[PATCH v2 1/4] thunderbolt: Intel controller uses BIT(2) for intr auto

[Sanjay R Mehta <Sanju.Mehta@xxxxxxx>]

From: Sanjay R Mehta <sanju.mehta@xxxxxxx>

REG_DMA_MISC_INT_AUTO_CLEAR which is bit 2 in that register is
actually Intel specific.

As per the USB4 spec bit 17 is used for interrupt auto clear and
by default its enabled.

Hence limit usage of REG_DMA_MISC_INT_AUTO_CLEAR for Intel controllers
and moved this to quirk.

Fixes: 046bee1f9ab8 ("thunderbolt: Add MSI-X support")
Suggested-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@xxxxxxx>
Signed-off-by: Sanjay R Mehta <sanju.mehta@xxxxxxx>
---
 drivers/thunderbolt/nhi.c    |  8 ++------
 drivers/thunderbolt/quirks.c | 14 ++++++++++++++
 drivers/thunderbolt/tb.h     |  1 +
 3 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/drivers/thunderbolt/nhi.c b/drivers/thunderbolt/nhi.c
index fa44332..ef01aa6 100644
--- a/drivers/thunderbolt/nhi.c
+++ b/drivers/thunderbolt/nhi.c
@@ -57,8 +57,8 @@ static void ring_interrupt_active(struct tb_ring *ring, bool active)
 	u32 old, new;
 
 	if (ring->irq > 0) {
-		u32 step, shift, ivr, misc;
 		void __iomem *ivr_base;
+		u32 step, shift, ivr;
 		int index;
 
 		if (ring->is_tx)
@@ -70,11 +70,7 @@ static void ring_interrupt_active(struct tb_ring *ring, bool active)
 		 * Ask the hardware to clear interrupt status bits automatically
 		 * since we already know which interrupt was triggered.
 		 */
-		misc = ioread32(ring->nhi->iobase + REG_DMA_MISC);
-		if (!(misc & REG_DMA_MISC_INT_AUTO_CLEAR)) {
-			misc |= REG_DMA_MISC_INT_AUTO_CLEAR;
-			iowrite32(misc, ring->nhi->iobase + REG_DMA_MISC);
-		}
+		quirk_enable_intr_auto_clr(ring);
 
 		ivr_base = ring->nhi->iobase + REG_INT_VEC_ALLOC_BASE;
 		step = index / REG_INT_VEC_ALLOC_REGS * REG_INT_VEC_ALLOC_BITS;
diff --git a/drivers/thunderbolt/quirks.c b/drivers/thunderbolt/quirks.c
index b5f2ec7..af6dab9 100644
--- a/drivers/thunderbolt/quirks.c
+++ b/drivers/thunderbolt/quirks.c
@@ -6,6 +6,7 @@
  */
 
 #include "tb.h"
+#include "nhi_regs.h"
 
 static void quirk_force_power_link(struct tb_switch *sw)
 {
@@ -64,3 +65,16 @@ void tb_check_quirks(struct tb_switch *sw)
 		q->hook(sw);
 	}
 }
+
+void quirk_enable_intr_auto_clr(struct tb_ring *ring)
+{
+	u32 misc;
+
+	if (ring->nhi->pdev->vendor == PCI_VENDOR_ID_INTEL) {
+		misc = ioread32(ring->nhi->iobase + REG_DMA_MISC);
+		if (!(misc & REG_DMA_MISC_INT_AUTO_CLEAR)) {
+			misc |= REG_DMA_MISC_INT_AUTO_CLEAR;
+			iowrite32(misc, ring->nhi->iobase + REG_DMA_MISC);
+		}
+	}
+}
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index 725104c..0b8f9d3 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -1122,6 +1122,7 @@ int usb4_port_device_resume(struct usb4_port *usb4);
 #define QUIRK_FORCE_POWER_LINK_CONTROLLER		BIT(0)
 
 void tb_check_quirks(struct tb_switch *sw);
+void quirk_enable_intr_auto_clr(struct tb_ring *ring);
 
 #ifdef CONFIG_ACPI
 void tb_acpi_add_links(struct tb_nhi *nhi);
-- 
2.7.4