Re: [PATCH v4] usb: typec: intel_pmc_mux: Expose IOM port status to debugfs

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, May 22, 2023 at 12:33:43PM +0530, Rajat Khandelwal wrote:
> IOM status has a crucial role during debugging to check the
> current state of the type-C port.
> There are ways to fetch the status, but all those require the
> IOM port status offset, which could change with platform.
> 
> Make a debugfs directory for intel_pmc_mux and expose the status
> under it per port basis.
> 
> Signed-off-by: Rajat Khandelwal <rajat.khandelwal@linux.intel.com>
> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> ---
> 
> v4:
> 1. Maintain a root directory for PMC module and incorporate devices
> under it
> 2. Add the debugfs module under '/sys/kernel/debug/usb'
> 3. Use the platform device 'pmc->dev' to assign the device's name
> 
> v3: Allocate the debugfs directory name for the platform device with
> its ACPI dev name included
> 
> v2:
> 1. Remove static declaration of the debugfs root for 'intel_pmc_mux'
> 2. Remove explicitly defined one-liner functions
> 
>  drivers/usb/typec/mux/intel_pmc_mux.c | 54 ++++++++++++++++++++++++++-
>  1 file changed, 53 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/typec/mux/intel_pmc_mux.c b/drivers/usb/typec/mux/intel_pmc_mux.c
> index 34e4188a40ff..f400094c76f2 100644
> --- a/drivers/usb/typec/mux/intel_pmc_mux.c
> +++ b/drivers/usb/typec/mux/intel_pmc_mux.c
> @@ -15,6 +15,8 @@
>  #include <linux/usb/typec_mux.h>
>  #include <linux/usb/typec_dp.h>
>  #include <linux/usb/typec_tbt.h>
> +#include <linux/debugfs.h>
> +#include <linux/usb.h>
>  
>  #include <asm/intel_scu_ipc.h>
>  
> @@ -143,8 +145,14 @@ struct pmc_usb {
>  	struct acpi_device *iom_adev;
>  	void __iomem *iom_base;
>  	u32 iom_port_status_offset;
> +
> +#ifdef CONFIG_DEBUG_FS
> +	struct dentry *dentry;
> +#endif

No need for the #ifdef anymore, right?  In fact, I think it will break
the build if you have it this way and CONFIG_DEBUG_FS is not enabled,
right?

thanks,

greg k-h