Re: [PATCH 04/19] drm/i915/vga: Extract intel_gmch_ctrl_reg()

[Jani Nikula <jani.nikula@linux.intel.com>]

On Mon, 08 Dec 2025, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> Extract the GMCH_CTLR register offset determination into a helper
> rather than using a local varaible. I'll be needing this in another
> function soon.
>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

Reviewed-by: Jani Nikula <jani.nikula@intel.com>

> ---
>  drivers/gpu/drm/i915/display/intel_vga.c | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_vga.c b/drivers/gpu/drm/i915/display/intel_vga.c
> index 39c68aec647b..84fd5475d336 100644
> --- a/drivers/gpu/drm/i915/display/intel_vga.c
> +++ b/drivers/gpu/drm/i915/display/intel_vga.c
> @@ -18,6 +18,11 @@
>  #include "intel_vga.h"
>  #include "intel_vga_regs.h"
>  
> +static unsigned int intel_gmch_ctrl_reg(struct intel_display *display)
> +{
> +	return DISPLAY_VER(display) >= 6 ? SNB_GMCH_CTRL : INTEL_GMCH_CTRL;
> +}
> +
>  static i915_reg_t intel_vga_cntrl_reg(struct intel_display *display)
>  {
>  	if (display->platform.valleyview || display->platform.cherryview)
> @@ -98,10 +103,10 @@ void intel_vga_disable(struct intel_display *display)
>  static int intel_gmch_vga_set_state(struct intel_display *display, bool enable_decode)
>  {
>  	struct pci_dev *pdev = to_pci_dev(display->drm->dev);
> -	unsigned int reg = DISPLAY_VER(display) >= 6 ? SNB_GMCH_CTRL : INTEL_GMCH_CTRL;
>  	u16 gmch_ctrl;
>  
> -	if (pci_bus_read_config_word(pdev->bus, PCI_DEVFN(0, 0), reg, &gmch_ctrl)) {
> +	if (pci_bus_read_config_word(pdev->bus, PCI_DEVFN(0, 0),
> +				     intel_gmch_ctrl_reg(display), &gmch_ctrl)) {
>  		drm_err(display->drm, "failed to read control word\n");
>  		return -EIO;
>  	}
> @@ -114,7 +119,8 @@ static int intel_gmch_vga_set_state(struct intel_display *display, bool enable_d
>  	else
>  		gmch_ctrl |= INTEL_GMCH_VGA_DISABLE;
>  
> -	if (pci_bus_write_config_word(pdev->bus, PCI_DEVFN(0, 0), reg, gmch_ctrl)) {
> +	if (pci_bus_write_config_word(pdev->bus, PCI_DEVFN(0, 0),
> +				      intel_gmch_ctrl_reg(display), gmch_ctrl)) {
>  		drm_err(display->drm, "failed to write control word\n");
>  		return -EIO;
>  	}

-- 
Jani Nikula, Intel