Re: [PATCH] xhci: use pm_ptr() instead of #ifdef for CONFIG_PM conditionals

[Mathias Nyman <mathias.nyman@linux.intel.com>]

On 28.3.2023 16.10, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> A recent patch caused an unused-function warning in builds with
> CONFIG_PM disabled, after the function became marked 'static':
> 
> drivers/usb/host/xhci-pci.c:91:13: error: 'xhci_msix_sync_irqs' defined but not used [-Werror=unused-function]
>     91 | static void xhci_msix_sync_irqs(struct xhci_hcd *xhci)
>        |             ^~~~~~~~~~~~~~~~~~~
> 
> This could be solved by adding another #ifdef, but as there is
> a trend towards removing CONFIG_PM checks in favor of helper
> macros, do the same conversion here and use pm_ptr() to get
> either a function pointer or NULL but avoid the warning.
> 
> As the hidden functions reference some other symbols, make
> sure those are visible at compile time, at the minimal cost of
> a few extra bytes for 'struct usb_device'.
> 
> Fixes: 9abe15d55dcc ("xhci: Move xhci MSI sync function to to xhci-pci")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Thanks for this.
Looks like Greg already picked it.

-Mathias