From 943795219d3cb9f8ce6ce51cad3ffe1f61e95c6b Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Wed, 4 Jul 2018 08:46:07 +0300 Subject: 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 Reviewed-by: Yehezkel Bernat Tested-by: Mario Limonciello --- drivers/thunderbolt/nhi.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) (limited to 'drivers/thunderbolt/nhi.c') diff --git a/drivers/thunderbolt/nhi.c b/drivers/thunderbolt/nhi.c index 27fbe62c7ddd..9c782706e652 100644 --- a/drivers/thunderbolt/nhi.c +++ b/drivers/thunderbolt/nhi.c @@ -143,9 +143,20 @@ 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_cons(struct tb_ring *ring, u16 cons) { - iowrite16(value, ring_desc_base(ring) + offset); + /* + * The other 16-bits in the register is read-only and writes to it + * are ignored by the hardware so we can save one ioread32() by + * filling the read-only bits with zeroes. + */ + iowrite32(cons, ring_desc_base(ring) + 8); +} + +static void ring_iowrite_prod(struct tb_ring *ring, u16 prod) +{ + /* See ring_iowrite_cons() above for explanation */ + iowrite32(prod << 16, ring_desc_base(ring) + 8); } static void ring_iowrite32desc(struct tb_ring *ring, u32 value, u32 offset) @@ -197,7 +208,10 @@ 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 +676,7 @@ 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; -- cgit v1.2.3