Hi Jean:
* Jean Delvare <khali at linux-fr.org> [2006-04-18 14:06:29 +0200]:
> Fix for bug #6395:
> Fail to resume on Tecra M2 with ADM1032 and Intel 82801DBM
>
> The BIOS of the Tecra M2 doesn't like it when it has to reboot or
> resume after the i2c-i801 driver has left the SMBus in PEC mode. So we
> need to add proper .suspend, .resume and .shutdown callbacks to that
> driver, where we clear and restore the PEC mode bit appropriately.
NACK: saved_auxctl is uninitialized in this patch (what happened to
the patch I looked at last night?)
Also, now that I look at it again... wouldn't it be much easier to just
disable PEC again after every transfer? That's safer too: the call-
backs might not be enough e.g. if the user hits the reset button after
a PEC transfer.
> Thanks to Daniele Gaffuri for the very good report and contribution.
>
> Signed-off-by: Jean Delvare <khali at linux-fr.org>
> ---
> drivers/i2c/busses/i2c-i801.c | 30 ++++++++++++++++++++++++++++++
> 1 file changed, 30 insertions(+)
>
> --- linux-2.6.17-rc1.orig/drivers/i2c/busses/i2c-i801.c 2006-04-18 09:34:15.000000000 +0200
> +++ linux-2.6.17-rc1/drivers/i2c/busses/i2c-i801.c 2006-04-18 12:47:07.000000000 +0200
> @@ -110,6 +110,7 @@
> static struct pci_driver i801_driver;
> static struct pci_dev *I801_dev;
> static int isich4;
> +static u8 saved_auxctl;
>
> static int i801_setup(struct pci_dev *dev)
> {
> @@ -551,17 +552,46 @@
> return i2c_add_adapter(&i801_adapter);
> }
>
> +static void i801_shutdown(struct pci_dev *dev)
> +{
> + if (isich4) {
> + /* Disable PEC mode before leaving, else some BIOSes will
> + fail to resume/reboot. */
> + outb_p(0, SMBAUXCTL);
> + }
> +}
> +
> static void __devexit i801_remove(struct pci_dev *dev)
> {
> i2c_del_adapter(&i801_adapter);
> + i801_shutdown(dev);
> release_region(i801_smba, (isich4 ? 16 : 8));
> }
>
> +static int i801_suspend(struct pci_dev *dev, pm_message_t state)
> +{
> + i801_shutdown(dev);
> + return pci_save_state(dev);
> +}
> +
> +static int i801_resume(struct pci_dev *dev)
> +{
> + pci_restore_state(dev);
> + if (isich4) {
> + /* Restore PEC mode */
> + outb_p(saved_auxctl, SMBAUXCTL);
> + }
> + return 0;
> +}
> +
> static struct pci_driver i801_driver = {
> .name = "i801_smbus",
> .id_table = i801_ids,
> .probe = i801_probe,
> .remove = __devexit_p(i801_remove),
> + .suspend = i801_suspend,
> + .resume = i801_resume,
> + .shutdown = i801_shutdown,
> };
>
> static int __init i2c_i801_init(void)
>
Regards,
--
Mark M. Hoffman
mhoffman at lightlink.com
