[PATCH v3] drm/i915/gvt: Make correct handling to vreg BXT_PHY_CTL_FAMILY

[He, Min]

Looks good to me. Thanks.
Reviewed-by: He, Min <min.he at intel.com>

On 8/20/2018 4:46 PM, Colin Xu wrote:
> Guest kernel will write to BXT_PHY_CTL_FAMILY to reset DDI PHY
> and pull BXT_PHY_CTL to check PHY status. Previous handling will
> set/reset BXT_PHY_CTL of all PHYs at same time on receiving vreg
> write to some BXT_PHY_CTL_FAMILY. If some BXT_PHY_CTL is already
> enabled, following reset to another BXT_PHY_CTL_FAMILY will clear
> the enabled BXT_PHY_CTL, which result in guest kernel print:
>
> -----------------------------------
> [drm:intel_ddi_get_hw_state [i915]]
> *ERROR* Port B enabled but PHY powered down? (PHY_CTL 00000000)
> -----------------------------------
>
> The correct handling should operate BXT_PHY_CTL_FAMILY and
> BXT_PHY_CTL on the same DDI.
>
> v2: Use correct reg define. The naming looks confusing, however
>      current i915_reg.h bind DPIO_PHY0 to _PHY_CTL_FAMILY_DDI and
>      bind DPIO_PHY1 to _PHY_CTL_FAMILY_EDP, pairing to
>      _BXT_PHY_CTL_DDI_A and _BXT_PHY_CTL_DDI_B respectively.
> v3: v2 incorrectly map _PHY_CTL_FAMILY_EDP to _BXT_PHY_CTL_DDI_A.
>      BXT_PHY_CTL() looks up DDI using PORTx but not PHYx. Based on
>      DPIO_PHY to DDI mapping, make correct vreg handle to BXT_PHY_CTL
>      on receiving vreg write to BXT_PHY_CTL_FAMILY. (He, Min)
>
> Current mapping according to bxt_power_wells:
> dpio-common-a:
>      >>> DPIO_PHY1
>      >>> BXT_DPIO_CMN_A_POWER_DOMAINS
>      >>> POWER_DOMAIN_PORT_DDI_A_LANES
>      >>> PORT_A
>
> dpio-common-bc:
>      >>> DPIO_PHY0
>      >>> BXT_DPIO_CMN_BC_POWER_DOMAINS
>      >>> POWER_DOMAIN_PORT_DDI_B_LANES | POWER_DOMAIN_PORT_DDI_C_LANES
>      >>> PORT_B or PORT_C
>
> Signed-off-by: Colin Xu <colin.xu at intel.com>
> ---
>   drivers/gpu/drm/i915/gvt/handlers.c | 12 +++++++++---
>   1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gvt/handlers.c b/drivers/gpu/drm/i915/gvt/handlers.c
> index b47986a22332..44bdfb596e7d 100644
> --- a/drivers/gpu/drm/i915/gvt/handlers.c
> +++ b/drivers/gpu/drm/i915/gvt/handlers.c
> @@ -1526,9 +1526,15 @@ static int bxt_phy_ctl_family_write(struct intel_vgpu *vgpu,
>   	u32 v = *(u32 *)p_data;
>   	u32 data = v & COMMON_RESET_DIS ? BXT_PHY_LANE_ENABLED : 0;
>   
> -	vgpu_vreg(vgpu, _BXT_PHY_CTL_DDI_A) = data;
> -	vgpu_vreg(vgpu, _BXT_PHY_CTL_DDI_B) = data;
> -	vgpu_vreg(vgpu, _BXT_PHY_CTL_DDI_C) = data;
> +	switch (offset) {
> +	case _PHY_CTL_FAMILY_EDP:
> +		vgpu_vreg(vgpu, _BXT_PHY_CTL_DDI_A) = data;
> +		break;
> +	case _PHY_CTL_FAMILY_DDI:
> +		vgpu_vreg(vgpu, _BXT_PHY_CTL_DDI_B) = data;
> +		vgpu_vreg(vgpu, _BXT_PHY_CTL_DDI_C) = data;
> +		break;
> +	}
>   
>   	vgpu_vreg(vgpu, offset) = v;
>