03.01.2020 10:58, Michał Mirosław пишет:

On Sat, Dec 28, 2019 at 11:33:52PM +0300, Dmitry Osipenko wrote:
[...]

quoted

 static int ulpi_open(struct tegra_usb_phy *phy)
 {
-	int err;
-
-	err = gpio_direction_output(phy->reset_gpio, 0);
-	if (err) {
-		dev_err(phy->u_phy.dev,
-			"ULPI reset GPIO %d direction not deasserted: %d\n",
-			phy->reset_gpio, err);
-		return err;
-	}
+	gpiod_set_value_cansleep(phy->reset_gpio, 1);
 
 	return 0;
 }

The message now removed seems inverted to the meaning of the code. Is
this a bug, or the reset really should be asserted here?

The removed message was added in patch #2 and indeed it should say
"asserted". Good catch, thanks!

I can see that
it is deasserted in phy_power_up, but that goes before or after ulpi_open()?

The ulpi_phy_power_on happens after the ulpi_open, please take a look at
tegra_usb_phy_init().

After the change below, the reset is asserted at probe() time now.

Yes, the probe now asserts the reset. It is an intended change because
it should be a bit better to explicitly per-initialize the GPIO state to
an expected state during of the GPIO retrieval, like most of other
drivers do and which should be a "generic/common way".

Actually, the reset assertion of ulpi_open() could be removed safely now
since it doesn't do anything useful, given that probe asserts the reset.

[...]

quoted

-		err = devm_gpio_request(&pdev->dev, tegra_phy->reset_gpio,
-					"ulpi_phy_reset_b");
+		gpiod = devm_gpiod_get_from_of_node(&pdev->dev, np,
+						    "nvidia,phy-reset-gpio",
+						    0, GPIOD_OUT_HIGH,
+						    "ulpi_phy_reset_b");
+		err = PTR_ERR_OR_ZERO(gpiod);
 		if (err) {
-			dev_err(&pdev->dev, "Request failed for GPIO %d: %d\n",
-				tegra_phy->reset_gpio, err);
+			dev_err(&pdev->dev,
+				"Request failed for reset GPIO: %d\n", err);
 			return err;
 		}
+		tegra_phy->reset_gpio = gpiod;

A nice extension to kernel's printf - "%pe" format - has just landed in
Linus' master tree.

Thank you very much, I didn't know about that.

I'll prepare v4 with the above things addressed, thank you again and
please let me know if you'll spot anything else!