[PATCH] staging: gdm724x: fix returning -1 with return equivalent errors

[Rodrigo Gobbi <rodrigo.gobbi.7@gmail.com>]

As in the TODO file, use proper error codes from PM callbacks and init.

Signed-off-by: Rodrigo Gobbi <rodrigo.gobbi.7@gmail.com>
---
Only one reference was left, regarding the packet_type_to_tty_index() but
I think it's reasonable to keep it that way since it's for tty index purpose.

There is a RFC to delete this driver at [1], so I'm not 
sure if this change is worth it. Anyway, I'm submitting 
it and I'll be waiting for an opinion about this.
Tks.

[1] https://lore.kernel.org/lkml/50020db0-3bad-41f5-8da3-c66bc0a90fe6@gmail.com/

 drivers/staging/gdm724x/TODO      | 1 -
 drivers/staging/gdm724x/gdm_mux.c | 4 ++--
 drivers/staging/gdm724x/gdm_usb.c | 6 +++---
 3 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/gdm724x/TODO b/drivers/staging/gdm724x/TODO
index b2b571ecb063..56a415b9dcbe 100644
--- a/drivers/staging/gdm724x/TODO
+++ b/drivers/staging/gdm724x/TODO
@@ -2,7 +2,6 @@ TODO:
 - Clean up coding style to meet kernel standard. (80 line limit, netdev_err)
 - Remove test for host endian
 - Remove confusing macros (endian, hci_send, sdu_send, rcv_with_cb)
-- Fixes for every instances of function returning -1
 - Check for skb->len in gdm_lte_emulate_arp()
 - Use ALIGN() macro for dummy_cnt in up_to_host()
 - Error handling in init_usb()
diff --git a/drivers/staging/gdm724x/gdm_mux.c b/drivers/staging/gdm724x/gdm_mux.c
index 9b12619671a1..456e7cb66f03 100644
--- a/drivers/staging/gdm724x/gdm_mux.c
+++ b/drivers/staging/gdm724x/gdm_mux.c
@@ -594,7 +594,7 @@ static int gdm_mux_suspend(struct usb_interface *intf, pm_message_t pm_msg)
 
 	if (mux_dev->usb_state != PM_NORMAL) {
 		dev_err(intf->usb_dev, "usb suspend - invalid state\n");
-		return -1;
+		return -EINVAL;
 	}
 
 	mux_dev->usb_state = PM_SUSPEND;
@@ -622,7 +622,7 @@ static int gdm_mux_resume(struct usb_interface *intf)
 
 	if (mux_dev->usb_state != PM_SUSPEND) {
 		dev_err(intf->usb_dev, "usb resume - invalid state\n");
-		return -1;
+		return -EINVAL;
 	}
 
 	mux_dev->usb_state = PM_NORMAL;
diff --git a/drivers/staging/gdm724x/gdm_usb.c b/drivers/staging/gdm724x/gdm_usb.c
index 54bdb64f52e8..e4bbab6cb047 100644
--- a/drivers/staging/gdm724x/gdm_usb.c
+++ b/drivers/staging/gdm724x/gdm_usb.c
@@ -916,7 +916,7 @@ static int gdm_usb_suspend(struct usb_interface *intf, pm_message_t pm_msg)
 	rx = &udev->rx;
 	if (udev->usb_state != PM_NORMAL) {
 		dev_err(intf->usb_dev, "usb suspend - invalid state\n");
-		return -1;
+		return -EINVAL;
 	}
 
 	udev->usb_state = PM_SUSPEND;
@@ -952,7 +952,7 @@ static int gdm_usb_resume(struct usb_interface *intf)
 
 	if (udev->usb_state != PM_SUSPEND) {
 		dev_err(intf->usb_dev, "usb resume - invalid state\n");
-		return -1;
+		return -EINVAL;
 	}
 	udev->usb_state = PM_NORMAL;
 
@@ -991,7 +991,7 @@ static int __init gdm_usb_lte_init(void)
 {
 	if (gdm_lte_event_init() < 0) {
 		pr_err("error creating event\n");
-		return -1;
+		return -ENODEV;
 	}
 
 	return usb_register(&gdm_usb_lte_driver);
-- 
2.34.1