Commit 9831960d authored by Niklas Neronin's avatar Niklas Neronin Committed by Greg Kroah-Hartman
Browse files

xhci: rework 'xhci_try_enable_msi()' MSI and MSI-X setup code 



Simplify 'xhci_try_enable_msi()' and reduce unnecessary function calls.

xHCI driver first tries to allocate 'num_online_cpu()' number of MSI-X
vectors, if that fails it falls back to a single MSI vector. There is no
good reason for this, we currently only support a primary interrupter.
However, we are still interested in knowing if there are more vectors
available, which will be utilized once we get secondary interrupter
support.

Call 'pci_alloc_irq_vectors()' once (with MSI-X and MSI flag), instead
of separately for MSI-X and MSI. And accept any number of MSI-X or MSI
vectors between 1 and 'num_online_cpu()'.

Signed-off-by: default avatarNiklas Neronin <niklas.neronin@linux.intel.com>
Signed-off-by: default avatarMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20231201150647.1307406-17-mathias.nyman@linux.intel.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent dfbf4441

drivers/usb/host/xhci-pci.c

+15 −29
Original line number Diff line number Diff line
@@ -116,13 +116,13 @@ static void xhci_cleanup_msix(struct xhci_hcd *xhci) 
	hcd->msix_enabled = 0;

}



/* Try enabling MSI-X with MSI and legacy IRQ as fallback */

static int xhci_try_enable_msi(struct usb_hcd *hcd)

{

	struct pci_dev *pdev = to_pci_dev(hcd->self.controller);

	struct xhci_hcd *xhci = hcd_to_xhci(hcd);

	struct pci_dev  *pdev;

	int ret;



	pdev = to_pci_dev(xhci_to_hcd(xhci)->self.controller);

	/*

	 * Some Fresco Logic host controllers advertise MSI, but fail to

	 * generate interrupts.  Don't even try to enable MSI.
@@ -145,42 +145,28 @@ static int xhci_try_enable_msi(struct usb_hcd *hcd) 
	xhci->nvecs = min(num_online_cpus() + 1,

			  HCS_MAX_INTRS(xhci->hcs_params1));



	xhci->nvecs = pci_alloc_irq_vectors(pdev, xhci->nvecs, xhci->nvecs,

					    PCI_IRQ_MSIX);

	/* TODO: Check with MSI Soc for sysdev */

	xhci->nvecs = pci_alloc_irq_vectors(pdev, 1, xhci->nvecs,

					    PCI_IRQ_MSIX | PCI_IRQ_MSI);

	if (xhci->nvecs < 0) {

		xhci_dbg_trace(xhci, trace_xhci_dbg_init, "Failed to enable MSI-X");

		goto setup_msi;

		xhci_dbg_trace(xhci, trace_xhci_dbg_init,

			       "failed to allocate IRQ vectors");

		goto legacy_irq;

	}



	ret = request_irq(pci_irq_vector(pdev, 0), xhci_msi_irq, 0, "xhci_hcd",

			  xhci_to_hcd(xhci));

	if (ret) {

		xhci_dbg_trace(xhci, trace_xhci_dbg_init, "disable MSI-X interrupt");

		pci_free_irq_vectors(pdev);

		goto setup_msi;

	}

	if (ret)

		goto free_irq_vectors;



	hcd->msi_enabled = 1;

	hcd->msix_enabled = 1;

	hcd->msix_enabled = pdev->msix_enabled;

	return 0;



setup_msi:

	/* TODO: Check with MSI Soc for sysdev */

	xhci->nvecs = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI);

	if (xhci->nvecs < 0) {

		xhci_dbg_trace(xhci, trace_xhci_dbg_init, "failed to allocate MSI entry");

		goto legacy_irq;

	}



	ret = request_irq(pdev->irq, xhci_msi_irq, 0, "xhci_hcd", xhci_to_hcd(xhci));

	if (ret) {

		xhci_dbg_trace(xhci, trace_xhci_dbg_init, "disable MSI interrupt");

free_irq_vectors:

	xhci_dbg_trace(xhci, trace_xhci_dbg_init, "disable %s interrupt",

		       pdev->msix_enabled ? "MSI-X" : "MSI");

	pci_free_irq_vectors(pdev);

		goto legacy_irq;

	}



	hcd->msi_enabled = 1;

	return 0;



legacy_irq:

	if (!pdev->irq) {