[PATCH AUTOSEL 6.3 08/24] xhci: Avoid PCI MSI/MSIX interrupt reinitialization at resume

Sasha Levin
2023-05-07T00:31:11Z

From: Josue David Hernandez Gutierrez <josue.d.hernandez.gutierrez@intel.com>

[ Upstream commit 944e7deb4238d10cd16905474574236ac8a8e847 ]

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: Josue David Hernandez Gutierrez <josue.d.hernandez.gutierrez@intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20230317154715.535523-10-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/usb/host/xhci-pci.c | 15 +++++++++++++++
drivers/usb/host/xhci.c | 8 ++------
drivers/usb/host/xhci.h | 1 +
3 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index 6db07ca419c31..8060782a2367d 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -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)
{
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 6307bae9cddff..f498df6b02c80 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -436,7 +436,7 @@ 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;
@@ -490,6 +490,7 @@ static int xhci_try_enable_msi(struct usb_hcd *hcd)
hcd->irq = pdev->irq;
return 0;
}
+EXPORT_SYMBOL_GPL(xhci_try_enable_msi);

#else

@@ -705,10 +706,6 @@ 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,
@@ -1250,7 +1247,6 @@ 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);
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 786002bb35db0..26fccc8d90556 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -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,
--
2.39.2