#define QUIRK_AUTO_CLEAR_INT BIT(0)
#define QUIRK_E2E BIT(1)
-static int ring_interrupt_index(struct tb_ring *ring)
+static int ring_interrupt_index(const struct tb_ring *ring)
{
int bit = ring->hop;
if (!ring->is_tx)
{
int reg = REG_RING_INTERRUPT_BASE +
ring_interrupt_index(ring) / 32 * 4;
- int bit = ring_interrupt_index(ring) & 31;
- int mask = 1 << bit;
+ int interrupt_bit = ring_interrupt_index(ring) & 31;
+ int mask = 1 << interrupt_bit;
u32 old, new;
if (ring->irq > 0) {
u32 step, shift, ivr, misc;
void __iomem *ivr_base;
+ int auto_clear_bit;
int index;
if (ring->is_tx)
else
index = ring->hop + ring->nhi->hop_count;
- if (ring->nhi->quirks & QUIRK_AUTO_CLEAR_INT) {
- /*
- * 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);
- }
- }
+ /*
+ * Intel routers support a bit that isn't part of
+ * the USB4 spec to ask the hardware to clear
+ * interrupt status bits automatically since
+ * we already know which interrupt was triggered.
+ *
+ * Other routers explicitly disable auto-clear
+ * to prevent conditions that may occur where two
+ * MSIX interrupts are simultaneously active and
+ * reading the register clears both of them.
+ */
+ misc = ioread32(ring->nhi->iobase + REG_DMA_MISC);
+ if (ring->nhi->quirks & QUIRK_AUTO_CLEAR_INT)
+ auto_clear_bit = REG_DMA_MISC_INT_AUTO_CLEAR;
+ else
+ auto_clear_bit = REG_DMA_MISC_DISABLE_AUTO_CLEAR;
+ if (!(misc & auto_clear_bit))
+ iowrite32(misc | auto_clear_bit,
+ ring->nhi->iobase + REG_DMA_MISC);
ivr_base = ring->nhi->iobase + REG_INT_VEC_ALLOC_BASE;
step = index / REG_INT_VEC_ALLOC_REGS * REG_INT_VEC_ALLOC_BITS;
dev_dbg(&ring->nhi->pdev->dev,
"%s interrupt at register %#x bit %d (%#x -> %#x)\n",
- active ? "enabling" : "disabling", reg, bit, old, new);
+ active ? "enabling" : "disabling", reg, interrupt_bit, old, new);
if (new == old)
dev_WARN(&ring->nhi->pdev->dev,
static void ring_clear_msix(const struct tb_ring *ring)
{
+ int bit;
+
if (ring->nhi->quirks & QUIRK_AUTO_CLEAR_INT)
return;
+ bit = ring_interrupt_index(ring) & 31;
if (ring->is_tx)
- ioread32(ring->nhi->iobase + REG_RING_NOTIFY_BASE);
+ iowrite32(BIT(bit), ring->nhi->iobase + REG_RING_INT_CLEAR);
else
- ioread32(ring->nhi->iobase + REG_RING_NOTIFY_BASE +
- 4 * (ring->nhi->hop_count / 32));
+ iowrite32(BIT(bit), ring->nhi->iobase + REG_RING_INT_CLEAR +
+ 4 * (ring->nhi->hop_count / 32));
}
static irqreturn_t ring_msix(int irq, void *data)
ring->hop);
ret = -EBUSY;
goto err_unlock;
- } else if (!ring->is_tx && nhi->rx_rings[ring->hop]) {
+ }
+ if (!ring->is_tx && nhi->rx_rings[ring->hop]) {
dev_warn(&nhi->pdev->dev, "RX hop %d already allocated\n",
ring->hop);
ret = -EBUSY;