Re: [PATCH 2/3] watchdog: iTCO_wdt: Make ICH_RES_IO_SMI optional

Mika Westerberg
2020-02-25T14:42:57Z

On Tue, Feb 25, 2020 at 06:37:09AM -0800, Guenter Roeck wrote:
> On Tue, Feb 25, 2020 at 03:38:01PM +0300, Mika Westerberg wrote:
> > The iTCO_wdt driver only needs ICH_RES_IO_SMI I/O resource when either
> > turn_SMI_watchdog_clear_off module parameter is set to match ->iTCO_version
> > (or higher), and when legacy iTCO_vendorsupport is set. Modify the driver
> > so that ICH_RES_IO_SMI is optional if the two conditions are not met.
> >
> > Signed-off-by: Mika Westerberg <mika.westerberg-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> > ---
> > drivers/watchdog/iTCO_wdt.c | 22 +++++++++++++---------
> > 1 file changed, 13 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/watchdog/iTCO_wdt.c b/drivers/watchdog/iTCO_wdt.c
> > index 156360e37714..f1692452bc25 100644
> > --- a/drivers/watchdog/iTCO_wdt.c
> > +++ b/drivers/watchdog/iTCO_wdt.c
> > @@ -460,7 +460,7 @@ static int iTCO_wdt_probe(struct platform_device *pdev)
> > return -ENODEV;
> >
> > p->smi_res = platform_get_resource(pdev, IORESOURCE_IO, ICH_RES_IO_SMI);
> > - if (!p->smi_res)
> > + if (!p->smi_res && iTCO_vendorsupport)
> > return -ENODEV;
> >
> > p->iTCO_version = pdata->version;
> > @@ -492,15 +492,19 @@ static int iTCO_wdt_probe(struct platform_device *pdev)
> > /* Set the NO_REBOOT bit to prevent later reboots, just for sure */
> > p->update_no_reboot_bit(p->no_reboot_priv, true);
> >
> > - /* The TCO logic uses the TCO_EN bit in the SMI_EN register */
> > - if (!devm_request_region(dev, p->smi_res->start,
> > - resource_size(p->smi_res),
> > - pdev->name)) {
> > - pr_err("I/O address 0x%04llx already in use, device disabled\n",
> > - (u64)SMI_EN(p));
> > - return -EBUSY;
> > - }
> > if (turn_SMI_watchdog_clear_off >= p->iTCO_version) {
> > + if (!p->smi_res) {
> > + pr_err("SMI I/O resource is missing\n");
> > + return -EINVAL;
> > + }
> > + /* The TCO logic uses the TCO_EN bit in the SMI_EN register */
> > + if (!devm_request_region(dev, p->smi_res->start,
> > + resource_size(p->smi_res),
> > + pdev->name)) {
> > + pr_err("I/O address 0x%04llx already in use, device disabled\n",
> > + (u64)SMI_EN(p));
> > + return -EBUSY;
> > + }
>
> The request_region call is also needed if iTCO_vendorsupport is true.
> Well, not strictly speaking, I guess, but then one could argue that
> it isn't needed at all.

Indeed, this is good point as well. Will be fixed in v2.

> In this context - looking into the vendorsupport code, I wonder if
> it is time to retire it. Separate patch, of course, but still.
> Any thoughts ?

No objections from me ;-)