[RFC PATCH 11/12] usb: xhci: prepare for multiple interrupters

[Niklas Neronin <niklas.neronin@linux.intel.com>]

The core xhci driver only uses a single interrupter. Prepares the driver
to handle multiple interrupters, although it still uses only one interrupt
for now.

Some initialization, such as IP bit auto-clear and IMODI, was previously
done in xhci_run() (called once per xHCI instance). For simplicity,
move these to xhci_init() to consolidate all interrupter-related setup
in a single place.

Move the ERST dequeue debug message from xhci_run() to the existing ERST
debug message in xhci_set_hc_event_deq(). This function is always called
before xhci_run(), and is called for all interrupters.

This change is necessary to prepare the driver for multiple interrupters.

Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com>
---
 drivers/usb/host/xhci-mem.c |  3 +--
 drivers/usb/host/xhci-pci.c |  4 ++++
 drivers/usb/host/xhci.c     | 13 +------------
 3 files changed, 6 insertions(+), 14 deletions(-)

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 46d977f9e5c5..a6fde127c569 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -2017,8 +2017,7 @@ static void xhci_set_hc_event_deq(struct xhci_hcd *xhci, struct xhci_interrupter
 	/* Don't clear the EHB bit (which is RW1C) because
 	 * there might be more events to service.
 	 */
-	xhci_dbg_trace(xhci, trace_xhci_dbg_init,
-		       "// Write event ring dequeue pointer, preserving EHB bit");
+	xhci_dbg_trace(xhci, trace_xhci_dbg_init, "Write ERST %pad, preserving EHB bit", &deq);
 	xhci_write_64(xhci, deq & ERST_PTR_MASK, &ir->ir_set->erst_dequeue);
 }
 
diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index 585b2f3117b0..ea43b0153430 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -181,6 +181,10 @@ static int xhci_try_enable_msi(struct usb_hcd *hcd)
 
 	hcd->msi_enabled = 1;
 	hcd->msix_enabled = pdev->msix_enabled;
+
+	/* MSI/MSI-X interrupts clear IMAN IP bit automatically */
+	xhci->interrupters[0]->ip_autoclear = true;
+
 	return 0;
 
 free_irq_vectors:
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 329fe9ff19f8..e846ab402d3e 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -573,6 +573,7 @@ static void xhci_init(struct usb_hcd *hcd)
 	xhci_ring_init(xhci, xhci->interrupters[0]->event_ring);
 	xhci_add_interrupter(xhci, 0);
 	xhci->interrupters[0]->isoc_bei_interval = AVOID_BEI_INTERVAL_MAX;
+	xhci_set_interrupter_moderation(xhci->interrupters[0], xhci->imod_interval);
 
 	/* Initializing Compliance Mode Recovery Data If Needed */
 	if (xhci_compliance_mode_recovery_timer_quirk_check()) {
@@ -633,30 +634,18 @@ static int xhci_run_finished(struct xhci_hcd *xhci)
  */
 int xhci_run(struct usb_hcd *hcd)
 {
-	u64 temp_64;
 	int ret;
 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
-	struct xhci_interrupter *ir = xhci->interrupters[0];
 	/* Start the xHCI host controller running only after the USB 2.0 roothub
 	 * is setup.
 	 */
 
 	hcd->uses_new_polling = 1;
-	if (hcd->msi_enabled)
-		ir->ip_autoclear = true;
-
 	if (!usb_hcd_is_primary_hcd(hcd))
 		return xhci_run_finished(xhci);
 
 	xhci_dbg_trace(xhci, trace_xhci_dbg_init, "xhci_run");
 
-	temp_64 = xhci_read_64(xhci, &ir->ir_set->erst_dequeue);
-	temp_64 &= ERST_PTR_MASK;
-	xhci_dbg_trace(xhci, trace_xhci_dbg_init,
-			"ERST deq = 64'h%0lx", (long unsigned int) temp_64);
-
-	xhci_set_interrupter_moderation(ir, xhci->imod_interval);
-
 	if (xhci->quirks & XHCI_NEC_HOST) {
 		struct xhci_command *command;
 
-- 
2.50.1