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usb: xhci: optimize resuming from S4 (suspend-to-disk)

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On resume from S4 (power loss after suspend/hibernation), the xHCI
driver previously freed, reallocated, and fully reinitialized all
data structures. Most of this is unnecessary because the data is
restored from a saved image; only the xHCI registers lose their values.

This patch optimizes S4 resume by performing only a host controller
reset, which includes:
* Freeing or clearing runtime-created data.
* Rewriting xHCI registers.

Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://patch.msgid.link/20260402131342.2628648-13-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Niklas Neronin
2026-04-02 16:13:29 +03:00
committed by Greg Kroah-Hartman
parent 951564d2ca
commit 2a70e5dc03
3 changed files with 35 additions and 24 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/usb/host/xhci-mem.c
View File

@@ -936,7 +936,7 @@ void xhci_free_virt_device(struct xhci_hcd *xhci, struct xhci_virt_device *dev,
* that tt_info, then free the child first. Recursive.
* We can't rely on udev at this point to find child-parent relationships.
*/
static void xhci_free_virt_devices_depth_first(struct xhci_hcd *xhci, int slot_id)
void xhci_free_virt_devices_depth_first(struct xhci_hcd *xhci, int slot_id)
{
struct xhci_virt_device *vdev;
struct list_head *tt_list_head;
@@ -1905,7 +1905,7 @@ void xhci_remove_secondary_interrupter(struct usb_hcd *hcd, struct xhci_interrup
EXPORT_SYMBOL_GPL(xhci_remove_secondary_interrupter);
/* Cleanup roothub bandwidth data */
static void xhci_rh_bw_cleanup(struct xhci_hcd *xhci)
void xhci_rh_bw_cleanup(struct xhci_hcd *xhci)
{
struct xhci_root_port_bw_info *rh_bw;
struct xhci_tt_bw_info *tt_info, *tt_next;

53
drivers/usb/host/xhci.c
View File

@@ -1082,9 +1082,11 @@ int xhci_resume(struct xhci_hcd *xhci, bool power_lost, bool is_auto_resume)
{
u32 command, temp = 0;
struct usb_hcd *hcd = xhci_to_hcd(xhci);
struct xhci_segment *seg;
int retval = 0;
bool pending_portevent = false;
bool suspended_usb3_devs = false;
bool reset_registers = false;
if (!hcd->state)
return 0;
@@ -1103,10 +1105,11 @@ int xhci_resume(struct xhci_hcd *xhci, bool power_lost, bool is_auto_resume)
spin_lock_irq(&xhci->lock);
if (xhci->quirks & XHCI_RESET_ON_RESUME || xhci->broken_suspend)
power_lost = true;
if (!power_lost) {
if (power_lost || xhci->broken_suspend || xhci->quirks & XHCI_RESET_ON_RESUME) {
xhci_dbg(xhci, "HC state lost, performing host controller reset\n");
reset_registers = true;
} else {
xhci_dbg(xhci, "HC state intact, continuing without reset\n");
/*
* Some controllers might lose power during suspend, so wait
* for controller not ready bit to clear, just as in xHC init.
@@ -1144,11 +1147,11 @@ int xhci_resume(struct xhci_hcd *xhci, bool power_lost, bool is_auto_resume)
temp = readl(&xhci->op_regs->status);
if ((temp & (STS_SRE | STS_HCE)) && !(xhci->xhc_state & XHCI_STATE_REMOVING)) {
xhci_warn(xhci, "xHC error in resume, USBSTS 0x%x, Reinit\n", temp);
power_lost = true;
reset_registers = true;
}
}
if (power_lost) {
if (reset_registers) {
if ((xhci->quirks & XHCI_COMP_MODE_QUIRK) &&
!(xhci_all_ports_seen_u0(xhci))) {
timer_delete_sync(&xhci->comp_mode_recovery_timer);
@@ -1172,27 +1175,33 @@ int xhci_resume(struct xhci_hcd *xhci, bool power_lost, bool is_auto_resume)
if (retval)
return retval;
xhci_dbg(xhci, "// Disabling event ring interrupts\n");
temp = readl(&xhci->op_regs->status);
writel((temp & ~0x1fff) | STS_EINT, &xhci->op_regs->status);
xhci_disable_interrupter(xhci, xhci->interrupters[0]);
cancel_delayed_work_sync(&xhci->cmd_timer);
/* Delete all remaining commands */
xhci_cleanup_command_queue(xhci);
/* Clear data which is re-initilized during runtime */
xhci_for_each_ring_seg(xhci->interrupters[0]->event_ring->first_seg, seg)
memset(seg->trbs, 0, sizeof(union xhci_trb) * TRBS_PER_SEGMENT);
for (int i = xhci->max_slots; i > 0; i--)
xhci_free_virt_devices_depth_first(xhci, i);
xhci_rh_bw_cleanup(xhci);
xhci->cmd_ring_reserved_trbs = 0;
xhci_for_each_ring_seg(xhci->cmd_ring->first_seg, seg)
memset(seg->trbs, 0, sizeof(union xhci_trb) * TRBS_PER_SEGMENT);
xhci_dbg(xhci, "cleaning up memory\n");
xhci_mem_cleanup(xhci);
xhci_debugfs_exit(xhci);
xhci_dbg(xhci, "xhci_stop completed - status = %x\n",
readl(&xhci->op_regs->status));
/* USB core calls the PCI reinit and start functions twice:
* first with the primary HCD, and then with the secondary HCD.
* If we don't do the same, the host will never be started.
*/
retval = xhci_mem_init(xhci, GFP_KERNEL);
if (retval)
return retval;
xhci_init(hcd);
/*
* USB core calls the PCI reinit and start functions twice:
* first with the primary HCD, and then with the secondary HCD.
* If we don't do the same, the host will never be started.
*/
xhci_dbg(xhci, "Start the primary HCD\n");
retval = xhci_run(hcd);
if (!retval && xhci->shared_hcd) {

2
drivers/usb/host/xhci.h
View File

@@ -1793,6 +1793,7 @@ void xhci_dbg_trace(struct xhci_hcd *xhci, void (*trace)(struct va_format *),
void xhci_mem_cleanup(struct xhci_hcd *xhci);
int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags);
void xhci_free_virt_device(struct xhci_hcd *xhci, struct xhci_virt_device *dev, int slot_id);
void xhci_free_virt_devices_depth_first(struct xhci_hcd *xhci, int slot_id);
int xhci_alloc_virt_device(struct xhci_hcd *xhci, int slot_id, struct usb_device *udev, gfp_t flags);
int xhci_setup_addressable_virt_dev(struct xhci_hcd *xhci, struct usb_device *udev);
void xhci_copy_ep0_dequeue_into_input_ctx(struct xhci_hcd *xhci,
@@ -1804,6 +1805,7 @@ void xhci_update_tt_active_eps(struct xhci_hcd *xhci,
struct xhci_virt_device *virt_dev,
int old_active_eps);
void xhci_clear_endpoint_bw_info(struct xhci_bw_info *bw_info);
void xhci_rh_bw_cleanup(struct xhci_hcd *xhci);
void xhci_update_bw_info(struct xhci_hcd *xhci,
struct xhci_container_ctx *in_ctx,
struct xhci_input_control_ctx *ctrl_ctx,