drm/amdgpu: add timeout flush mechanism to update wptr for self interrupt (v2)

outstanding log reaches threshold will trigger IH ring1/2's wptr
reported, that will avoid generating interrupts to ring0 too frequent.
But if ring1/2's wptr hasn't been increased for a long time, the outstanding log
can't reach threshold so that driver can't get latest wptr info and
miss some interrupts.

v2: squash in warning fix

Signed-off-by: Chengming Gui <[email protected]>
Reviewed-by: Feifei Xu <[email protected]>
Acked-by: Felix Kuehling <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>

Author: Chengming Gui

drivers/gpu/drm/amd/amdgpu/navi10_ih.c

@@ -39,6 +39,48 @@
 
 static void navi10_ih_set_interrupt_funcs(struct amdgpu_device *adev);
 
+/**
+ * force_update_wptr_for_self_int - Force update the wptr for self interrupt
+ *
+ * @adev: amdgpu_device pointer
+ * @threshold: threshold to trigger the wptr reporting
+ * @timeout: timeout to trigger the wptr reporting
+ * @enabled: Enable/disable timeout flush mechanism
+ *
+ * threshold input range: 0 ~ 15, default 0,
+ * real_threshold = 2^threshold
+ * timeout input range: 0 ~ 20, default 8,
+ * real_timeout = (2^timeout) * 1024 / (socclk_freq)
+ *
+ * Force update wptr for self interrupt ( >= SIENNA_CICHLID).
+ */
+static void
+force_update_wptr_for_self_int(struct amdgpu_device *adev,
+			       u32 threshold, u32 timeout, bool enabled)
+{
+	u32 ih_cntl, ih_rb_cntl;
+
+	if (adev->asic_type < CHIP_SIENNA_CICHLID)
+		return;
+
+	ih_cntl = RREG32_SOC15(OSSSYS, 0, mmIH_CNTL2);
+	ih_rb_cntl = RREG32_SOC15(OSSSYS, 0, mmIH_RB_CNTL_RING1);
+
+	ih_cntl = REG_SET_FIELD(ih_cntl, IH_CNTL2,
+				SELF_IV_FORCE_WPTR_UPDATE_TIMEOUT, timeout);
+	ih_cntl = REG_SET_FIELD(ih_cntl, IH_CNTL2,
+				SELF_IV_FORCE_WPTR_UPDATE_ENABLE, enabled);
+	ih_rb_cntl = REG_SET_FIELD(ih_rb_cntl, IH_RB_CNTL_RING1,
+				   RB_USED_INT_THRESHOLD, threshold);
+
+	WREG32_SOC15(OSSSYS, 0, mmIH_RB_CNTL_RING1, ih_rb_cntl);
+	ih_rb_cntl = RREG32_SOC15(OSSSYS, 0, mmIH_RB_CNTL_RING2);
+	ih_rb_cntl = REG_SET_FIELD(ih_rb_cntl, IH_RB_CNTL_RING2,
+				   RB_USED_INT_THRESHOLD, threshold);
+	WREG32_SOC15(OSSSYS, 0, mmIH_RB_CNTL_RING2, ih_rb_cntl);
+	WREG32_SOC15(OSSSYS, 0, mmIH_CNTL2, ih_cntl);
+}
+
 /**
  * navi10_ih_enable_interrupts - Enable the interrupt ring buffer
  *
@@ -371,6 +413,8 @@ static int navi10_ih_irq_init(struct amdgpu_device *adev)
 
 	/* enable interrupts */
 	navi10_ih_enable_interrupts(adev);
+	/* enable wptr force update for self int */
+	force_update_wptr_for_self_int(adev, 0, 8, true);
 
 	return 0;
 }
@@ -384,6 +428,7 @@ static int navi10_ih_irq_init(struct amdgpu_device *adev)
  */
 static void navi10_ih_irq_disable(struct amdgpu_device *adev)
 {
+	force_update_wptr_for_self_int(adev, 0, 8, false);
 	navi10_ih_disable_interrupts(adev);
 
 	/* Wait and acknowledge irq */