sysfsgpio: give time to udev to change gpio permission

[openocd.git] / src / jtag / drivers / sysfsgpio.c

diff --git a/src/jtag/drivers/sysfsgpio.c b/src/jtag/drivers/sysfsgpio.c
index eb4941e6b241a3852dab87f12ade519116eb85ff..c6ffa3205a15ad6a6d7699c629cb9b8a717c942d 100644 (file)
--- a/src/jtag/drivers/sysfsgpio.c
+++ b/src/jtag/drivers/sysfsgpio.c
@@ -52,6 +52,7 @@
 #include "config.h"
 #endif
 
+#include <helper/time_support.h>
 #include <jtag/interface.h>
 #include "bitbang.h"
 
@@ -112,6 +113,7 @@ static void unexport_sysfs_gpio(int gpio)
  */
 static int setup_sysfs_gpio(int gpio, int is_output, int init_high)
 {
+       struct timeval timeout, now;
        char buf[40];
        char gpiostr[5];
        int ret;
@@ -131,8 +133,19 @@ static int setup_sysfs_gpio(int gpio, int is_output, int init_high)
                }
        }
 
+       gettimeofday(&timeout, NULL);
+       timeval_add_time(&timeout, 0, 500000);
+
        snprintf(buf, sizeof(buf), "/sys/class/gpio/gpio%d/direction", gpio);
-       ret = open_write_close(buf, is_output ? (init_high ? "high" : "low") : "in");
+       for (;;) {
+               ret = open_write_close(buf, is_output ? (init_high ? "high" : "low") : "in");
+               if (ret >= 0 || errno != EACCES)
+                       break;
+               gettimeofday(&now, NULL);
+               if (timeval_compare(&now, &timeout) >= 0)
+                       break;
+               jtag_sleep(10000);
+       }
        if (ret < 0) {
                LOG_ERROR("Couldn't set direction for gpio %d", gpio);
                perror("sysfsgpio: ");
@@ -141,7 +154,15 @@ static int setup_sysfs_gpio(int gpio, int is_output, int init_high)
        }
 
        snprintf(buf, sizeof(buf), "/sys/class/gpio/gpio%d/value", gpio);
-       ret = open(buf, O_RDWR | O_NONBLOCK | O_SYNC);
+       for (;;) {
+               ret = open(buf, O_RDWR | O_NONBLOCK | O_SYNC);
+               if (ret >= 0 || errno != EACCES)
+                       break;
+               gettimeofday(&now, NULL);
+               if (timeval_compare(&now, &timeout) >= 0)
+                       break;
+               jtag_sleep(10000);
+       }
        if (ret < 0) {
                LOG_ERROR("Couldn't open value for gpio %d", gpio);
                perror("sysfsgpio: ");