[PATCH 2/4] thunderbolt: Handle INTR when Disable ISR auto clear bit set

Sanjay R Mehta
2021-08-02T12:58:51Z

From: Sanjay R Mehta <sanju.mehta@amd.com>

when the "Disable ISR Auto-Clear" bit is set, the Tx/Rx ring
interrupt status is not cleared. Hence handling it by setting
the "Interrupt status clear" register to clear the
corresponding Tx/Rx ring interrupt.

Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
Signed-off-by: Sanjay R Mehta <sanju.mehta@amd.com>
---
drivers/thunderbolt/nhi.c | 26 +++++++++++++++++++++++++-
include/linux/thunderbolt.h | 1 +
2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/drivers/thunderbolt/nhi.c b/drivers/thunderbolt/nhi.c
index d7d9c4b..63bbabf 100644
--- a/drivers/thunderbolt/nhi.c
+++ b/drivers/thunderbolt/nhi.c
@@ -74,7 +74,11 @@ static void ring_interrupt_active(struct tb_ring *ring, bool active)
if (!(misc & REG_DMA_MISC_INT_AUTO_CLEAR)) {
misc |= REG_DMA_MISC_INT_AUTO_CLEAR;
iowrite32(misc, ring->nhi->iobase + REG_DMA_MISC);
- }
+ misc = ioread32(ring->nhi->iobase + REG_DMA_MISC);
+ if (misc & REG_DMA_MISC_INT_AUTO_CLEAR)
+ ring->nhi->is_intr_autoclr = true;
+ } else
+ ring->nhi->is_intr_autoclr = true;

ivr_base = ring->nhi->iobase + REG_INT_VEC_ALLOC_BASE;
step = index / REG_INT_VEC_ALLOC_REGS * REG_INT_VEC_ALLOC_BITS;
@@ -377,11 +381,31 @@ void tb_ring_poll_complete(struct tb_ring *ring)
}
EXPORT_SYMBOL_GPL(tb_ring_poll_complete);

+static void check_and_clear_intr_status(struct tb_ring *ring, int int_pos)
+{
+ u32 value;
+
+ if (!ring->nhi->is_intr_autoclr) {
+ value = ioread32(ring->nhi->iobase
+ + REG_RING_NOTIFY_BASE
+ + 4 * (int_pos / 32));
+ iowrite32(value, ring->nhi->iobase
+ + (REG_RING_NOTIFY_BASE + 8)
+ + 4 * (int_pos / 32));
+ }
+}
+
static irqreturn_t ring_msix(int irq, void *data)
{
struct tb_ring *ring = data;

spin_lock(&ring->nhi->lock);
+
+ if (ring->is_tx)
+ check_and_clear_intr_status(ring, 0);
+ else
+ check_and_clear_intr_status(ring, ring->nhi->hop_count);
+
spin_lock(&ring->lock);
__ring_interrupt(ring);
spin_unlock(&ring->lock);
diff --git a/include/linux/thunderbolt.h b/include/linux/thunderbolt.h
index e7c96c3..bbe7c7e 100644
--- a/include/linux/thunderbolt.h
+++ b/include/linux/thunderbolt.h
@@ -478,6 +478,7 @@ struct tb_nhi {
struct tb_ring **rx_rings;
struct ida msix_ida;
bool going_away;
+ bool is_intr_autoclr;
struct work_struct interrupt_work;
u32 hop_count;
};
--
2.7.4