[U-Boot] [PATCH] video: mxsfb: Configure the clock after eLCDIF reset

[U-Boot] [PATCH] video: mxsfb: Configure the clock after eLCDIF reset

[Fabio Estevam]

Running stress reboot test on a i.MX6ULL evk board with a
custom LCD can lead to splash screen failure (black screen).

After comparing the eLCDIF initialization with the Linux kernel
driver, it was noticed that the eLCDIF reset is the first operation
that needs to be done.

So do like the eLCDIF Linux driver and move the eLCDIF clock
frequency configuration after the eLCDIF reset and just prior to
setting the RUN bit.

With this change applied, no more black screen issues has been
found during overnight reboot stress tests.

Signed-off-by: Fabio Estevam <festevam@gmail.com>
---
 drivers/video/mxsfb.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/video/mxsfb.c b/drivers/video/mxsfb.c
index 6922a130c6..fcdf29be5e 100644
--- a/drivers/video/mxsfb.c
+++ b/drivers/video/mxsfb.c
@@ -57,9 +57,6 @@ static void mxs_lcd_init(u32 fb_addr, struct ctfb_res_modes *mode, int bpp)
 	uint32_t word_len = 0, bus_width = 0;
 	uint8_t valid_data = 0;
 
-	/* Kick in the LCDIF clock */
-	mxs_set_lcdclk(MXS_LCDIF_BASE, PS2KHZ(mode->pixclock));
-
 	/* Restart the LCDIF block */
 	mxs_reset_block(&regs->hw_lcdif_ctrl_reg);
 
@@ -130,6 +127,9 @@ static void mxs_lcd_init(u32 fb_addr, struct ctfb_res_modes *mode, int bpp)
 	/* FIFO cleared */
 	writel(LCDIF_CTRL1_FIFO_CLEAR, &regs->hw_lcdif_ctrl1_clr);
 
+	/* Kick in the LCDIF clock */
+	mxs_set_lcdclk(MXS_LCDIF_BASE, PS2KHZ(mode->pixclock));
+
 	/* RUN! */
 	writel(LCDIF_CTRL_RUN, &regs->hw_lcdif_ctrl_set);
 }
-- 
2.17.1

[U-Boot] [PATCH] video: mxsfb: Configure the clock after eLCDIF reset

[Anatolij Gustschin]

On Fri,  1 Nov 2019 09:25:21 -0300
Fabio Estevam festevam at gmail.com wrote:
...
>  drivers/video/mxsfb.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)

Applied to u-boot-video, thanks!

--
Anatolij