[PATCH 25/33] usb: xhci: request MSI/-X according to requested amount

[Mathias Nyman <mathias.nyman@linux.intel.com>]

From: Niklas Neronin <niklas.neronin@linux.intel.com>

Variable 'max_interrupters' contains the maximum supported interrupters
or the maximum interrupters the user has requested. Thus, it should be
used instead of HCS_MAX_INTRS().

User set 'max_interrupters' value is validated in xhci_gen_setup(),
otherwise 'max_interrupters' value is 'HCS_MAX_INTRS(xhci->hcs_params1)'.

Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
---
 drivers/usb/host/xhci-pci.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index b1f4dd3f9eff..47c4f70793e4 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -149,14 +149,11 @@ static int xhci_try_enable_msi(struct usb_hcd *hcd)
 	hcd->irq = 0;
 
 	/*
-	 * calculate number of MSI-X vectors supported.
-	 * - HCS_MAX_INTRS: the max number of interrupts the host can handle,
-	 *   with max number of interrupters based on the xhci HCSPARAMS1.
-	 * - num_online_cpus: maximum MSI-X vectors per CPUs core.
-	 *   Add additional 1 vector to ensure always available interrupt.
+	 * Calculate number of MSI/MSI-X vectors supported.
+	 * - max_interrupters: the max number of interrupts requested, capped to xhci HCSPARAMS1.
+	 * - num_online_cpus: one vector per CPUs core, with at least one overall.
 	 */
-	xhci->nvecs = min(num_online_cpus() + 1,
-			  HCS_MAX_INTRS(xhci->hcs_params1));
+	xhci->nvecs = min(num_online_cpus() + 1, xhci->max_interrupters);
 
 	/* TODO: Check with MSI Soc for sysdev */
 	xhci->nvecs = pci_alloc_irq_vectors(pdev, 1, xhci->nvecs,
-- 
2.25.1