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

From: Geert Uytterhoeven
Date: Thu Jan 28 2021 - 06:16:29 EST


Hi Carlis,

On Thu, Jan 28, 2021 at 12:03 PM carlis <zhangxuezhi3@xxxxxxxxx> wrote:
> On Thu, 28 Jan 2021 10:42:54 +0100
> Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
> > On Thu, Jan 28, 2021 at 7:53 AM Kari Argillander
> > <kari.argillander@xxxxxxxxx> 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@xxxxxxxxx> 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.
> >
> > devm_gpiod_get_index_optional() returns NULL, not an error, if the
> > GPIO is not found. So if IS_ERR() is the right check.
> >
> > And checks for -EPROBE_DEFER can be handled automatically
> > by using dev_err_probe() instead of dev_err().
> >
> hi, i fix it like below!?
> 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_probe(par->info->device, rc, "Failed to request
> te gpio\n"); return rc;
> }
> if (par->gpio.te) {
> init_completion(&spi_panel_te);
> rc = devm_request_irq(dev,
> gpiod_to_irq(par->gpio.te),
> spi_panel_te_handler,
> IRQF_TRIGGER_RISING, "TE_GPIO", par);
> if (rc) {
> dev_err(par->info->device, "TE request_irq
> failed.\n"); return rc;

dev_err_probe()

> }
>
> disable_irq_nosync(gpiod_to_irq(par->gpio.te));
> } else {
> dev_info(par->info->device, "%s:%d, TE gpio not
> specified\n", __func__, __LINE__);
> }

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds