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

Sonika Jindal
2015-07-13T08:50:30Z

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)
v3: Add comment about the WA, move 'hpd' initialization outside for
loop (Siva)
Also, remove few redundant comments from hpd handler (me)

Signed-off-by: Sonika Jindal <sonika.jindal@intel.com>
---
drivers/gpu/drm/i915/i915_irq.c | 46 ++++++++++++++++++++++++++-------------
1 file changed, 31 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index a897f68..13cabca 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -88,7 +88,14 @@ static const u32 hpd_status_i915[HPD_NUM_PINS] = {
[HPD_PORT_D] = PORTD_HOTPLUG_INT_STATUS
};

-/* BXT hpd list */
+/*
+ * On BXT A0/A1, sw needs to activate DDIA HPD logic and interrupts to check
+ * the external panel connection. 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
@@ -1967,6 +1974,7 @@ 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;
@@ -1981,7 +1989,12 @@ 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);
}

@@ -3021,31 +3034,34 @@ static void bxt_hpd_irq_setup(struct drm_device *dev)
struct intel_encoder *intel_encoder;
u32 hotplug_port = 0;
u32 hotplug_ctrl;
+ const u32 *hpd;

- /* Now, enable HPD */
- for_each_intel_encoder(dev, intel_encoder) {
+ if (INTEL_REVID(dev) < BXT_REVID_B0)
+ hpd = hpd_bxt_a0;
+ else
+ hpd = hpd_bxt;
+
+ 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];
- }
+ hotplug_port |= hpd[intel_encoder->hpd_pin];

- /* Mask all HPD control bits */
hotplug_ctrl = I915_READ(BXT_HOTPLUG_CTL) & ~BXT_HOTPLUG_CTL_MASK;

- /* 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;
+ 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 */
hotplug_ctrl = I915_READ(GEN8_DE_PORT_IMR) & ~hotplug_port;
I915_WRITE(GEN8_DE_PORT_IMR, hotplug_ctrl);

- /* Enable DDI hotplug in IER */
hotplug_ctrl = I915_READ(GEN8_DE_PORT_IER) | hotplug_port;
I915_WRITE(GEN8_DE_PORT_IER, hotplug_ctrl);
POSTING_READ(GEN8_DE_PORT_IER);
--
1.7.10.4