[PATCH 2/2] accel/ivpu: Clear specific interrupt status bits on C0

[Stanislaw Gruszka]

From: Karol Wachowski <karol.wachowski at linux.intel.com>

MTL C0 stepping fixed issue related to butrress interrupt status clearing,
to clear an interrupt status it is required to write 1 to specific
status bit field. This allows to execute read, modify and write routine.

Writing 0 will not clear the interrupt and will cause interrupt storm.

Fixes: 35b137630f08 ("accel/ivpu: Introduce a new DRM driver for Intel VPU")
Cc: stable at vger.kernel.org # 6.3.x
Signed-off-by: Karol Wachowski <karol.wachowski at linux.intel.com>
Signed-off-by: Stanislaw Gruszka <stanislaw.gruszka at linux.intel.com>
---
 drivers/accel/ivpu/ivpu_drv.h    |  1 +
 drivers/accel/ivpu/ivpu_hw_mtl.c | 18 ++++++++++++------
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/accel/ivpu/ivpu_drv.h b/drivers/accel/ivpu/ivpu_drv.h
index 315180dd72ce..8fe8cda2e39d 100644
--- a/drivers/accel/ivpu/ivpu_drv.h
+++ b/drivers/accel/ivpu/ivpu_drv.h
@@ -75,6 +75,7 @@ struct ivpu_wa_table {
 	bool punit_disabled;
 	bool clear_runtime_mem;
 	bool d3hot_after_power_off;
+	bool interrupt_clear_with_0;
 };
 
 struct ivpu_hw_info;
diff --git a/drivers/accel/ivpu/ivpu_hw_mtl.c b/drivers/accel/ivpu/ivpu_hw_mtl.c
index d3ba633daaa0..f1211e74017d 100644
--- a/drivers/accel/ivpu/ivpu_hw_mtl.c
+++ b/drivers/accel/ivpu/ivpu_hw_mtl.c
@@ -101,6 +101,9 @@ static void ivpu_hw_wa_init(struct ivpu_device *vdev)
 	vdev->wa.punit_disabled = ivpu_is_fpga(vdev);
 	vdev->wa.clear_runtime_mem = false;
 	vdev->wa.d3hot_after_power_off = true;
+
+	if (ivpu_device_id(vdev) == PCI_DEVICE_ID_MTL && ivpu_revision(vdev) < 4)
+		vdev->wa.interrupt_clear_with_0 = true;
 }
 
 static void ivpu_hw_timeouts_init(struct ivpu_device *vdev)
@@ -962,12 +965,15 @@ static u32 ivpu_hw_mtl_irqb_handler(struct ivpu_device *vdev, int irq)
 		schedule_recovery = true;
 	}
 
-	/*
-	 * Clear local interrupt status by writing 0 to all bits.
-	 * This must be done after interrupts are cleared at the source.
-	 * Writing 1 triggers an interrupt, so we can't perform read update write.
-	 */
-	REGB_WR32(MTL_BUTTRESS_INTERRUPT_STAT, 0x0);
+	/* This must be done after interrupts are cleared at the source. */
+	if (IVPU_WA(interrupt_clear_with_0))
+		/*
+		 * Writing 1 triggers an interrupt, so we can't perform read update write.
+		 * Clear local interrupt status by writing 0 to all bits.
+		 */
+		REGB_WR32(MTL_BUTTRESS_INTERRUPT_STAT, 0x0);
+	else
+		REGB_WR32(MTL_BUTTRESS_INTERRUPT_STAT, status);
 
 	/* Re-enable global interrupt */
 	REGB_WR32(MTL_BUTTRESS_GLOBAL_INT_MASK, 0x0);
-- 
2.25.1