Re: [PATCH 07/13] video: Add Sitronix st7789v panel driver

[Sascha Hauer <s.hauer@pengutronix.de>]

On Thu, Sep 26, 2024 at 04:16:13PM +0200, Ahmad Fatoum wrote:
> Hello Sascha,
> 
> On 26.09.24 15:15, Sascha Hauer wrote:
> > +	ret = st7789v_read_data(ctx, MIPI_DCS_GET_DISPLAY_ID, ids, ST7789V_IDS_SIZE);
> > +	if (ret)
> > +		return ret;
> > +printf("%s: %02x %02x %02x\n", __func__, ids[0], ids[1], ids[2]);
> 
> Debugging left-over.
> 
> > +static int st7789v_prepare(struct st7789v *ctx)
> > +{
> 
> 
> > +	ret = regulator_enable(ctx->power);
> > +	if (ret)
> > +		return ret;
> > +
> > +	gpiod_set_value(ctx->reset, 1);
> > +	mdelay(30);
> > +	gpiod_set_value(ctx->reset, 0);
> > +	mdelay(120);
> 
> Ouch. That's quite a bit of wasted time. Could it make sense to move device
> out of reset in probe function instead?

We could play tricks like store the time we released the reset in the
driver struct and only wait the remaining time here, but I think that's
not really worth it.

Sascha

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