Re: [PATCH v10] staging: fbtft: add tearing signal detect

[carlis <zhangxuezhi3@gmail.com>]

On Thu, 28 Jan 2021 08:52:33 +0200
Kari Argillander <kari.argillander@gmail.com> wrote:

> On Thu, Jan 28, 2021 at 09:42:58AM +0800, carlis wrote:
> > On Thu, 28 Jan 2021 00:32:22 +0200
> > Kari Argillander <kari.argillander@gmail.com> wrote:  
> > > >  #include "fbtft.h"
> > > >  
> > > >  #define DRVNAME "fb_st7789v"
> > > > @@ -66,6 +69,32 @@ enum st7789v_command {
> > > >  #define MADCTL_MX BIT(6) /* bitmask for column address order */
> > > >  #define MADCTL_MY BIT(7) /* bitmask for page address order */
> > > >  
> > > > +#define SPI_PANEL_TE_TIMEOUT	400 /* msecs */
> > > > +static struct mutex te_mutex;/* mutex for set te gpio irq
> > > > status */    
> > > 
> > > Space after ;  
> > hi, i have fix it in the patch v11  
> > >   
> 
> Yeah sorry. I accidentally review wrong patch. But mostly stuff are
> still relevant.
> 
> > > > @@ -82,6 +111,33 @@ enum st7789v_command {
> > > >   */
> > > >  static int init_display(struct fbtft_par *par)
> > > >  {
> > > > +	int rc;
> > > > +	struct device *dev = par->info->device;
> > > > +
> > > > +	par->gpio.te = devm_gpiod_get_index_optional(dev,
> > > > "te", 0, GPIOD_IN);
> > > > +	if (IS_ERR(par->gpio.te)) {
> > > > +		rc = PTR_ERR(par->gpio.te);
> > > > +		dev_err(par->info->device, "Failed to request
> > > > te gpio: %d\n", rc);
> > > > +		return rc;
> > > > +	}    
> > > 
> > > You request with optinal and you still want to error out? We could
> > > just continue and not care about that error. User will be happier
> > > if device still works somehow.  
> > You mean i just delete this dev_err print ?!
> > like this:
> > 	par->gpio.te = devm_gpiod_get_index_optional(dev, "te",
> > 0,GPIOD_IN); 
> >         if (IS_ERR(par->gpio.te))
> > 		return PTR_ERR(par->gpio.te);  
> 
> Not exactly. I'm suggesting something like this.
> 
> if (IS_ERR(par->gpio.te) == -EPROBE_DEFER) {
> 	return -EPROBE_DEFER;
> 
> if (IS_ERR(par->gpio.te))
> 	par-gpio.te = NULL;
> 
> This like beginning of your patch series but the difference is that if
> EPROBE_DEFER then we will try again later. Any other error and we will
> just ignore TE gpio. But this is up to you what you want to do. To me
> this just seems place where this kind of logic can work.
> 
> > > > +		if (par->gpio.te) {
> > > > +			set_spi_panel_te_irq_status(par, true);
> > > > +			reinit_completion(&spi_panel_te);
> > > > +			ret =
> > > > wait_for_completion_timeout(&spi_panel_te,
> > > > +
> > > > msecs_to_jiffies(SPI_PANEL_TE_TIMEOUT));
> > > > +			if (ret == 0)    
> > > 
> > > !ret
> > >   
> > > > +				dev_err(par->info->device,
> > > > "wait panel TE time out\n");
> > > > +		}
> > > > +		ret = par->fbtftops.write(par, par->txbuf.buf,
> > > > +					 startbyte_size +
> > > > to_copy
> > > > * 2);
> > > > +		if (par->gpio.te)
> > > > +			set_spi_panel_te_irq_status(par,
> > > > false);
> > > > +		if (ret < 0)
> > > > +			return ret;
> > > > +		remain -= to_copy;
> > > > +	}
> > > > +
> > > > +	return ret;    
> > > 
> > > Do we want to return something over 0? If not then this can be
> > > return 0. And then you do not need to even init ret value at the
> > > beginning.
> > > 
> > > Also wait little bit like Greg sayd before sending new version.
> > > Someone might nack about what I say or say something more.
> > >   
> > hi, i copy fbtft_write_vmem16_bus8 from file fbtft_bus.c and modify
> > it ,just add te wait logic, i will take more time to check this
> > original function.  
> 
> It might be ok or not. You should still check.

hi, i will check more carefully, now i have a new problem, Is there a
way to clear the interrupt pending state before opening it again?