Hello Andy Shevchenko,
The patch 7d84a63a39b7: "backlight: hx8357: Convert to agnostic GPIO
API" from Dec 7, 2023 (linux-next), leads to the following Smatch
static checker warning:
drivers/video/backlight/hx8357.c:612 hx8357_probe()
error: potential NULL/IS_ERR bug 'lcd->im_pins'
drivers/video/backlight/hx8357.c
580 static int hx8357_probe(struct spi_device *spi)
581 {
582 struct device *dev = &spi->dev;
583 struct lcd_device *lcdev;
584 struct hx8357_data *lcd;
585 const struct of_device_id *match;
586 int i, ret;
587
588 lcd = devm_kzalloc(&spi->dev, sizeof(*lcd), GFP_KERNEL);
589 if (!lcd)
590 return -ENOMEM;
591
592 ret = spi_setup(spi);
593 if (ret < 0) {
594 dev_err(&spi->dev, "SPI setup failed.\n");
595 return ret;
596 }
597
598 lcd->spi = spi;
599
600 match = of_match_device(hx8357_dt_ids, &spi->dev);
601 if (!match || !match->data)
602 return -EINVAL;
603
604 lcd->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
605 if (IS_ERR(lcd->reset))
606 return dev_err_probe(dev, PTR_ERR(lcd->reset), "failed to request reset GPIO\n");
607 gpiod_set_consumer_name(lcd->reset, "hx8357-reset");
608
609 lcd->im_pins = devm_gpiod_get_array_optional(dev, "im", GPIOD_OUT_LOW);
610 if (IS_ERR(lcd->im_pins))
611 return dev_err_probe(dev, PTR_ERR(lcd->im_pins), "failed to request im GPIOs\n");
--> 612 if (lcd->im_pins->ndescs < HX8357_NUM_IM_PINS)
^^^^^^^^^^^^
I think _optional() functions can return NULL.
613 return dev_err_probe(dev, -EINVAL, "not enough im GPIOs\n");
614
615 for (i = 0; i < HX8357_NUM_IM_PINS; i++)
616 gpiod_set_consumer_name(lcd->im_pins->desc[i], "im_pins");
617
618 lcdev = devm_lcd_device_register(&spi->dev, "mxsfb", &spi->dev, lcd,
619 &hx8357_ops);
620 if (IS_ERR(lcdev)) {
621 ret = PTR_ERR(lcdev);
622 return ret;
623 }
624 spi_set_drvdata(spi, lcdev);
625
626 hx8357_lcd_reset(lcdev);
627
628 ret = ((int (*)(struct lcd_device *))match->data)(lcdev);
629 if (ret) {
630 dev_err(&spi->dev, "Couldn't initialize panel\n");
631 return ret;
632 }
633
634 dev_info(&spi->dev, "Panel probed\n");
635
636 return 0;
637 }
regards,
dan carpenter
