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SubjectRe: [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);
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