6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Niklas Neronin [ Upstream commit 70651cc3f5a4c7cec529f121e36ea3b45ea84778 ] The Structural Parameters 1 (HCSPARAMS1) register is read and cached in 'xhci->hcs_params1' during host controller initialization. Since this register is read-only and its value remains constant for the lifetime of the controller, re-reading it later is unnecessary. Replace subsequent register reads with the cached 'xhci->hcs_params1' value to avoid redundant MMIO access. Signed-off-by: Niklas Neronin Signed-off-by: Mathias Nyman Link: https://patch.msgid.link/20251119142417.2820519-15-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman Stable-dep-of: 78203d5b54a4 ("usb: xhci: bail out of setup if the controller is inaccessible") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/xhci.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -4253,8 +4253,7 @@ int xhci_alloc_dev(struct usb_hcd *hcd, xhci_err(xhci, "Error while assigning device slot ID: %s\n", xhci_trb_comp_code_string(command->status)); xhci_err(xhci, "Max number of devices this xHCI host supports is %u.\n", - HCS_MAX_SLOTS( - readl(&xhci->cap_regs->hcs_params1))); + HCS_MAX_SLOTS(xhci->hcs_params1)); xhci_free_command(xhci, command); return 0; }