On Thu, Mar 25, 2021 at 10:09:47AM +0100, Roger Pau Monne wrote:
> Use the value read from the REVID register in order to check for the
> presence of the device. A read of all ones is treated as if the device
> is not present, and hence probing is ended.
>
> This fixes an issue when running as a Xen PVH dom0, where the ACPI
> DSDT table is provided unmodified to dom0 and hence contains the
> pinctrl devices, but the MMIO region(s) containing the device
> registers might not be mapped in the guest physical memory map if such
> region(s) are not exposed on a PCI device BAR or marked as reserved in
> the host memory map.
Applied for fixes, thanks!
> 91d898e51e60 ('pinctrl: intel: Convert capability list to features')
> Suggested-by: Andy Shevchenko
> Signed-off-by: Roger Pau Monné
> ---
> Changes since v2:
> - Return ENODEV.
> - Adjust code comment.
>
> Changes since v1:
> - New in this version.
> ---
> Cc: Mika Westerberg
> Cc: Andy Shevchenko
> Cc: Linus Walleij
> Cc: linux-g...@vger.kernel.org
> ---
> drivers/pinctrl/intel/pinctrl-intel.c | 7 ++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pinctrl/intel/pinctrl-intel.c
> b/drivers/pinctrl/intel/pinctrl-intel.c
> index 8085782cd8f9..9fc5bba514ea 100644
> --- a/drivers/pinctrl/intel/pinctrl-intel.c
> +++ b/drivers/pinctrl/intel/pinctrl-intel.c
> @@ -1491,8 +1491,13 @@ static int intel_pinctrl_probe(struct platform_device
> *pdev,
> if (IS_ERR(regs))
> return PTR_ERR(regs);
>
> - /* Determine community features based on the revision */
> + /*
> + * Determine community features based on the revision.
> + * A value of all ones means the device is not present.
> + */
> value = readl(regs + REVID);
> + if (value == ~0u)
> + return -ENODEV;
> if (((value & REVID_MASK) >> REVID_SHIFT) >= 0x94) {
> community->features |= PINCTRL_FEATURE_DEBOUNCE;
> community->features |= PINCTRL_FEATURE_1K_PD;
> --
> 2.30.1
>
--
With Best Regards,
Andy Shevchenko
