[PATCH v2] usb: dwc3: meson-g12a: do post init to fix broken usb after resumption

[Luke Lu <luke.lu@libre.computer>]

Device connected to usb otg port of GXL-based boards can not be
recognised after resumption, doesn't recover even if disconnect and
reconnect the device. dmesg shows it disconnects during resumption.

[   41.492911] usb 1-2: USB disconnect, device number 3
[   41.499346] usb 1-2: unregistering device
[   41.511939] usb 1-2: unregistering interface 1-2:1.0

Calling usb_post_init() will fix this issue, and it's tested and
verified on libretech's aml-s905x-cc board.

Cc: stable@vger.kernel.org # v5.8+
Fixes: c99993376f72 ("usb: dwc3: Add Amlogic G12A DWC3 glue")
Signed-off-by: Luke Lu <luke.lu@libre.computer>

---
Note here, the commmit of Fixes tag is the first patch which bring
suspend/resume function, so let's use it as the fix tag.

As commit 5b0ba0caaf3a: (usb: dwc3: meson-g12a: refactor usb init)"
introduced the use_post_init() function, and this patch will explicitly
depend on it, so let's set kernel version higher or equal to v5.8.

Changes since v1:
 - add Fixes tag and Cc stable tree
---
 drivers/usb/dwc3/dwc3-meson-g12a.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/usb/dwc3/dwc3-meson-g12a.c b/drivers/usb/dwc3/dwc3-meson-g12a.c
index e99c7489dba0..2c07c038b584 100644
--- a/drivers/usb/dwc3/dwc3-meson-g12a.c
+++ b/drivers/usb/dwc3/dwc3-meson-g12a.c
@@ -926,6 +926,12 @@ static int __maybe_unused dwc3_meson_g12a_resume(struct device *dev)
 			return ret;
 	}
 
+	if (priv->drvdata->usb_post_init) {
+		ret = priv->drvdata->usb_post_init(priv);
+		if (ret)
+			return ret;
+	}
+
 	return 0;
 }
 
-- 
2.40.1