i2c-parport: Give powered devices some time to settle

When the i2c-parport adapter is reponsible for powering devices, it
would seem reasonable to give them some time to settle before trying
to access them.

Signed-off-by: Jean Delvare <khali@linux-fr.org>

2 files changed, 10 insertions, 2 deletions

diff --git a/drivers/i2c/busses/i2c-parport-light.c b/drivers/i2c/busses/i2c-parport-light.c
index 322c5691e38e..5383f64c5372 100644
--- a/drivers/i2c/busses/i2c-parport-light.c
+++ b/drivers/i2c/busses/i2c-parport-light.c
@@ -27,6 +27,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
+#include <linux/delay.h>
 #include <linux/platform_device.h>
 #include <linux/ioport.h>
 #include <linux/i2c.h>
@@ -127,8 +128,11 @@ static int __devinit i2c_parport_probe(struct platform_device *pdev)
         parport_setsda(NULL, 1);
         parport_setscl(NULL, 1);
         /* Other init if needed (power on...) */
-        if (adapter_parm[type].init.val)
+        if (adapter_parm[type].init.val) {
                 line_set(1, &adapter_parm[type].init);
+                /* Give powered devices some time to settle */
+                msleep(100);
+        }
 
         parport_adapter.dev.parent = &pdev->dev;
         err = i2c_bit_add_bus(&parport_adapter);
diff --git a/drivers/i2c/busses/i2c-parport.c b/drivers/i2c/busses/i2c-parport.c
index 0d8998610c74..056af1820993 100644
--- a/drivers/i2c/busses/i2c-parport.c
+++ b/drivers/i2c/busses/i2c-parport.c
@@ -27,6 +27,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
+#include <linux/delay.h>
 #include <linux/parport.h>
 #include <linux/i2c.h>
 #include <linux/i2c-algo-bit.h>
@@ -185,8 +186,11 @@ static void i2c_parport_attach (struct parport *port)
         parport_setsda(port, 1);
         parport_setscl(port, 1);
         /* Other init if needed (power on...) */
-        if (adapter_parm[type].init.val)
+        if (adapter_parm[type].init.val) {
                 line_set(port, 1, &adapter_parm[type].init);
+                /* Give powered devices some time to settle */
+                msleep(100);
+        }
 
         if (i2c_bit_add_bus(&adapter->adapter) < 0) {
                 printk(KERN_ERR "i2c-parport: Unable to register with I2C\n");