i.MX Processors中的主题 Re: Why IMX8QXP spend too much time to Initialization ldb

Why IMX8QXP spend too much time to Initialization ldb

shalanyang — Wed, 02 Jan 2019 09:44:30 GMT

Why IMX8QXP spend too much time to Initialization ldb ?

should can we delete the delay time ?or decrease the time ? the code is follow：

static const struct panel_desc jdi_tx26d202vm0bwa = {
.timings = &jdi_tx26d202vm0bwa_timing,
.num_timings = 1,
.bpc = 8,
.size = {
.width = 300,
.height = 150,
},
.delay = {
/*
* The panel spec recommends one second delay
* to the below items. However, it's a bit too
* long in pratical. Based on tests, it turns
* out 100 milliseconds is fine.
*/
.prepare = 100,
.enable = 100,
.unprepare = 100,
.disable = 100,
},
.bus_format = MEDIA_BUS_FMT_ARGB8888_1X32,//MEDIA_BUS_FMT_RGB888_1X7X4_SPWG,
};

static int panel_simple_prepare(struct drm_panel *panel)
{
struct panel_simple *p = to_panel_simple(panel);
int err;
if (p->prepared)
return 0;

err = regulator_enable(p->supply);
if (err < 0) {
dev_err(panel->dev, "failed to enable supply: %d\n", err);
return err;
}
if (p->enable_gpio)
gpiod_set_value_cansleep(p->enable_gpio, 1);

printk("%s===========\n",__FUNCTION__);
if (p->desc->delay.prepare)
msleep(p->desc->delay.prepare);
printk("%s============p->desc->delay.prepare=%u\n",__FUNCTION__,p->desc->delay.prepare);
p->prepared = true;

return 0;
}

console log:

.....

[ 0.404633] panel_simple_prepare===========
[ 0.511409] panel_simple_prepare============p->desc->delay.prepare=100

.....

why delay 100ms ? can we decrease it to 10ms or less?

I replace msleep(p->desc->delay.prepare) with msleep(10) ，the OS could startup normally and the

lvds can show normal, Is there any problem ?Anyone could help me ?

Re: Why IMX8QXP spend too much time to Initialization ldb

igorpadykov — Thu, 03 Jan 2019 08:06:35 GMT

Hi shalan

as you noted: "The panel spec recommends one second delay.."

so seems this is panel issue, not i.MX8QXP and may be posted on

tech support jdi lcd vendor

Best regards
igor
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Re: Why IMX8QXP spend too much time to Initialization ldb

shalanyang — Fri, 04 Jan 2019 08:06:44 GMT

thanks for you answer.

you means the problem is in the lcd? different lcd may be have different spec ?so we need lcd verdor support ?