linux-kernel - Re: [PATCH v5] fbtft: add tearing signal detect

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Message-ID: <20210127141927.00004472@gmail.com>
Date:   Wed, 27 Jan 2021 14:19:27 +0800
From:   carlis <zhangxuezhi3@...il.com>
To:     Dan Carpenter <dan.carpenter@...cle.com>
Cc:     gregkh@...uxfoundation.org, devel@...verdev.osuosl.org,
        linux-fbdev@...r.kernel.org, mh12gx2825@...il.com,
        oliver.graute@...oconnector.com, linux-kernel@...r.kernel.org,
        dri-devel@...ts.freedesktop.org, sbrivio@...hat.com,
        colin.king@...onical.com, zhangxuezhi1@...ong.com
Subject: Re: [PATCH v5] fbtft: add tearing signal detect

On Wed, 27 Jan 2021 08:45:23 +0300
Dan Carpenter <dan.carpenter@...cle.com> wrote:

> On Wed, Jan 27, 2021 at 09:32:20AM +0800, Carlis wrote:
> > @@ -82,6 +111,29 @@ 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 (par->gpio.te) {
> > +		init_completion(&spi_panel_te);
> > +		mutex_init(&te_mutex);
> > +		rc = devm_request_irq(dev,
> > +				      gpiod_to_irq(par->gpio.te),
> > +				     spi_panel_te_handler,
> > IRQF_TRIGGER_RISING,
> > +				     "TE_GPIO", par);
> > +		if (rc) {
> > +			pr_err("TE request_irq failed.\n");
> > +			devm_gpiod_put(dev, par->gpio.te);
> > +			par->gpio.te = NULL;
> > +		} else {
> > +
> > disable_irq_nosync(gpiod_to_irq(par->gpio.te));
> > +			pr_info("TE request_irq completion.\n");
> > +		}
> > +	} else {
> > +		pr_info("%s:%d, TE gpio not specified\n",
> > +			__func__, __LINE__);
> > +	}  
> 
> I'm sorry that I was not clear before.  This code will crash if
> devm_gpiod_get_index_optional() returns an error.  You *NEED* to check
> for error pointers and return the error code.  Write it exactly 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);
> 
> 	if (par->gpio.te) {
> 		init_completion(&spi_panel_te);
> 
> 
> regards,
> dan carpenter
> 

hi,i will 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);
		pr_err("Failed to request  te gpio: %d\n", rc);
		par->gpio.te = NULL;
	}
	if (par->gpio.te) {
		init_completion(&spi_panel_te);
		mutex_init(&te_mutex);
		rc = devm_request_irq(dev,
				      gpiod_to_irq(par->gpio.te),
				     spi_panel_te_handler,
IRQF_TRIGGER_RISING, "TE_GPIO", par);
		if (rc) {
			pr_err("TE request_irq failed.\n");
			devm_gpiod_put(dev, par->gpio.te);
			par->gpio.te = NULL;
		} else {
			disable_irq_nosync(gpiod_to_irq(par->gpio.te));
			pr_info("TE request_irq completion.\n");
		}
	} else {
		pr_info("%s:%d, TE gpio not specified\n",
			__func__, __LINE__);
	}

regards,
zhangxuezhi