Hi,
On Sun, Nov 11, 2018 at 09:44:28PM +0100, Christian Hoff wrote:
> "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. This does not lead to information loss because the other
> error paths in matrix_keypad_parse_dt() already print an error.
>
> Signed-off-by: Christian Hoff <christian_hoff@xxxxxxx>
> Suggested-by: Sebastian Reichel <sre@xxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> ---
Looks good to me.
Reviewed-by: Sebastian Reichel <sre@xxxxxxxxxx>
-- Sebastian
> drivers/input/keyboard/matrix_keypad.c | 23 ++++++++++++++---------
> 1 file changed, 14 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/input/keyboard/matrix_keypad.c b/drivers/input/keyboard/matrix_keypad.c
> index f51ae09596ef..403452ef00e6 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");
> @@ -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];
> @@ -484,10 +491,8 @@ static int matrix_keypad_probe(struct platform_device *pdev)
> pdata = dev_get_platdata(&pdev->dev);
> if (!pdata) {
> pdata = matrix_keypad_parse_dt(&pdev->dev);
> - if (IS_ERR(pdata)) {
> - dev_err(&pdev->dev, "no platform data defined\n");
> + if (IS_ERR(pdata))
> return PTR_ERR(pdata);
> - }
> } else if (!pdata->keymap_data) {
> dev_err(&pdev->dev, "no keymap data defined\n");
> return -EINVAL;
> --
> 2.16.1.2.g9d582f143
>
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