staging: gpib: ines: Handle gpib_register_driver() errors

The function ines_pcmcia_init_module() can be replaced by calling
pcmcia_register_driver() directly. The error value from this
function is not returned and the previous registering functions
are not unregistered.

The function gpib_register_driver() can fail and similar to
pcmcia_register_driver() function failing, the previous registering
functions are not unregistered.

Replace cb_pcmcia_init_module() with pcmcia_register_driver().
Unregister the gpib and pci register functions if the subsequent
gpib or pcmcia register functions fail and return the error value.
Add pr_err() statements indicating the fail and error value.

Signed-off-by: Nihar Chaithanya <niharchaithanya@gmail.com>
Link: https://lore.kernel.org/r/20241230185633.175690-12-niharchaithanya@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: niharcy

drivers/staging/gpib/ines/ines_gpib.c

@@ -1227,12 +1227,6 @@ static struct pcmcia_driver ines_gpib_cs_driver = {
 	.resume		= ines_gpib_resume,
 };
 
-int ines_pcmcia_init_module(void)
-{
-	pcmcia_register_driver(&ines_gpib_cs_driver);
-	return 0;
-}
-
 void ines_pcmcia_cleanup_module(void)
 {
 	DEBUG(0, "ines_cs: unloading\n");
@@ -1420,28 +1414,86 @@ void ines_pcmcia_detach(gpib_board_t *board)
 
 static int __init ines_init_module(void)
 {
-	int err = 0;
+	int ret;
+
+	ret = pci_register_driver(&ines_pci_driver);
+	if (ret) {
+		pr_err("ines_gpib: pci_register_driver failed: error = %d\n", ret);
+		return ret;
+	}
+
+	ret = gpib_register_driver(&ines_pci_interface, THIS_MODULE);
+	if (ret) {
+		pr_err("ines_gpib: gpib_register_driver failed: error = %d\n", ret);
+		goto err_pci;
+	}
 
-	err = pci_register_driver(&ines_pci_driver);
-	if (err) {
-		pr_err("ines_gpib: pci_driver_register failed!\n");
-		return err;
+	ret = gpib_register_driver(&ines_pci_unaccel_interface, THIS_MODULE);
+	if (ret) {
+		pr_err("ines_gpib: gpib_register_driver failed: error = %d\n", ret);
+		goto err_pci_unaccel;
+	}
+
+	ret = gpib_register_driver(&ines_pci_accel_interface, THIS_MODULE);
+	if (ret) {
+		pr_err("ines_gpib: gpib_register_driver failed: error = %d\n", ret);
+		goto err_pci_accel;
+	}
+
+	ret = gpib_register_driver(&ines_isa_interface, THIS_MODULE);
+	if (ret) {
+		pr_err("ines_gpib: gpib_register_driver failed: error = %d\n", ret);
+		goto err_isa;
 	}
 
-	gpib_register_driver(&ines_pci_interface, THIS_MODULE);
-	gpib_register_driver(&ines_pci_unaccel_interface, THIS_MODULE);
-	gpib_register_driver(&ines_pci_accel_interface, THIS_MODULE);
-	gpib_register_driver(&ines_isa_interface, THIS_MODULE);
 #ifdef GPIB_PCMCIA
-	gpib_register_driver(&ines_pcmcia_interface, THIS_MODULE);
-	gpib_register_driver(&ines_pcmcia_unaccel_interface, THIS_MODULE);
-	gpib_register_driver(&ines_pcmcia_accel_interface, THIS_MODULE);
-	err += ines_pcmcia_init_module();
+	ret = gpib_register_driver(&ines_pcmcia_interface, THIS_MODULE);
+	if (ret) {
+		pr_err("ines_gpib: gpib_register_driver failed: error = %d\n", ret);
+		goto err_pcmcia;
+	}
+
+	ret = gpib_register_driver(&ines_pcmcia_unaccel_interface, THIS_MODULE);
+	if (ret) {
+		pr_err("ines_gpib: gpib_register_driver failed: error = %d\n", ret);
+		goto err_pcmcia_unaccel;
+	}
+
+	ret = gpib_register_driver(&ines_pcmcia_accel_interface, THIS_MODULE);
+	if (ret) {
+		pr_err("ines_gpib: gpib_register_driver failed: error = %d\n", ret);
+		goto err_pcmcia_accel;
+	}
+
+	ret = pcmcia_register_driver(&ines_gpib_cs_driver);
+	if (ret) {
+		pr_err("ines_gpib: pcmcia_register_driver failed: error = %d\n", ret);
+		goto err_pcmcia_driver;
+	}
 #endif
-	if (err)
-		return -1;
 
 	return 0;
+
+#ifdef GPIB_PCMCIA
+err_pcmcia_driver:
+	gpib_unregister_driver(&ines_pcmcia_accel_interface);
+err_pcmcia_accel:
+	gpib_unregister_driver(&ines_pcmcia_unaccel_interface);
+err_pcmcia_unaccel:
+	gpib_unregister_driver(&ines_pcmcia_interface);
+err_pcmcia:
+#endif
+	gpib_unregister_driver(&ines_isa_interface);
+err_isa:
+	gpib_unregister_driver(&ines_pci_accel_interface);
+err_pci_accel:
+	gpib_unregister_driver(&ines_pci_unaccel_interface);
+err_pci_unaccel:
+	gpib_unregister_driver(&ines_pci_interface);
+err_pci:
+	pci_unregister_driver(&ines_pci_driver);
+
+	return ret;
 }
 
 static void __exit ines_exit_module(void)