"of_get_named_gpio()" returns a negative error value if it fails
and drivers should check for this. This missing check was now
added to the matrix_keypad driver.
In my case "of_get_named_gpio()" returned -EPROBE_DEFER because
the referenced GPIOs belong to an I/O expander, which was not yet
probed at the point in time when the matrix_keypad driver was
loading. Because the driver did not check for errors from the
"of_get_named_gpio()" routine, it was assuming that "-EPROBE_DEFER"
is actually a GPIO number and continued as usual, which led to further
errors like this later on:
WARNING: CPU: 3 PID: 167 at drivers/gpio/gpiolib.c:114
gpio_to_desc+0xc8/0xd0
invalid GPIO -517
Note that the "GPIO number" -517 in the error message above is
actually "-EPROBE_DEFER".
As part of the patch a misleading error message "no platform data defined"
was also removed.
Thanks a lot to Sebastian Reichl for his analysis of the problem
and for pointing me into the right direction on how to fix this issue!
Signed-off-by: Christian Hoff <christian_hoff@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
drivers/input/keyboard/matrix_keypad.c | 22 ++++++++++++++--------
1 file changed, 14 insertions(+), 8 deletions(-)
diff --git a/drivers/input/keyboard/matrix_keypad.c b/drivers/input/keyboard/matrix_keypad.c
index f51ae09596ef..8a6be94b7838 100644
--- a/drivers/input/keyboard/matrix_keypad.c
+++ b/drivers/input/keyboard/matrix_keypad.c
@@ -407,7 +407,7 @@ matrix_keypad_parse_dt(struct device *dev)
struct matrix_keypad_platform_data *pdata;
struct device_node *np = dev->of_node;
unsigned int *gpios;
- int i, nrow, ncol;
+ int ret, i, nrow, ncol;
if (!np) {
dev_err(dev, "device lacks DT data\n");
@@ -444,7 +444,7 @@ matrix_keypad_parse_dt(struct device *dev)
&pdata->col_scan_delay_us);
gpios = devm_kcalloc(dev,
- pdata->num_row_gpios + pdata->num_col_gpios,
+ nrow + ncol,
sizeof(unsigned int),
GFP_KERNEL);
if (!gpios) {
@@ -452,12 +452,19 @@ matrix_keypad_parse_dt(struct device *dev)
return ERR_PTR(-ENOMEM);
}
- for (i = 0; i < pdata->num_row_gpios; i++)
- gpios[i] = of_get_named_gpio(np, "row-gpios", i);
+ for (i = 0; i < nrow; i++) {
+ ret = of_get_named_gpio(np, "row-gpios", i);
+ if (ret < 0)
+ return ERR_PTR(ret);
+ gpios[i] = ret;
+ }
- for (i = 0; i < pdata->num_col_gpios; i++)
- gpios[pdata->num_row_gpios + i] =
- of_get_named_gpio(np, "col-gpios", i);
+ for (i = 0; i < ncol; i++) {
+ ret = of_get_named_gpio(np, "col-gpios", i);
+ if (ret < 0)
+ return ERR_PTR(ret);
+ gpios[nrow + i] = ret;
+ }
pdata->row_gpios = gpios;
pdata->col_gpios = &gpios[pdata->num_row_gpios];
@@ -485,7 +492,6 @@ static int matrix_keypad_probe(struct platform_device *pdev)
if (!pdata) {
pdata = matrix_keypad_parse_dt(&pdev->dev);
if (IS_ERR(pdata)) {
- dev_err(&pdev->dev, "no platform data defined\n");
return PTR_ERR(pdata);
}
} else if (!pdata->keymap_data) {
--
2.16.1.2.g9d582f143
