| From e0dd6709b01e8fc405617023c251d2fd81b974e9 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Wed, 4 Jul 2018 08:46:07 +0300 |
| Subject: thunderbolt: Use 32-bit writes when writing ring producer/consumer |
| |
| From: Mika Westerberg <mika.westerberg@linux.intel.com> |
| |
| [ Upstream commit 943795219d3cb9f8ce6ce51cad3ffe1f61e95c6b ] |
| |
| 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@linux.intel.com> |
| Reviewed-by: Yehezkel Bernat <YehezkelShB@gmail.com> |
| Tested-by: Mario Limonciello <mario.limonciello@dell.com> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/thunderbolt/nhi.c | 22 ++++++++++++++++++---- |
| 1 file changed, 18 insertions(+), 4 deletions(-) |
| |
| diff --git a/drivers/thunderbolt/nhi.c b/drivers/thunderbolt/nhi.c |
| index 27fbe62c7ddd4..9c782706e652f 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; |
| -- |
| 2.20.1 |
| |