linux-kernel - [PATCH 3/8] thunderbolt: Use 32-bit writes when writing ring producer/consumer

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Date:   Fri,  5 Jul 2019 12:57:55 +0300
From:   Mika Westerberg <mika.westerberg@...ux.intel.com>
To:     linux-kernel@...r.kernel.org
Cc:     Andreas Noever <andreas.noever@...il.com>,
        Michael Jamet <michael.jamet@...el.com>,
        Yehezkel Bernat <YehezkelShB@...il.com>,
        "Rafael J . Wysocki" <rjw@...ysocki.net>,
        Len Brown <lenb@...nel.org>, Lukas Wunner <lukas@...ner.de>,
        Mario.Limonciello@...l.com,
        Anthony Wong <anthony.wong@...onical.com>,
        Mika Westerberg <mika.westerberg@...ux.intel.com>,
        linux-acpi@...r.kernel.org
Subject: [PATCH 3/8] thunderbolt: Use 32-bit writes when writing ring producer/consumer

The register access should be using 32-bit reads/writes according to the
datasheet. With the previous generation hardware 16-bit writes have been
working but starting with ICL this is not the case anymore so fix
producer/consumer register update to use correct width register address.

Signed-off-by: Mika Westerberg <mika.westerberg@...ux.intel.com>
---
 drivers/thunderbolt/nhi.c | 26 ++++++++++++++++++++++----
 1 file changed, 22 insertions(+), 4 deletions(-)

diff --git a/drivers/thunderbolt/nhi.c b/drivers/thunderbolt/nhi.c
index 27fbe62c7ddd..09242653da67 100644
--- a/drivers/thunderbolt/nhi.c
+++ b/drivers/thunderbolt/nhi.c
@@ -143,9 +143,24 @@ static void __iomem *ring_options_base(struct tb_ring *ring)
 	return io;
 }
 
-static void ring_iowrite16desc(struct tb_ring *ring, u32 value, u32 offset)
+static void ring_iowrite_prod(struct tb_ring *ring, u16 prod)
 {
-	iowrite16(value, ring_desc_base(ring) + offset);
+	u32 val;
+
+	val = ioread32(ring_desc_base(ring) + 8);
+	val &= 0x0000ffff;
+	val |= prod << 16;
+	iowrite32(val, ring_desc_base(ring) + 8);
+}
+
+static void ring_iowrite_cons(struct tb_ring *ring, u16 cons)
+{
+	u32 val;
+
+	val = ioread32(ring_desc_base(ring) + 8);
+	val &= 0xffff0000;
+	val |= cons;
+	iowrite32(val, ring_desc_base(ring) + 8);
 }
 
 static void ring_iowrite32desc(struct tb_ring *ring, u32 value, u32 offset)
@@ -197,7 +212,10 @@ static void ring_write_descriptors(struct tb_ring *ring)
 			descriptor->sof = frame->sof;
 		}
 		ring->head = (ring->head + 1) % ring->size;
-		ring_iowrite16desc(ring, ring->head, ring->is_tx ? 10 : 8);
+		if (ring->is_tx)
+			ring_iowrite_prod(ring, ring->head);
+		else
+			ring_iowrite_cons(ring, ring->head);
 	}
 }
 
@@ -662,7 +680,7 @@ void tb_ring_stop(struct tb_ring *ring)
 
 	ring_iowrite32options(ring, 0, 0);
 	ring_iowrite64desc(ring, 0, 0);
-	ring_iowrite16desc(ring, 0, ring->is_tx ? 10 : 8);
+	ring_iowrite32desc(ring, 0, 8);
 	ring_iowrite32desc(ring, 0, 12);
 	ring->head = 0;
 	ring->tail = 0;
-- 
2.20.1