The patch titled gpio: fix probe() error return in gpio driver probes has been added to the -mm tree. Its filename is gpio-fix-probe-error-return-in-gpio-driver-probes.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: gpio: fix probe() error return in gpio driver probes From: Ben Dooks <ben-linux@xxxxxxxxx> A number of drivers in drivers/gpio return -ENODEV when confronted with missing setup parameters such as the platform data. However, returning -ENODEV causes the driver layer to silently ignore the driver as it assumes the probe did not find anything and was only speculative. To make life easier to discern why a driver is not being attached, change to returning -EINVAL, which is a better description of the fact that the driver data was not valid. Also add a set of dev_dbg() statements to the error paths to provide an better explanation of the error as there may be more that one point in the driver. Signed-off-by: Ben Dooks <ben-linux@xxxxxxxxx> Cc: David Brownell <david-b@xxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/gpio/max7301.c | 6 ++++-- drivers/gpio/max732x.c | 6 ++++-- drivers/gpio/mcp23s08.c | 6 ++++-- drivers/gpio/pca953x.c | 6 ++++-- drivers/gpio/pcf857x.c | 12 ++++++++---- 5 files changed, 24 insertions(+), 12 deletions(-) diff -puN drivers/gpio/max7301.c~gpio-fix-probe-error-return-in-gpio-driver-probes drivers/gpio/max7301.c --- a/drivers/gpio/max7301.c~gpio-fix-probe-error-return-in-gpio-driver-probes +++ a/drivers/gpio/max7301.c @@ -217,8 +217,10 @@ static int __devinit max7301_probe(struc int i, ret; pdata = spi->dev.platform_data; - if (!pdata || !pdata->base) - return -ENODEV; + if (!pdata || !pdata->base) { + dev_dbg(&spi->dev, "incorrect or missing platform data\n"); + return -EINVAL; + } /* * bits_per_word cannot be configured in platform data diff -puN drivers/gpio/max732x.c~gpio-fix-probe-error-return-in-gpio-driver-probes drivers/gpio/max732x.c --- a/drivers/gpio/max732x.c~gpio-fix-probe-error-return-in-gpio-driver-probes +++ a/drivers/gpio/max732x.c @@ -267,8 +267,10 @@ static int __devinit max732x_probe(struc int ret, nr_port; pdata = client->dev.platform_data; - if (pdata == NULL) - return -ENODEV; + if (pdata == NULL) { + dev_dbg(&client->dev, "no platform data\n"); + return -EINVAL; + } chip = kzalloc(sizeof(struct max732x_chip), GFP_KERNEL); if (chip == NULL) diff -puN drivers/gpio/mcp23s08.c~gpio-fix-probe-error-return-in-gpio-driver-probes drivers/gpio/mcp23s08.c --- a/drivers/gpio/mcp23s08.c~gpio-fix-probe-error-return-in-gpio-driver-probes +++ a/drivers/gpio/mcp23s08.c @@ -310,8 +310,10 @@ static int mcp23s08_probe(struct spi_dev unsigned base; pdata = spi->dev.platform_data; - if (!pdata || !gpio_is_valid(pdata->base)) - return -ENODEV; + if (!pdata || !gpio_is_valid(pdata->base)) { + dev_dbg(&spi->dev, "invalid or missing platform data\n"); + return -EINVAL; + } for (addr = 0; addr < 4; addr++) { if (!pdata->chip[addr].is_present) diff -puN drivers/gpio/pca953x.c~gpio-fix-probe-error-return-in-gpio-driver-probes drivers/gpio/pca953x.c --- a/drivers/gpio/pca953x.c~gpio-fix-probe-error-return-in-gpio-driver-probes +++ a/drivers/gpio/pca953x.c @@ -202,8 +202,10 @@ static int __devinit pca953x_probe(struc int ret; pdata = client->dev.platform_data; - if (pdata == NULL) - return -ENODEV; + if (pdata == NULL) { + dev_dbg(&client->dev, "no platform data\n"); + return -EINVAL; + } chip = kzalloc(sizeof(struct pca953x_chip), GFP_KERNEL); if (chip == NULL) diff -puN drivers/gpio/pcf857x.c~gpio-fix-probe-error-return-in-gpio-driver-probes drivers/gpio/pcf857x.c --- a/drivers/gpio/pcf857x.c~gpio-fix-probe-error-return-in-gpio-driver-probes +++ a/drivers/gpio/pcf857x.c @@ -188,8 +188,10 @@ static int pcf857x_probe(struct i2c_clie int status; pdata = client->dev.platform_data; - if (!pdata) - return -ENODEV; + if (!pdata) { + dev_dbg(&client->dev, "no platform data\n"); + return -EINVAL; + } /* Allocate, initialize, and register this gpio_chip. */ gpio = kzalloc(sizeof *gpio, GFP_KERNEL); @@ -248,8 +250,10 @@ static int pcf857x_probe(struct i2c_clie else status = i2c_read_le16(client); - } else - status = -ENODEV; + } else { + dev_dbg(&client->dev, "unsupported number of gpios\n"); + status = -EINVAL; + } if (status < 0) goto fail; _ Patches currently in -mm which might be from ben-linux@xxxxxxxxx are i2c-incremental-i2c-mpc-driver-fix-for-multi-master-i2c-busses.patch sm501-fix-section-mismatches.patch mmc-s3cmci-fix-hangup-in-do_pio_write.patch gpio-fix-probe-error-return-in-gpio-driver-probes.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html