[PATCH] usb: xhci: xhci_setup_port_arrays: early -ENODEV if maxports is 0.

Olivier Dautricourt
2024-09-30T05:23:56Z

If the controller reports HCSPARAMS1.maxports==0 then we can skip the
whole function: it would fail later after doing a bunch of unnecessary
stuff. It can occur on a buggy hardware (the value is driven by external
signals).

Signed-off-by: Olivier Dautricourt <olivierdautricourt@gmail.com>
---
drivers/usb/host/xhci-mem.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index d2900197a49e..e8406db78782 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -2160,6 +2160,11 @@ static int xhci_setup_port_arrays(struct xhci_hcd *xhci, gfp_t flags)
struct device *dev = xhci_to_hcd(xhci)->self.sysdev;

num_ports = HCS_MAX_PORTS(xhci->hcs_params1);
+ if (num_ports == 0) {
+ xhci_warn(xhci, "Host controller has no port enabled\n");
+ return -ENODEV;
+ }
+
xhci->hw_ports = kcalloc_node(num_ports, sizeof(*xhci->hw_ports),
flags, dev_to_node(dev));
if (!xhci->hw_ports)
--
2.43.0