Re: [PATCH 5/6] ACPI / LPSS: return no error from register_device_clock in special cases

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Wednesday, March 27, 2013 10:58:01 AM Andy Shevchenko wrote:
> When device uses the fixed clock and has no private space of LTR, we have to
> create main LPSS clock and register platform device. This is normally a case
> for LPSS DMA controller.
> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
>  drivers/acpi/acpi_lpss.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c
> index b1c9542..4015929 100644
> --- a/drivers/acpi/acpi_lpss.c
> +++ b/drivers/acpi/acpi_lpss.c
> @@ -95,6 +95,10 @@ static int register_device_clock(struct acpi_device *adev,
>  	if (!lpss_clk_dev)
>  		lpt_register_clock_device();
>  
> +	if (!dev_desc->prv_offset && dev_desc->clk_required)

If clk_required is not set, register_device_clock() won't be called at all for
the device.  Moreover, prv_offset may be zero in principle.

You'd need to add support for shared clocks for that to really work.  I have code
for that, please ping me off-list.

> +		/* There is no error when device uses fixed clock */
> +		return 0;
> +
>  	if (!dev_desc->clk_parent || !pdata->mmio_base
>  	    || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
>  		return -ENODATA;

Thanks,
Rafael


-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.