Re: [PATCH v4 2/5] drm/mxsfb: Fix initial corrupt frame when activating display

On 08.08.2018 18:08, Leonard Crestez wrote:

LCDIF will repeatedly display data from CUR_BUF and set CUR_BUF to NEXT_BUF when done. Since we are only ever writing to NEXT_BUF the display will show an initial corrupt frame.

Fix by writing the FB paddr to both CUR_BUF and NEXT_BUF when activating the CRTC.

Signed-off-by: Leonard Crestez leonard.crestez@nxp.com Tested-by: Philipp Zabel p.zabel@pengutronix.de

Reviewed-by: Stefan Agner stefan@agner.ch

---

drivers/gpu/drm/mxsfb/mxsfb_crtc.c | 45 +++++++++++++++++++++--------- 1 file changed, 32 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c index e4fcbb65b969..24b1f0c1432e 100644 --- a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c +++ b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c @@ -191,10 +191,25 @@ static int mxsfb_reset_block(void __iomem *reset_addr) return ret;

return clear_poll_bit(reset_addr, MODULE_CLKGATE); }

+static dma_addr_t mxsfb_get_fb_paddr(struct mxsfb_drm_private *mxsfb) +{

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

• return 0;
  

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

• return 0;
  

• return gem->paddr;

+}

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; @@ -267,12 +282,22 @@ static void mxsfb_crtc_mode_set_nofb(struct mxsfb_drm_private *mxsfb) mxsfb->base + LCDC_VDCTRL4); }

void mxsfb_crtc_enable(struct mxsfb_drm_private *mxsfb) {

• dma_addr_t paddr;
• mxsfb_enable_axi_clk(mxsfb); mxsfb_crtc_mode_set_nofb(mxsfb);
• /* Write cur_buf as well to avoid an initial corrupt frame */
• paddr = mxsfb_get_fb_paddr(mxsfb);
• if (paddr) {

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

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

• }
• mxsfb_enable_controller(mxsfb);

}

void mxsfb_crtc_disable(struct mxsfb_drm_private *mxsfb) { @@ -283,16 +308,12 @@ void mxsfb_crtc_disable(struct mxsfb_drm_private *mxsfb) 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;
  

• dma_addr_t paddr;

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

@@ -303,14 +324,12 @@ 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_disable_axi_clk(mxsfb);

• paddr = mxsfb_get_fb_paddr(mxsfb);
• if (paddr) {

• mxsfb_enable_axi_clk(mxsfb);
  

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

• mxsfb_disable_axi_clk(mxsfb);
  

• }

}