[PATCH] i2c: Fix error value returned by several bus drivers

[Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>]

When adding checks for ACPI resource conflicts to many bus drivers,
not enough attention was paid to the error paths, and for several
drivers this causes 0 to be returned on error in some cases. Fix this
by properly returning a non-zero value on every error.

Signed-off-by: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>
Cc: stable-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org
---
Problem was noticed while reviewing Corentin's i2c-ali1535 patch.
Anyone using these drivers is welcome to test and confirm that I did
not break anything. I'll rebase Corentin's patch on top of this.

 drivers/i2c/busses/i2c-ali1535.c |   11 +++++++----
 drivers/i2c/busses/i2c-nforce2.c |    2 +-
 drivers/i2c/busses/i2c-sis5595.c |    4 ++--
 drivers/i2c/busses/i2c-sis630.c  |    6 +++++-
 drivers/i2c/busses/i2c-viapro.c  |    7 +++++--
 5 files changed, 20 insertions(+), 10 deletions(-)

--- linux-3.2-rc3.orig/drivers/i2c/busses/i2c-ali1535.c	2011-11-25 09:03:07.000000000 +0100
+++ linux-3.2-rc3/drivers/i2c/busses/i2c-ali1535.c	2011-11-25 09:05:32.000000000 +0100
@@ -140,7 +140,7 @@ static unsigned short ali1535_smba;
    defined to make the transition easier. */
 static int __devinit ali1535_setup(struct pci_dev *dev)
 {
-	int retval = -ENODEV;
+	int retval;
 	unsigned char temp;
 
 	/* Check the following things:
@@ -155,6 +155,7 @@ static int __devinit ali1535_setup(struc
 	if (ali1535_smba == 0) {
 		dev_warn(&dev->dev,
 			"ALI1535_smb region uninitialized - upgrade BIOS?\n");
+		retval = -ENODEV;
 		goto exit;
 	}
 
@@ -167,6 +168,7 @@ static int __devinit ali1535_setup(struc
 			    ali1535_driver.name)) {
 		dev_err(&dev->dev, "ALI1535_smb region 0x%x already in use!\n",
 			ali1535_smba);
+		retval = -EBUSY;
 		goto exit;
 	}
 
@@ -174,6 +176,7 @@ static int __devinit ali1535_setup(struc
 	pci_read_config_byte(dev, SMBCFG, &temp);
 	if ((temp & ALI1535_SMBIO_EN) == 0) {
 		dev_err(&dev->dev, "SMB device not enabled - upgrade BIOS?\n");
+		retval = -ENODEV;
 		goto exit_free;
 	}
 
@@ -181,6 +184,7 @@ static int __devinit ali1535_setup(struc
 	pci_read_config_byte(dev, SMBHSTCFG, &temp);
 	if ((temp & 1) == 0) {
 		dev_err(&dev->dev, "SMBus controller not enabled - upgrade BIOS?\n");
+		retval = -ENODEV;
 		goto exit_free;
 	}
 
@@ -198,12 +202,11 @@ static int __devinit ali1535_setup(struc
 	dev_dbg(&dev->dev, "SMBREV = 0x%X\n", temp);
 	dev_dbg(&dev->dev, "ALI1535_smba = 0x%X\n", ali1535_smba);
 
-	retval = 0;
-exit:
-	return retval;
+	return 0;
 
 exit_free:
 	release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
+exit:
 	return retval;
 }
 
--- linux-3.2-rc3.orig/drivers/i2c/busses/i2c-nforce2.c	2011-07-22 04:17:23.000000000 +0200
+++ linux-3.2-rc3/drivers/i2c/busses/i2c-nforce2.c	2011-11-25 09:10:48.000000000 +0100
@@ -356,7 +356,7 @@ static int __devinit nforce2_probe_smb (
 	error = acpi_check_region(smbus->base, smbus->size,
 				  nforce2_driver.name);
 	if (error)
-		return -1;
+		return error;
 
 	if (!request_region(smbus->base, smbus->size, nforce2_driver.name)) {
 		dev_err(&smbus->adapter.dev, "Error requesting region %02x .. %02X for %s\n",
--- linux-3.2-rc3.orig/drivers/i2c/busses/i2c-sis5595.c	2011-07-22 04:17:23.000000000 +0200
+++ linux-3.2-rc3/drivers/i2c/busses/i2c-sis5595.c	2011-11-25 09:12:44.000000000 +0100
@@ -147,7 +147,7 @@ static int __devinit sis5595_setup(struc
 	u16 a;
 	u8 val;
 	int *i;
-	int retval = -ENODEV;
+	int retval;
 
 	/* Look for imposters */
 	for (i = blacklist; *i != 0; i++) {
@@ -223,7 +223,7 @@ static int __devinit sis5595_setup(struc
 
 error:
 	release_region(sis5595_base + SMB_INDEX, 2);
-	return retval;
+	return -ENODEV;
 }
 
 static int sis5595_transaction(struct i2c_adapter *adap)
--- linux-3.2-rc3.orig/drivers/i2c/busses/i2c-sis630.c	2011-07-22 04:17:23.000000000 +0200
+++ linux-3.2-rc3/drivers/i2c/busses/i2c-sis630.c	2011-11-25 09:17:46.000000000 +0100
@@ -393,7 +393,7 @@ static int __devinit sis630_setup(struct
 {
 	unsigned char b;
 	struct pci_dev *dummy = NULL;
-	int retval = -ENODEV, i;
+	int retval, i;
 
 	/* check for supported SiS devices */
 	for (i=0; supported[i] > 0 ; i++) {
@@ -418,18 +418,21 @@ static int __devinit sis630_setup(struct
 	*/
 	if (pci_read_config_byte(sis630_dev, SIS630_BIOS_CTL_REG,&b)) {
 		dev_err(&sis630_dev->dev, "Error: Can't read bios ctl reg\n");
+		retval = -ENODEV;
 		goto exit;
 	}
 	/* if ACPI already enabled , do nothing */
 	if (!(b & 0x80) &&
 	    pci_write_config_byte(sis630_dev, SIS630_BIOS_CTL_REG, b | 0x80)) {
 		dev_err(&sis630_dev->dev, "Error: Can't enable ACPI\n");
+		retval = -ENODEV;
 		goto exit;
 	}
 
 	/* Determine the ACPI base address */
 	if (pci_read_config_word(sis630_dev,SIS630_ACPI_BASE_REG,&acpi_base)) {
 		dev_err(&sis630_dev->dev, "Error: Can't determine ACPI base address\n");
+		retval = -ENODEV;
 		goto exit;
 	}
 
@@ -445,6 +448,7 @@ static int __devinit sis630_setup(struct
 			    sis630_driver.name)) {
 		dev_err(&sis630_dev->dev, "SMBus registers 0x%04x-0x%04x already "
 			"in use!\n", acpi_base + SMB_STS, acpi_base + SMB_SAA);
+		retval = -EBUSY;
 		goto exit;
 	}
 
--- linux-3.2-rc3.orig/drivers/i2c/busses/i2c-viapro.c	2011-07-22 04:17:23.000000000 +0200
+++ linux-3.2-rc3/drivers/i2c/busses/i2c-viapro.c	2011-11-25 09:22:31.000000000 +0100
@@ -324,7 +324,7 @@ static int __devinit vt596_probe(struct
 				 const struct pci_device_id *id)
 {
 	unsigned char temp;
-	int error = -ENODEV;
+	int error;
 
 	/* Determine the address of the SMBus areas */
 	if (force_addr) {
@@ -390,6 +390,7 @@ found:
 			dev_err(&pdev->dev, "SMBUS: Error: Host SMBus "
 				"controller not enabled! - upgrade BIOS or "
 				"use force=1\n");
+			error = -ENODEV;
 			goto release_region;
 		}
 	}
@@ -422,9 +423,11 @@ found:
 		 "SMBus Via Pro adapter at %04x", vt596_smba);
 
 	vt596_pdev = pci_dev_get(pdev);
-	if (i2c_add_adapter(&vt596_adapter)) {
+	error = i2c_add_adapter(&vt596_adapter);
+	if (error) {
 		pci_dev_put(vt596_pdev);
 		vt596_pdev = NULL;
+		goto release_region;
 	}
 
 	/* Always return failure here.  This is to allow other drivers to bind


-- 
Jean Delvare