From 8d6b6c05b8e33d11e3fb3203309385e1a9cceecd Mon Sep 17 00:00:00 2001 From: Cosmo Chou Date: Wed, 15 Jul 2026 16:07:47 +0800 Subject: [PATCH] leds: pca9532: Fix phantom device registration on missing hardware The initial PWM and PSC register writes in pca9532_configure() do not check the return values of i2c_smbus_write_byte_data(). If the I2C device is physically absent from the bus, the write fails with -ENXIO. However, the driver ignores this error and allows probe() to complete successfully. This results in the registration of phantom LED class devices and gpiochips backed by non-existent hardware. Subsequent GPIO reads from these phantom chips return bogus values (due to -ENXIO being truncated to an unsigned char in pca9532_gpio_get_value()), silently corrupting hardware state tracking in userspace. Propagate the I2C write failures back to probe() so the driver core can gracefully abort binding and release devres-managed resources. Fixes: e14fa82439d3 ("leds: Add pca9532 led driver") Signed-off-by: Cosmo Chou Reviewed-by: Bartosz Golaszewski Link: https://patch.msgid.link/20260715080747.1638097-1-chou.cosmo@gmail.com Signed-off-by: Lee Jones --- drivers/leds/leds-pca9532.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/leds/leds-pca9532.c b/drivers/leds/leds-pca9532.c index 2d37e00e459d..b2e081c8f139 100644 --- a/drivers/leds/leds-pca9532.c +++ b/drivers/leds/leds-pca9532.c @@ -397,10 +397,14 @@ static int pca9532_configure(struct i2c_client *client, for (i = 0; i < 2; i++) { data->pwm[i] = pdata->pwm[i]; data->psc[i] = pdata->psc[i]; - i2c_smbus_write_byte_data(client, PCA9532_REG_PWM(maxleds, i), - data->pwm[i]); - i2c_smbus_write_byte_data(client, PCA9532_REG_PSC(maxleds, i), - data->psc[i]); + err = i2c_smbus_write_byte_data(client, PCA9532_REG_PWM(maxleds, i), + data->pwm[i]); + if (err < 0) + return err; + err = i2c_smbus_write_byte_data(client, PCA9532_REG_PSC(maxleds, i), + data->psc[i]); + if (err < 0) + return err; } data->hw_blink = true;