On Sun, Nov 01, 2015 at 05:32:07PM +0100, Christian Fetzer wrote:
> Request the SMBus base address index region once in piix4_probe. This
> is particularly useful when using the multiplexed adapter in SB800 as
> it avoids requesting and releasing the region on every transfer.
>
> Signed-off-by: Christian Fetzer <fetzer.ch@xxxxxxxxx>
> ---
> drivers/i2c/busses/i2c-piix4.c | 35 ++++++++++++++++++++++-------------
> 1 file changed, 22 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c
> index 35eeb0d..d866b58 100644
> --- a/drivers/i2c/busses/i2c-piix4.c
> +++ b/drivers/i2c/busses/i2c-piix4.c
> @@ -125,6 +125,9 @@ static const struct dmi_system_id piix4_dmi_ibm[] = {
> { },
> };
>
> +/* SB800 globals */
> +static unsigned short piix4_smb_idx_sb800;
> +
> struct i2c_piix4_adapdata {
> unsigned short smba;
> };
> @@ -232,7 +235,6 @@ static int piix4_setup_sb800(struct pci_dev *PIIX4_dev,
> const struct pci_device_id *id, u8 aux)
> {
> unsigned short piix4_smba;
> - unsigned short smba_idx = 0xcd6;
> u8 smba_en_lo, smba_en_hi, smb_en, smb_en_status;
> u8 i2ccfg, i2ccfg_offset = 0x10;
>
> @@ -254,16 +256,10 @@ static int piix4_setup_sb800(struct pci_dev *PIIX4_dev,
> else
> smb_en = (aux) ? 0x28 : 0x2c;
>
> - if (!request_region(smba_idx, 2, "smba_idx")) {
> - dev_err(&PIIX4_dev->dev, "SMBus base address index region "
> - "0x%x already in use!\n", smba_idx);
> - return -EBUSY;
> - }
> - outb_p(smb_en, smba_idx);
> - smba_en_lo = inb_p(smba_idx + 1);
> - outb_p(smb_en + 1, smba_idx);
> - smba_en_hi = inb_p(smba_idx + 1);
> - release_region(smba_idx, 2);
> + outb_p(smb_en, piix4_smb_idx_sb800);
> + smba_en_lo = inb_p(piix4_smb_idx_sb800 + 1);
> + outb_p(smb_en + 1, piix4_smb_idx_sb800);
> + smba_en_hi = inb_p(piix4_smb_idx_sb800 + 1);
>
> if (!smb_en) {
> smb_en_status = smba_en_lo & 0x10;
> @@ -616,16 +612,26 @@ static int piix4_add_adapter(struct pci_dev *dev, unsigned short smba,
>
> static int piix4_probe(struct pci_dev *dev, const struct pci_device_id *id)
> {
> + unsigned short smba_idx = 0xcd6;
> int retval;
>
> if ((dev->vendor == PCI_VENDOR_ID_ATI &&
> dev->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS &&
> dev->revision >= 0x40) ||
> - dev->vendor == PCI_VENDOR_ID_AMD)
> + dev->vendor == PCI_VENDOR_ID_AMD) {
> +
> + if (!request_region(smba_idx, 2, "smba_idx")) {
> + dev_err(&dev->dev, "SMBus base address index region "
> + "0x%x already in use!\n", smba_idx);
> + return -EBUSY;
> + }
> + piix4_smb_idx_sb800 = smba_idx;
If I read this right, piix4_smb_idx_sb800 will always be 0xcd6. Why do
you need the global variable at all then? Why not have constant like
below?
#define SB800_PIIX4_SMB_IDX 0xcd6
--
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