Re: [PATCH] drm/i915/bxt: WA for swapped HPD pins in A stepping

Sivakumar Thulasimani
2015-07-13T06:31:44Z

On 7/13/2015 9:47 AM, Sonika Jindal wrote:
> As per bspec, on BXT A0/A1, sw needs to activate DDIA HPD logic
> and interrupts to check the external panel connection.
> And remove the redundant comment.
>
> v2: Remove redundant IS_BROXTON check, Add comment about port C not
> connected, and rephrase the commit message to include only what we
> are doing here (Imre)
>
> Signed-off-by: Sonika Jindal <sonika.jindal@intel.com>
> ---
> drivers/gpu/drm/i915/i915_irq.c | 38 +++++++++++++++++++++++++++++---------
> 1 file changed, 29 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index eb52a03..760539c 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -88,7 +88,11 @@ static const u32 hpd_status_i915[HPD_NUM_PINS] = {
> [HPD_PORT_D] = PORTD_HOTPLUG_INT_STATUS
> };
>
> -/* BXT hpd list */
> +/* Port C is not connected on bxt A0/A1 */
> +static const u32 hpd_bxt_a0[HPD_NUM_PINS] = {
> + [HPD_PORT_B] = BXT_DE_PORT_HP_DDIA
> +};
> +
> static const u32 hpd_bxt[HPD_NUM_PINS] = {
> [HPD_PORT_B] = BXT_DE_PORT_HP_DDIB,
> [HPD_PORT_C] = BXT_DE_PORT_HP_DDIC
> @@ -2257,6 +2261,7 @@ static void bxt_hpd_handler(struct drm_device *dev, uint32_t iir_status)
> struct drm_i915_private *dev_priv = dev->dev_private;
> u32 hp_control, hp_trigger;
> u32 pin_mask, long_mask;
> + const u32 *hpd;
>
> /* Get the status */
> hp_trigger = iir_status & BXT_DE_PORT_HOTPLUG_MASK;
> @@ -2271,7 +2276,12 @@ static void bxt_hpd_handler(struct drm_device *dev, uint32_t iir_status)
> /* Clear sticky bits in hpd status */
> I915_WRITE(BXT_HOTPLUG_CTL, hp_control);
>
> - pch_get_hpd_pins(&pin_mask, &long_mask, hp_trigger, hp_control, hpd_bxt);
> + if (INTEL_REVID(dev) < BXT_REVID_B0)
> + hpd = hpd_bxt_a0;
> + else
> + hpd = hpd_bxt;
> +
> + pch_get_hpd_pins(&pin_mask, &long_mask, hp_trigger, hp_control, hpd);
> intel_hpd_irq_handler(dev, pin_mask, long_mask);
> }
>
> @@ -3315,8 +3325,15 @@ static void bxt_hpd_irq_setup(struct drm_device *dev)
> /* Now, enable HPD */
> for_each_intel_encoder(dev, intel_encoder) {
> if (dev_priv->hotplug.stats[intel_encoder->hpd_pin].state
> - == HPD_ENABLED)
> - hotplug_port |= hpd_bxt[intel_encoder->hpd_pin];
> + == HPD_ENABLED) {
> + const u32 *hpd;
> +
> + if (INTEL_REVID(dev) < BXT_REVID_B0)
> + hpd = hpd_bxt_a0;
> + else
> + hpd = hpd_bxt;
> + hotplug_port |= hpd[intel_encoder->hpd_pin];
> + }
> }
>
hpd initialization can be moved out so it is done once instead of being
repeated for each encoder.

> /* Mask all HPD control bits */
> @@ -3324,11 +3341,14 @@ static void bxt_hpd_irq_setup(struct drm_device *dev)
>
> /* Enable requested port in hotplug control */
> /* TODO: implement (short) HPD support on port A */
> - WARN_ON_ONCE(hotplug_port & BXT_DE_PORT_HP_DDIA);
> - if (hotplug_port & BXT_DE_PORT_HP_DDIB)
> - hotplug_ctrl |= BXT_DDIB_HPD_ENABLE;
> - if (hotplug_port & BXT_DE_PORT_HP_DDIC)
> - hotplug_ctrl |= BXT_DDIC_HPD_ENABLE;
> + if (INTEL_REVID(dev) < BXT_REVID_B0 && (hotplug_port & BXT_DE_PORT_HP_DDIA))
> + hotplug_ctrl |= BXT_DDIA_HPD_ENABLE;
can you add a comment here stating the swap in hpd pins ?
as i am not sure not everyone will first check the commit message for
the change here.
> + else {
> + if (hotplug_port & BXT_DE_PORT_HP_DDIB)
> + hotplug_ctrl |= BXT_DDIB_HPD_ENABLE;
> + if (hotplug_port & BXT_DE_PORT_HP_DDIC)
> + hotplug_ctrl |= BXT_DDIC_HPD_ENABLE;
> + }
> I915_WRITE(BXT_HOTPLUG_CTL, hotplug_ctrl);
>
> /* Unmask DDI hotplug in IMR */
>
>

--
regards,
Sivakumar