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i2c-ali1563: Fix device initialization
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The i2c-ali1563 initialization looks quite broken to me:
* If the I/O space isn't enabled, we forcibly set 3 bits in
  the PCI configuration space instead of just the one enabling
  the I/O space.
* After that we pretend to check if the write worked, but we
  don't actually read the new value from the register.
* It's probably not a good idea to enable the I/O space if no
  base address has been set.

So I propose the following changes to that part of the driver:
* Merge ali1563_enable() into ali1563_setup().
* Check the base address before the I/O space enabled bit.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Rudolf Marek <r.marek@assembler.cz>
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Jean Delvare authored and Jean Delvare committed Feb 13, 2007
1 parent 6973569 commit 849be51
Showing 1 changed file with 18 additions and 23 deletions.
41 changes: 18 additions & 23 deletions drivers/i2c/busses/i2c-ali1563.c
Original file line number Diff line number Diff line change
Expand Up @@ -314,42 +314,37 @@ static u32 ali1563_func(struct i2c_adapter * a)
}


static void ali1563_enable(struct pci_dev * dev)
{
u16 ctrl;

pci_read_config_word(dev,ALI1563_SMBBA,&ctrl);
ctrl |= 0x7;
pci_write_config_word(dev,ALI1563_SMBBA,ctrl);
}

static int __devinit ali1563_setup(struct pci_dev * dev)
{
u16 ctrl;

pci_read_config_word(dev,ALI1563_SMBBA,&ctrl);

/* Check if device is even enabled first */
if (!(ctrl & ALI1563_SMB_IOEN)) {
dev_warn(&dev->dev,"I/O space not enabled, trying manually\n");
ali1563_enable(dev);
}
if (!(ctrl & ALI1563_SMB_IOEN)) {
dev_warn(&dev->dev,"I/O space still not enabled, giving up\n");
goto Err;
}
if (!(ctrl & ALI1563_SMB_HOSTEN)) {
dev_warn(&dev->dev,"Host Controller not enabled\n");
goto Err;
}

/* SMB I/O Base in high 12 bits and must be aligned with the
* size of the I/O space. */
ali1563_smba = ctrl & ~(ALI1563_SMB_IOSIZE - 1);
if (!ali1563_smba) {
dev_warn(&dev->dev,"ali1563_smba Uninitialized\n");
goto Err;
}

/* Check if device is enabled */
if (!(ctrl & ALI1563_SMB_HOSTEN)) {
dev_warn(&dev->dev, "Host Controller not enabled\n");
goto Err;
}
if (!(ctrl & ALI1563_SMB_IOEN)) {
dev_warn(&dev->dev, "I/O space not enabled, trying manually\n");
pci_write_config_word(dev, ALI1563_SMBBA,
ctrl | ALI1563_SMB_IOEN);
pci_read_config_word(dev, ALI1563_SMBBA, &ctrl);
if (!(ctrl & ALI1563_SMB_IOEN)) {
dev_err(&dev->dev, "I/O space still not enabled, "
"giving up\n");
goto Err;
}
}

if (!request_region(ali1563_smba, ALI1563_SMB_IOSIZE,
ali1563_pci_driver.name)) {
dev_err(&dev->dev, "Could not allocate I/O space at 0x%04x\n",
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