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Subjectprotected pins and debugfs
Hi All,

This is regarding the protected pins configuration reading and printing
from non-secure operating systems.
GPIO framework is checking whether pin is in use(flag FLAG_REQUESTED) or
not in gpiolib_dbg_show().

If GPIO chip drivers are overriding the dbg_show callback, drivers are
not checking whether a pin is really in use or not to print
configuration details.
if (chip->dbg_show)
chip->dbg_show(s, chip);
gpiolib_dbg_show(s, gdev);

I think, reserved-gpio-ranges solution may move the problem to dts
settings maintenance as they change from platform to platform.

Can we use a simple/common solution like below? It will check whether a
pin is in use or not before printing configuration data with the help of

index fef0970..2ca1440 100644
--- a/drivers/pinctrl/qcom/pinctrl-msm.c
+++ b/drivers/pinctrl/qcom/pinctrl-msm.c
@@ -579,16 +579,20 @@ static void msm_gpio_dbg_show_one(struct seq_file
seq_printf(s, " %-8s: %-3s %d", g->name, is_out ? "out" : "in",
seq_printf(s, " %dmA", msm_regval_to_drive(drive));
seq_printf(s, " %s", pulls[pull]);
+ seq_puts(s, "\n");

static void msm_gpio_dbg_show(struct seq_file *s, struct gpio_chip
unsigned gpio = chip->base;
unsigned i;
+ const char *label;

for (i = 0; i < chip->ngpio; i++, gpio++) {
+ label = gpiochip_is_requested(chip, i);
+ if (!label)
+ continue;
msm_gpio_dbg_show_one(s, NULL, chip, i, gpio);
- seq_puts(s, "\n");

-Thanks, Prasad
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora
Linux Foundation Collaborative Project

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