Commit a342d215c206d955fea55d778e3803b29ee41b60

Authored by Ben Dooks
Committed by Linus Torvalds
1 parent 5b96f17290

gpio: fix probe() error return in gpio driver probes

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@fluff.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Showing 5 changed files with 24 additions and 12 deletions Side-by-side Diff

drivers/gpio/max7301.c
... ... @@ -217,8 +217,10 @@
217 217 int i, ret;
218 218  
219 219 pdata = spi->dev.platform_data;
220   - if (!pdata || !pdata->base)
221   - return -ENODEV;
  220 + if (!pdata || !pdata->base) {
  221 + dev_dbg(&spi->dev, "incorrect or missing platform data\n");
  222 + return -EINVAL;
  223 + }
222 224  
223 225 /*
224 226 * bits_per_word cannot be configured in platform data
drivers/gpio/max732x.c
... ... @@ -267,8 +267,10 @@
267 267 int ret, nr_port;
268 268  
269 269 pdata = client->dev.platform_data;
270   - if (pdata == NULL)
271   - return -ENODEV;
  270 + if (pdata == NULL) {
  271 + dev_dbg(&client->dev, "no platform data\n");
  272 + return -EINVAL;
  273 + }
272 274  
273 275 chip = kzalloc(sizeof(struct max732x_chip), GFP_KERNEL);
274 276 if (chip == NULL)
drivers/gpio/mcp23s08.c
... ... @@ -310,8 +310,10 @@
310 310 unsigned base;
311 311  
312 312 pdata = spi->dev.platform_data;
313   - if (!pdata || !gpio_is_valid(pdata->base))
314   - return -ENODEV;
  313 + if (!pdata || !gpio_is_valid(pdata->base)) {
  314 + dev_dbg(&spi->dev, "invalid or missing platform data\n");
  315 + return -EINVAL;
  316 + }
315 317  
316 318 for (addr = 0; addr < 4; addr++) {
317 319 if (!pdata->chip[addr].is_present)
drivers/gpio/pca953x.c
... ... @@ -202,8 +202,10 @@
202 202 int ret;
203 203  
204 204 pdata = client->dev.platform_data;
205   - if (pdata == NULL)
206   - return -ENODEV;
  205 + if (pdata == NULL) {
  206 + dev_dbg(&client->dev, "no platform data\n");
  207 + return -EINVAL;
  208 + }
207 209  
208 210 chip = kzalloc(sizeof(struct pca953x_chip), GFP_KERNEL);
209 211 if (chip == NULL)
drivers/gpio/pcf857x.c
... ... @@ -188,8 +188,10 @@
188 188 int status;
189 189  
190 190 pdata = client->dev.platform_data;
191   - if (!pdata)
192   - return -ENODEV;
  191 + if (!pdata) {
  192 + dev_dbg(&client->dev, "no platform data\n");
  193 + return -EINVAL;
  194 + }
193 195  
194 196 /* Allocate, initialize, and register this gpio_chip. */
195 197 gpio = kzalloc(sizeof *gpio, GFP_KERNEL);
... ... @@ -248,8 +250,10 @@
248 250 else
249 251 status = i2c_read_le16(client);
250 252  
251   - } else
252   - status = -ENODEV;
  253 + } else {
  254 + dev_dbg(&client->dev, "unsupported number of gpios\n");
  255 + status = -EINVAL;
  256 + }
253 257  
254 258 if (status < 0)
255 259 goto fail;