S430 4.3" TFT not working as expected

[avafinger]

Hi @rafaello7 ,

I received a couple of S430 LCD recently and gave it try with your kernel 4.14.7+ but seems not working properly.
The S430 is detected and started displaying the kernel loading for a few seconds ( ~2 s ) and a blank screen suddenly follows.

The same kernel works fine with X710.

Kernel 4.14 finds the correct LCD:

	},{
		.name = "s430",
		.onewireType = 31,
		.i2c_touch_drv = "hx8528-a",
		.i2c_touch_reg = 0x48,
		.bpc  = 8,
		.p_width = 108,
		.p_height = 64,
		.mode = &mode_s430,
	},{

static const struct drm_display_mode mode_s430 = {
	.clock = 28492,
	.hdisplay = 480,
	.hsync_start = 480 + 64,
	.hsync_end = 480 + 64 + 16,
	.htotal = 480 + 64 + 16 + 0,
	.vdisplay = 800,
	.vsync_start = 800 + 32,
	.vsync_end = 800 + 32 + 16,
	.vtotal = 800 + 32 + 16 + 0,
	.vrefresh = 60,
	.flags = DRM_MODE_FLAG_NCSYNC
};

These are the timings for the kernel 4.4:

static struct lcd_desc s430 = {
	.width= 480,
	.height = 800,
	.p_width = 108,
	.p_height = 64,
	.bpp = 24,
	.freq = 60,

	.timing = {
		.h_fp = 64,
		.h_bp = 0,
		.h_sw = 16,
		.v_fp = 32,
		.v_fpe = 1,
		.v_bp = 0,
		.v_bpe = 1,
		.v_sw = 16,
	},
	.polarity = {
		.rise_vclk = 1,
		.inv_hsync = 1,
		.inv_vsync = 1,
		.inv_vden = 0,
	},
};

Do you have any idea what could cause this issue?

Appreciate if you can help.
Cheers

[avafinger]

@rafaello7 ,
I will stick with 4.4 for a while until you decide or get motivated to work with 4.14.y. I wished to work with your kernel that i feel is a better work than 4.4, btw kernel 4.14.y has DVFS broken, idle mode i get 700 Mhz ~ 1100 Mhz while 400 Mhz in 4.4. Maybe you move your stuff to 4.4. Thanks for your work anyways.
BR
@avafinger

[avafinger]

Reopen if you decide so.

[rafaello7]

in lcd_desc for kernel 4.4:
h_fp - horizontal front porch
h_sw - horizontal sync width
h_bp - horizontal back porch
v_fp - vertical front porch
v_sw - vertical sync width
v_bp - vertical back porch
Timings for kernel 4.14 may be calculated using formulas:
hsync_start = width + h_fp
hsync_end = width + h_fp + h_sw
htotal = width + h_fp + h_sw + h_bp
Vertical timings analogously.
The clock value is calculated as is htotal * vtotal * vrefresh / 1000 (it is in kHz).
Maybe the flags are bad, try to add DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC.