Commit 944e7deb authored by Josue David Hernandez Gutierrez's avatar Josue David Hernandez Gutierrez Committed by Greg Kroah-Hartman
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xhci: Avoid PCI MSI/MSIX interrupt reinitialization at resume 



xhci MSI setup is currently done at the same time as xHC host is started
in xhci_run(). This couples the generic xhci code with PCI, and will
reconfigure MSI/MSIX interrupts every time xHC is started.

Decouple MSI/MSIX configuration from generic xhci code by moving MSI/MSIX
part to a PCI specific xhci_pci_run() function overriding xhci_run().

This allows us to remove unnecessay MSI/MSIX reconfiguration done every
time PCI xhci resumes from suspend. i.e. remove the xhci_cleanup_msix()
call from xhci_resume() and the xhci_try_enale_msi() call in xhci_run()
called a bit later by xhci_resume()

[minor changes and commit message rewrite -Mathias]

Signed-off-by: default avatarJosue David Hernandez Gutierrez <josue.d.hernandez.gutierrez@intel.com>
Signed-off-by: default avatarMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20230317154715.535523-10-mathias.nyman@linux.intel.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent edf1664f

drivers/usb/host/xhci-pci.c

+15 −0
Original line number Diff line number Diff line
@@ -78,14 +78,29 @@ static const char hcd_name[] = "xhci_hcd"; 
static struct hc_driver __read_mostly xhci_pci_hc_driver;



static int xhci_pci_setup(struct usb_hcd *hcd);

static int xhci_pci_run(struct usb_hcd *hcd);

static int xhci_pci_update_hub_device(struct usb_hcd *hcd, struct usb_device *hdev,

				      struct usb_tt *tt, gfp_t mem_flags);



static const struct xhci_driver_overrides xhci_pci_overrides __initconst = {

	.reset = xhci_pci_setup,

	.start = xhci_pci_run,

	.update_hub_device = xhci_pci_update_hub_device,

};



static int xhci_pci_run(struct usb_hcd *hcd)

{

	int ret;



	if (usb_hcd_is_primary_hcd(hcd)) {

		ret = xhci_try_enable_msi(hcd);

		if (ret)

			return ret;

	}



	return xhci_run(hcd);

}



/* called after powerup, by probe or system-pm "wakeup" */

static int xhci_pci_reinit(struct xhci_hcd *xhci, struct pci_dev *pdev)

{

drivers/usb/host/xhci.c

+2 −6
Original line number Diff line number Diff line
@@ -432,7 +432,7 @@ static void __maybe_unused xhci_msix_sync_irqs(struct xhci_hcd *xhci) 
	}

}



static int xhci_try_enable_msi(struct usb_hcd *hcd)

int xhci_try_enable_msi(struct usb_hcd *hcd)

{

	struct xhci_hcd *xhci = hcd_to_xhci(hcd);

	struct pci_dev  *pdev;
@@ -486,6 +486,7 @@ static int xhci_try_enable_msi(struct usb_hcd *hcd) 
	hcd->irq = pdev->irq;

	return 0;

}

EXPORT_SYMBOL_GPL(xhci_try_enable_msi);



#else
@@ -701,10 +702,6 @@ int xhci_run(struct usb_hcd *hcd) 


	xhci_dbg_trace(xhci, trace_xhci_dbg_init, "xhci_run");



	ret = xhci_try_enable_msi(hcd);

	if (ret)

		return ret;



	temp_64 = xhci_read_64(xhci, &ir->ir_set->erst_dequeue);

	temp_64 &= ~ERST_PTR_MASK;

	xhci_dbg_trace(xhci, trace_xhci_dbg_init,
@@ -1246,7 +1243,6 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated) 
		spin_unlock_irq(&xhci->lock);

		if (retval)

			return retval;

		xhci_cleanup_msix(xhci);



		xhci_dbg(xhci, "// Disabling event ring interrupts\n");

		temp = readl(&xhci->op_regs->status);

drivers/usb/host/xhci.h

+1 −0
Original line number Diff line number Diff line
@@ -2143,6 +2143,7 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated); 


irqreturn_t xhci_irq(struct usb_hcd *hcd);

irqreturn_t xhci_msi_irq(int irq, void *hcd);

int xhci_try_enable_msi(struct usb_hcd *hcd);

int xhci_alloc_dev(struct usb_hcd *hcd, struct usb_device *udev);

int xhci_alloc_tt_info(struct xhci_hcd *xhci,

		struct xhci_virt_device *virt_dev,