[v4,1/5] drm/mxsfb: Move axi clk enable/disable to crtc enable/disable

Commit Message

Leonard Crestez Aug. 8, 2018, 4:08 p.m. UTC

The main axi clk is disabled at the end of mxsfb_crtc_mode_set_nofb and
immediately reenabled in mxsfb_enable_controller.

Avoid this by moving the handling of axi clk one level up to
mxsfb_crtc_enable. Do the same for mxsfb_crtc_disable for simmetry

This shouldn't have any functional effect.

Signed-off-by: Leonard Crestez <[e-mail]>
---
 drivers/gpu/drm/mxsfb/mxsfb_crtc.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

Comments

Leonard Crestez Aug. 13, 2018, 1:19 p.m. UTC | #1

On Wed, 2018-08-08 at 20:57 +0200, Stefan Agner wrote:
> On 08.08.2018 18:08, Leonard Crestez wrote:
> > The main axi clk is disabled at the end of mxsfb_crtc_mode_set_nofb and
> > immediately reenabled in mxsfb_enable_controller.
> > 
> > Avoid this by moving the handling of axi clk one level up to
> > mxsfb_crtc_enable. Do the same for mxsfb_crtc_disable for simmetry
> > 
> > This shouldn't have any functional effect.
> > 
> > Signed-off-by: Leonard Crestez <[e-mail]>
> 
> Thanks, looks good!
> 
> Reviewed-by: Stefan Agner <[e-mail]>

So what is next now that this entire series was reviewed? My guess is
that somebody needs to push it to drm-misc-next.

However 4.18 was just released and I'm not sure how this interacts with
drm. As far as I can tell drm-misc-next is always open and a patch
accepted now will make it into 4.20, based on this graph:

https://01.org/linuxgraphics/gfx-docs/maintainer-tools/drm-misc.html#merge-timeline

--
Regards,
Leonard

Patch

diff --git a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
index 0abe77675b76..e4fcbb65b969 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
+++ b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
@@ -127,11 +127,10 @@  static void mxsfb_enable_controller(struct mxsfb_drm_private *mxsfb)
 	u32 reg;
 
 	if (mxsfb->clk_disp_axi)
 		clk_prepare_enable(mxsfb->clk_disp_axi);
 	clk_prepare_enable(mxsfb->clk);
-	mxsfb_enable_axi_clk(mxsfb);
 
 	/* If it was disabled, re-enable the mode again */
 	writel(CTRL_DOTCLK_MODE, mxsfb->base + LCDC_CTRL + REG_SET);
 
 	/* Enable the SYNC signals first, then the DMA engine */
@@ -157,12 +156,10 @@  static void mxsfb_disable_controller(struct mxsfb_drm_private *mxsfb)
 
 	reg = readl(mxsfb->base + LCDC_VDCTRL4);
 	reg &= ~VDCTRL4_SYNC_SIGNALS_ON;
 	writel(reg, mxsfb->base + LCDC_VDCTRL4);
 
-	mxsfb_disable_axi_clk(mxsfb);
-
 	clk_disable_unprepare(mxsfb->clk);
 	if (mxsfb->clk_disp_axi)
 		clk_disable_unprepare(mxsfb->clk_disp_axi);
 }
 
@@ -206,11 +203,10 @@  static void mxsfb_crtc_mode_set_nofb(struct mxsfb_drm_private *mxsfb)
 	/*
 	 * It seems, you can't re-program the controller if it is still
 	 * running. This may lead to shifted pictures (FIFO issue?), so
 	 * first stop the controller and drain its FIFOs.
 	 */
-	mxsfb_enable_axi_clk(mxsfb);
 
 	/* Mandatory eLCDIF reset as per the Reference Manual */
 	err = mxsfb_reset_block(mxsfb->base);
 	if (err)
 		return;
@@ -267,23 +263,23 @@  static void mxsfb_crtc_mode_set_nofb(struct mxsfb_drm_private *mxsfb)
 	       SET_VERT_WAIT_CNT(m->crtc_vtotal - m->crtc_vsync_start),
 	       mxsfb->base + LCDC_VDCTRL3);
 
 	writel(SET_DOTCLK_H_VALID_DATA_CNT(m->hdisplay),
 	       mxsfb->base + LCDC_VDCTRL4);
-
-	mxsfb_disable_axi_clk(mxsfb);
 }
 
 void mxsfb_crtc_enable(struct mxsfb_drm_private *mxsfb)
 {
+	mxsfb_enable_axi_clk(mxsfb);
 	mxsfb_crtc_mode_set_nofb(mxsfb);
 	mxsfb_enable_controller(mxsfb);
 }
 
 void mxsfb_crtc_disable(struct mxsfb_drm_private *mxsfb)
 {
 	mxsfb_disable_controller(mxsfb);
+	mxsfb_disable_axi_clk(mxsfb);
 }
 
 void mxsfb_plane_atomic_update(struct mxsfb_drm_private *mxsfb,
 			       struct drm_plane_state *state)
 {