.c | 38 +++++++++++----- drivers/gpu/drm/mxsfb/mxsfb_drv.c | 72 +++++++++++++++++++++++++++++- drivers/gpu/drm/mxsfb/mxsfb_drv.h | 3 ++ 3 files changed, 100 insertions(+), 13 deletions(-)

This was initially written by Robert for imx8m but I tested it also works on imx6sx/imx6sl to DISPMIX power domain.

Tested on imx6sl-evk and imx6sx-sdb with SEIKO 43WVF1G panel by blanking and unblanking via sysfs and suspend/resume

Testing requires a modified config (to enable MXFSB_DRM): CONFIG_DRM_MXSFB=y CONFIG_DRM_PANEL_SEIKO_43WVF1G=y CONFIG_FB_MXS=n

It also requires dts changes to enable the DISPMIX power domain. The dts changes might break drivers so this patch attempts to fix the lcdif driver first.

Patch 2 is a RFC of imx6sl changes, imx6sx is a bit more complicated and it also interacts with PCI.

diff --git a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c index 0abe77675b76..cce2ec1c80ae 100644 --- a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c +++ b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c @@ -194,10 +194,25 @@ static int mxsfb_reset_block(void __iomem *reset_addr) return ret;

return clear_poll_bit(reset_addr, MODULE_CLKGATE); }

+static void mxsfb_update_hw_next_buf(struct mxsfb_drm_private *mxsfb) +{

• struct drm_framebuffer *fb = mxsfb->pipe.plane.state->fb;
• struct drm_gem_cma_object *gem;
• if (!fb)

• return;
  

• gem = drm_fb_cma_get_gem_obj(fb, 0);
• if (!gem)

• return;
  

• writel(gem->paddr, mxsfb->base + mxsfb->devdata->next_buf);

+}

static void mxsfb_crtc_mode_set_nofb(struct mxsfb_drm_private *mxsfb) { struct drm_display_mode *m = &mxsfb->pipe.crtc.state->adjusted_mode; const u32 bus_flags = mxsfb->connector.display_info.bus_flags; u32 vdctrl0, vsync_pulse_len, hsync_pulse_len; @@ -268,35 +283,41 @@ static void mxsfb_crtc_mode_set_nofb(struct mxsfb_drm_private *mxsfb) mxsfb->base + LCDC_VDCTRL3);

writel(SET_DOTCLK_H_VALID_DATA_CNT(m->hdisplay), mxsfb->base + LCDC_VDCTRL4);

• mxsfb_update_hw_next_buf(mxsfb); mxsfb_disable_axi_clk(mxsfb);

}

void mxsfb_crtc_enable(struct mxsfb_drm_private *mxsfb) {

• if (mxsfb->enabled)

• return;
  

• mxsfb_crtc_mode_set_nofb(mxsfb); mxsfb_enable_controller(mxsfb);
• mxsfb->enabled = true;

Is this state keeping really necessary?

-- Stefan

}

void mxsfb_crtc_disable(struct mxsfb_drm_private *mxsfb) {

• if (!mxsfb->enabled)

• return;
  

• mxsfb_disable_controller(mxsfb);
• mxsfb->enabled = false;

}

void mxsfb_plane_atomic_update(struct mxsfb_drm_private *mxsfb, struct drm_plane_state *state) { struct drm_simple_display_pipe *pipe = &mxsfb->pipe; struct drm_crtc *crtc = &pipe->crtc;

• struct drm_framebuffer *fb = pipe->plane.state->fb; struct drm_pending_vblank_event *event;

• struct drm_gem_cma_object *gem;

• if (!crtc)

• return;
  
  

  spin_lock_irq(&crtc->dev->event_lock); event = crtc->state->event; if (event) { crtc->state->event = NULL;

@@ -307,14 +328,9 @@ void mxsfb_plane_atomic_update(struct mxsfb_drm_private *mxsfb, drm_crtc_send_vblank_event(crtc, event); } } spin_unlock_irq(&crtc->dev->event_lock);

• if (!fb)

• return;
  

• gem = drm_fb_cma_get_gem_obj(fb, 0);
• mxsfb_enable_axi_clk(mxsfb);
• writel(gem->paddr, mxsfb->base + mxsfb->devdata->next_buf);

• mxsfb_update_hw_next_buf(mxsfb); mxsfb_disable_axi_clk(mxsfb);

} diff --git a/drivers/gpu/drm/mxsfb/mxsfb_drv.c b/drivers/gpu/drm/mxsfb/mxsfb_drv.c index 5cae8db9dcd4..c889cac2e275 100644 --- a/drivers/gpu/drm/mxsfb/mxsfb_drv.c +++ b/drivers/gpu/drm/mxsfb/mxsfb_drv.c @@ -100,23 +100,27 @@ static const struct drm_mode_config_funcs mxsfb_mode_config_funcs = {

static void mxsfb_pipe_enable(struct drm_simple_display_pipe *pipe, struct drm_crtc_state *crtc_state) { struct mxsfb_drm_private *mxsfb = drm_pipe_to_mxsfb_drm_private(pipe);

• struct drm_device *drm = pipe->plane.dev;

• pm_runtime_get_sync(drm->dev); drm_panel_prepare(mxsfb->panel); mxsfb_crtc_enable(mxsfb); drm_panel_enable(mxsfb->panel);

}

static void mxsfb_pipe_disable(struct drm_simple_display_pipe *pipe) { struct mxsfb_drm_private *mxsfb = drm_pipe_to_mxsfb_drm_private(pipe);

• struct drm_device *drm = pipe->plane.dev;

  drm_panel_disable(mxsfb->panel); mxsfb_crtc_disable(mxsfb); drm_panel_unprepare(mxsfb->panel);

• pm_runtime_put_sync(drm->dev);

}

static void mxsfb_pipe_update(struct drm_simple_display_pipe *pipe, struct drm_plane_state *plane_state) { @@ -175,10 +179,11 @@ static int mxsfb_load(struct drm_device *drm, unsigned long flags) if (!mxsfb) return -ENOMEM;

drm->dev_private = mxsfb; mxsfb->devdata = &mxsfb_devdata[pdev->id_entry->driver_data];

• platform_set_drvdata(pdev, drm);

  res = platform_get_resource(pdev, IORESOURCE_MEM, 0); mxsfb->base = devm_ioremap_resource(drm->dev, res); if (IS_ERR(mxsfb->base)) return PTR_ERR(mxsfb->base);

@@ -256,12 +261,10 @@ static int mxsfb_load(struct drm_device *drm, unsigned long flags) mxsfb->fbdev = NULL; dev_err(drm->dev, "Failed to init FB CMA area\n"); goto err_cma; }

• platform_set_drvdata(pdev, drm);

• drm_helper_hpd_irq_event(drm);

  return 0;

err_cma: @@ -417,17 +420,82 @@ static int mxsfb_remove(struct platform_device *pdev) drm_dev_unref(drm);

return 0; }

+#ifdef CONFIG_PM +static int mxsfb_runtime_suspend(struct device *dev) +{

• struct drm_device *drm = dev_get_drvdata(dev);
• struct mxsfb_drm_private *mxsfb = drm->dev_private;
• if (!drm->registered)

• return 0;
  

• if (mxsfb->enabled) {

• mxsfb_crtc_disable(mxsfb);
  

• mxsfb->suspended = true;
  

• }
• return 0;

+}

+static int mxsfb_runtime_resume(struct device *dev) +{

• struct drm_device *drm = dev_get_drvdata(dev);
• struct mxsfb_drm_private *mxsfb = drm->dev_private;
• if (!drm->registered || !mxsfb->suspended)

• return 0;
  

• mxsfb_crtc_enable(mxsfb);
• mxsfb->suspended = false;
• return 0;

+}

+static int mxsfb_suspend(struct device *dev) +{

• struct drm_device *drm = dev_get_drvdata(dev);
• struct mxsfb_drm_private *mxsfb = drm->dev_private;
• if (mxsfb->enabled) {

• mxsfb_crtc_disable(mxsfb);
  

• mxsfb->suspended = true;
  

• }
• return 0;

+}

+static int mxsfb_resume(struct device *dev) +{

• struct drm_device *drm = dev_get_drvdata(dev);
• struct mxsfb_drm_private *mxsfb = drm->dev_private;
• if (!mxsfb->suspended)

• return 0;
  

• mxsfb_crtc_enable(mxsfb);
• mxsfb->suspended = false;
• return 0;

+} +#endif

+static const struct dev_pm_ops mxsfb_pm_ops = {

• SET_RUNTIME_PM_OPS(mxsfb_runtime_suspend, mxsfb_runtime_resume, NULL)
• SET_SYSTEM_SLEEP_PM_OPS(mxsfb_suspend, mxsfb_resume)

+};

static struct platform_driver mxsfb_platform_driver = { .probe = mxsfb_probe, .remove = mxsfb_remove, .id_table = mxsfb_devtype, .driver = { .name = "mxsfb", .of_match_table = mxsfb_dt_ids,

• .pm = &mxsfb_pm_ops,
  

  },

};

module_platform_driver(mxsfb_platform_driver);

diff --git a/drivers/gpu/drm/mxsfb/mxsfb_drv.h b/drivers/gpu/drm/mxsfb/mxsfb_drv.h index 5d0883fc805b..d8ef4a053f0e 100644 --- a/drivers/gpu/drm/mxsfb/mxsfb_drv.h +++ b/drivers/gpu/drm/mxsfb/mxsfb_drv.h @@ -36,10 +36,13 @@ struct mxsfb_drm_private {

struct drm_simple_display_pipe pipe; struct drm_connector connector; struct drm_panel *panel; struct drm_fbdev_cma *fbdev;

• bool enabled;
• bool suspended;

};

int mxsfb_setup_crtc(struct drm_device *dev); int mxsfb_create_output(struct drm_device *dev);