video: mxsfb: Configure the clock after eLCDIF reset

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>

diff --git a/drivers/video/mxsfb.c b/drivers/video/mxsfb.c
index c52981053e99ac31476a48f3d0e3d45dc3030295..d73a8bac9918cf8f46126573d4bb72190a00ab5a 100644 (file)
--- 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);
 }