Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

[linux/fpc-iii.git] / drivers / usb / host / xhci-dbg.c

/*
 * xHCI host controller driver
 *
 * Copyright (C) 2008 Intel Corp.
 *
 * Author: Sarah Sharp
 * Some code borrowed from the Linux EHCI driver.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include "xhci.h"

#define XHCI_INIT_VALUE 0x0

/* Add verbose debugging later, just print everything for now */

void xhci_dbg_regs(struct xhci_hcd *xhci)
{
        u32 temp;

        xhci_dbg(xhci, "// xHCI capability registers at %p:\n",
                        xhci->cap_regs);
        temp = readl(&xhci->cap_regs->hc_capbase);
        xhci_dbg(xhci, "// @%p = 0x%x (CAPLENGTH AND HCIVERSION)\n",
                        &xhci->cap_regs->hc_capbase, temp);
        xhci_dbg(xhci, "//   CAPLENGTH: 0x%x\n",
                        (unsigned int) HC_LENGTH(temp));
#if 0
        xhci_dbg(xhci, "//   HCIVERSION: 0x%x\n",
                        (unsigned int) HC_VERSION(temp));
#endif

        xhci_dbg(xhci, "// xHCI operational registers at %p:\n", xhci->op_regs);

        temp = readl(&xhci->cap_regs->run_regs_off);
        xhci_dbg(xhci, "// @%p = 0x%x RTSOFF\n",
                        &xhci->cap_regs->run_regs_off,
                        (unsigned int) temp & RTSOFF_MASK);
        xhci_dbg(xhci, "// xHCI runtime registers at %p:\n", xhci->run_regs);

        temp = readl(&xhci->cap_regs->db_off);
        xhci_dbg(xhci, "// @%p = 0x%x DBOFF\n", &xhci->cap_regs->db_off, temp);
        xhci_dbg(xhci, "// Doorbell array at %p:\n", xhci->dba);
}

static void xhci_print_cap_regs(struct xhci_hcd *xhci)
{
        u32 temp;

        xhci_dbg(xhci, "xHCI capability registers at %p:\n", xhci->cap_regs);

        temp = readl(&xhci->cap_regs->hc_capbase);
        xhci_dbg(xhci, "CAPLENGTH AND HCIVERSION 0x%x:\n",
                        (unsigned int) temp);
        xhci_dbg(xhci, "CAPLENGTH: 0x%x\n",
                        (unsigned int) HC_LENGTH(temp));
        xhci_dbg(xhci, "HCIVERSION: 0x%x\n",
                        (unsigned int) HC_VERSION(temp));

        temp = readl(&xhci->cap_regs->hcs_params1);
        xhci_dbg(xhci, "HCSPARAMS 1: 0x%x\n",
                        (unsigned int) temp);
        xhci_dbg(xhci, "  Max device slots: %u\n",
                        (unsigned int) HCS_MAX_SLOTS(temp));
        xhci_dbg(xhci, "  Max interrupters: %u\n",
                        (unsigned int) HCS_MAX_INTRS(temp));
        xhci_dbg(xhci, "  Max ports: %u\n",
                        (unsigned int) HCS_MAX_PORTS(temp));

        temp = readl(&xhci->cap_regs->hcs_params2);
        xhci_dbg(xhci, "HCSPARAMS 2: 0x%x\n",
                        (unsigned int) temp);
        xhci_dbg(xhci, "  Isoc scheduling threshold: %u\n",
                        (unsigned int) HCS_IST(temp));
        xhci_dbg(xhci, "  Maximum allowed segments in event ring: %u\n",
                        (unsigned int) HCS_ERST_MAX(temp));

        temp = readl(&xhci->cap_regs->hcs_params3);
        xhci_dbg(xhci, "HCSPARAMS 3 0x%x:\n",
                        (unsigned int) temp);
        xhci_dbg(xhci, "  Worst case U1 device exit latency: %u\n",
                        (unsigned int) HCS_U1_LATENCY(temp));
        xhci_dbg(xhci, "  Worst case U2 device exit latency: %u\n",
                        (unsigned int) HCS_U2_LATENCY(temp));

        temp = readl(&xhci->cap_regs->hcc_params);
        xhci_dbg(xhci, "HCC PARAMS 0x%x:\n", (unsigned int) temp);
        xhci_dbg(xhci, "  HC generates %s bit addresses\n",
                        HCC_64BIT_ADDR(temp) ? "64" : "32");
        /* FIXME */
        xhci_dbg(xhci, "  FIXME: more HCCPARAMS debugging\n");

        temp = readl(&xhci->cap_regs->run_regs_off);
        xhci_dbg(xhci, "RTSOFF 0x%x:\n", temp & RTSOFF_MASK);
}

static void xhci_print_command_reg(struct xhci_hcd *xhci)
{
        u32 temp;

        temp = readl(&xhci->op_regs->command);
        xhci_dbg(xhci, "USBCMD 0x%x:\n", temp);
        xhci_dbg(xhci, "  HC is %s\n",
                        (temp & CMD_RUN) ? "running" : "being stopped");
        xhci_dbg(xhci, "  HC has %sfinished hard reset\n",
                        (temp & CMD_RESET) ? "not " : "");
        xhci_dbg(xhci, "  Event Interrupts %s\n",
                        (temp & CMD_EIE) ? "enabled " : "disabled");
        xhci_dbg(xhci, "  Host System Error Interrupts %s\n",
                        (temp & CMD_HSEIE) ? "enabled " : "disabled");
        xhci_dbg(xhci, "  HC has %sfinished light reset\n",
                        (temp & CMD_LRESET) ? "not " : "");
}

static void xhci_print_status(struct xhci_hcd *xhci)
{
        u32 temp;

        temp = readl(&xhci->op_regs->status);
        xhci_dbg(xhci, "USBSTS 0x%x:\n", temp);
        xhci_dbg(xhci, "  Event ring is %sempty\n",
                        (temp & STS_EINT) ? "not " : "");
        xhci_dbg(xhci, "  %sHost System Error\n",
                        (temp & STS_FATAL) ? "WARNING: " : "No ");
        xhci_dbg(xhci, "  HC is %s\n",
                        (temp & STS_HALT) ? "halted" : "running");
}

static void xhci_print_op_regs(struct xhci_hcd *xhci)
{
        xhci_dbg(xhci, "xHCI operational registers at %p:\n", xhci->op_regs);
        xhci_print_command_reg(xhci);
        xhci_print_status(xhci);
}

static void xhci_print_ports(struct xhci_hcd *xhci)
{
        __le32 __iomem *addr;
        int i, j;
        int ports;
        char *names[NUM_PORT_REGS] = {
                "status",
                "power",
                "link",
                "reserved",
        };

        ports = HCS_MAX_PORTS(xhci->hcs_params1);
        addr = &xhci->op_regs->port_status_base;
        for (i = 0; i < ports; i++) {
                for (j = 0; j < NUM_PORT_REGS; ++j) {
                        xhci_dbg(xhci, "%p port %s reg = 0x%x\n",
                                        addr, names[j],
                                        (unsigned int) readl(addr));
                        addr++;
                }
        }
}

void xhci_print_ir_set(struct xhci_hcd *xhci, int set_num)
{
        struct xhci_intr_reg __iomem *ir_set = &xhci->run_regs->ir_set[set_num];
        void __iomem *addr;
        u32 temp;
        u64 temp_64;

        addr = &ir_set->irq_pending;
        temp = readl(addr);
        if (temp == XHCI_INIT_VALUE)
                return;

        xhci_dbg(xhci, "  %p: ir_set[%i]\n", ir_set, set_num);

        xhci_dbg(xhci, "  %p: ir_set.pending = 0x%x\n", addr,
                        (unsigned int)temp);

        addr = &ir_set->irq_control;
        temp = readl(addr);
        xhci_dbg(xhci, "  %p: ir_set.control = 0x%x\n", addr,
                        (unsigned int)temp);

        addr = &ir_set->erst_size;
        temp = readl(addr);
        xhci_dbg(xhci, "  %p: ir_set.erst_size = 0x%x\n", addr,
                        (unsigned int)temp);

        addr = &ir_set->rsvd;
        temp = readl(addr);
        if (temp != XHCI_INIT_VALUE)
                xhci_dbg(xhci, "  WARN: %p: ir_set.rsvd = 0x%x\n",
                                addr, (unsigned int)temp);

        addr = &ir_set->erst_base;
        temp_64 = readq(addr);
        xhci_dbg(xhci, "  %p: ir_set.erst_base = @%08llx\n",
                        addr, temp_64);

        addr = &ir_set->erst_dequeue;
        temp_64 = readq(addr);
        xhci_dbg(xhci, "  %p: ir_set.erst_dequeue = @%08llx\n",
                        addr, temp_64);
}

void xhci_print_run_regs(struct xhci_hcd *xhci)
{
        u32 temp;
        int i;

        xhci_dbg(xhci, "xHCI runtime registers at %p:\n", xhci->run_regs);
        temp = readl(&xhci->run_regs->microframe_index);
        xhci_dbg(xhci, "  %p: Microframe index = 0x%x\n",
                        &xhci->run_regs->microframe_index,
                        (unsigned int) temp);
        for (i = 0; i < 7; ++i) {
                temp = readl(&xhci->run_regs->rsvd[i]);
                if (temp != XHCI_INIT_VALUE)
                        xhci_dbg(xhci, "  WARN: %p: Rsvd[%i] = 0x%x\n",
                                        &xhci->run_regs->rsvd[i],
                                        i, (unsigned int) temp);
        }
}

void xhci_print_registers(struct xhci_hcd *xhci)
{
        xhci_print_cap_regs(xhci);
        xhci_print_op_regs(xhci);
        xhci_print_ports(xhci);
}

void xhci_print_trb_offsets(struct xhci_hcd *xhci, union xhci_trb *trb)
{
        int i;
        for (i = 0; i < 4; ++i)
                xhci_dbg(xhci, "Offset 0x%x = 0x%x\n",
                                i*4, trb->generic.field[i]);
}

/**
 * Debug a transfer request block (TRB).
 */
void xhci_debug_trb(struct xhci_hcd *xhci, union xhci_trb *trb)
{
        u64     address;
        u32     type = le32_to_cpu(trb->link.control) & TRB_TYPE_BITMASK;

        switch (type) {
        case TRB_TYPE(TRB_LINK):
                xhci_dbg(xhci, "Link TRB:\n");
                xhci_print_trb_offsets(xhci, trb);

                address = le64_to_cpu(trb->link.segment_ptr);
                xhci_dbg(xhci, "Next ring segment DMA address = 0x%llx\n", address);

                xhci_dbg(xhci, "Interrupter target = 0x%x\n",
                         GET_INTR_TARGET(le32_to_cpu(trb->link.intr_target)));
                xhci_dbg(xhci, "Cycle bit = %u\n",
                         le32_to_cpu(trb->link.control) & TRB_CYCLE);
                xhci_dbg(xhci, "Toggle cycle bit = %u\n",
                         le32_to_cpu(trb->link.control) & LINK_TOGGLE);
                xhci_dbg(xhci, "No Snoop bit = %u\n",
                         le32_to_cpu(trb->link.control) & TRB_NO_SNOOP);
                break;
        case TRB_TYPE(TRB_TRANSFER):
                address = le64_to_cpu(trb->trans_event.buffer);
                /*
                 * FIXME: look at flags to figure out if it's an address or if
                 * the data is directly in the buffer field.
                 */
                xhci_dbg(xhci, "DMA address or buffer contents= %llu\n", address);
                break;
        case TRB_TYPE(TRB_COMPLETION):
                address = le64_to_cpu(trb->event_cmd.cmd_trb);
                xhci_dbg(xhci, "Command TRB pointer = %llu\n", address);
                xhci_dbg(xhci, "Completion status = %u\n",
                         GET_COMP_CODE(le32_to_cpu(trb->event_cmd.status)));
                xhci_dbg(xhci, "Flags = 0x%x\n",
                         le32_to_cpu(trb->event_cmd.flags));
                break;
        default:
                xhci_dbg(xhci, "Unknown TRB with TRB type ID %u\n",
                                (unsigned int) type>>10);
                xhci_print_trb_offsets(xhci, trb);
                break;
        }
}

/**
 * Debug a segment with an xHCI ring.
 *
 * @return The Link TRB of the segment, or NULL if there is no Link TRB
 * (which is a bug, since all segments must have a Link TRB).
 *
 * Prints out all TRBs in the segment, even those after the Link TRB.
 *
 * XXX: should we print out TRBs that the HC owns?  As long as we don't
 * write, that should be fine...  We shouldn't expect that the memory pointed to
 * by the TRB is valid at all.  Do we care about ones the HC owns?  Probably,
 * for HC debugging.
 */
void xhci_debug_segment(struct xhci_hcd *xhci, struct xhci_segment *seg)
{
        int i;
        u64 addr = seg->dma;
        union xhci_trb *trb = seg->trbs;

        for (i = 0; i < TRBS_PER_SEGMENT; ++i) {
                trb = &seg->trbs[i];
                xhci_dbg(xhci, "@%016llx %08x %08x %08x %08x\n", addr,
                         lower_32_bits(le64_to_cpu(trb->link.segment_ptr)),
                         upper_32_bits(le64_to_cpu(trb->link.segment_ptr)),
                         le32_to_cpu(trb->link.intr_target),
                         le32_to_cpu(trb->link.control));
                addr += sizeof(*trb);
        }
}

void xhci_dbg_ring_ptrs(struct xhci_hcd *xhci, struct xhci_ring *ring)
{
        xhci_dbg(xhci, "Ring deq = %p (virt), 0x%llx (dma)\n",
                        ring->dequeue,
                        (unsigned long long)xhci_trb_virt_to_dma(ring->deq_seg,
                                                            ring->dequeue));
        xhci_dbg(xhci, "Ring deq updated %u times\n",
                        ring->deq_updates);
        xhci_dbg(xhci, "Ring enq = %p (virt), 0x%llx (dma)\n",
                        ring->enqueue,
                        (unsigned long long)xhci_trb_virt_to_dma(ring->enq_seg,
                                                            ring->enqueue));
        xhci_dbg(xhci, "Ring enq updated %u times\n",
                        ring->enq_updates);
}

/**
 * Debugging for an xHCI ring, which is a queue broken into multiple segments.
 *
 * Print out each segment in the ring.  Check that the DMA address in
 * each link segment actually matches the segment's stored DMA address.
 * Check that the link end bit is only set at the end of the ring.
 * Check that the dequeue and enqueue pointers point to real data in this ring
 * (not some other ring).
 */
void xhci_debug_ring(struct xhci_hcd *xhci, struct xhci_ring *ring)
{
        /* FIXME: Throw an error if any segment doesn't have a Link TRB */
        struct xhci_segment *seg;
        struct xhci_segment *first_seg = ring->first_seg;
        xhci_debug_segment(xhci, first_seg);

        if (!ring->enq_updates && !ring->deq_updates) {
                xhci_dbg(xhci, "  Ring has not been updated\n");
                return;
        }
        for (seg = first_seg->next; seg != first_seg; seg = seg->next)
                xhci_debug_segment(xhci, seg);
}

void xhci_dbg_ep_rings(struct xhci_hcd *xhci,
                unsigned int slot_id, unsigned int ep_index,
                struct xhci_virt_ep *ep)
{
        int i;
        struct xhci_ring *ring;

        if (ep->ep_state & EP_HAS_STREAMS) {
                for (i = 1; i < ep->stream_info->num_streams; i++) {
                        ring = ep->stream_info->stream_rings[i];
                        xhci_dbg(xhci, "Dev %d endpoint %d stream ID %d:\n",
                                slot_id, ep_index, i);
                        xhci_debug_segment(xhci, ring->deq_seg);
                }
        } else {
                ring = ep->ring;
                if (!ring)
                        return;
                xhci_dbg(xhci, "Dev %d endpoint ring %d:\n",
                                slot_id, ep_index);
                xhci_debug_segment(xhci, ring->deq_seg);
        }
}

void xhci_dbg_erst(struct xhci_hcd *xhci, struct xhci_erst *erst)
{
        u64 addr = erst->erst_dma_addr;
        int i;
        struct xhci_erst_entry *entry;

        for (i = 0; i < erst->num_entries; ++i) {
                entry = &erst->entries[i];
                xhci_dbg(xhci, "@%016llx %08x %08x %08x %08x\n",
                         addr,
                         lower_32_bits(le64_to_cpu(entry->seg_addr)),
                         upper_32_bits(le64_to_cpu(entry->seg_addr)),
                         le32_to_cpu(entry->seg_size),
                         le32_to_cpu(entry->rsvd));
                addr += sizeof(*entry);
        }
}

void xhci_dbg_cmd_ptrs(struct xhci_hcd *xhci)
{
        u64 val;

        val = readq(&xhci->op_regs->cmd_ring);
        xhci_dbg(xhci, "// xHC command ring deq ptr low bits + flags = @%08x\n",
                        lower_32_bits(val));
        xhci_dbg(xhci, "// xHC command ring deq ptr high bits = @%08x\n",
                        upper_32_bits(val));
}

/* Print the last 32 bytes for 64-byte contexts */
static void dbg_rsvd64(struct xhci_hcd *xhci, u64 *ctx, dma_addr_t dma)
{
        int i;
        for (i = 0; i < 4; ++i) {
                xhci_dbg(xhci, "@%p (virt) @%08llx "
                         "(dma) %#08llx - rsvd64[%d]\n",
                         &ctx[4 + i], (unsigned long long)dma,
                         ctx[4 + i], i);
                dma += 8;
        }
}

char *xhci_get_slot_state(struct xhci_hcd *xhci,
                struct xhci_container_ctx *ctx)
{
        struct xhci_slot_ctx *slot_ctx = xhci_get_slot_ctx(xhci, ctx);

        switch (GET_SLOT_STATE(le32_to_cpu(slot_ctx->dev_state))) {
        case SLOT_STATE_ENABLED:
                return "enabled/disabled";
        case SLOT_STATE_DEFAULT:
                return "default";
        case SLOT_STATE_ADDRESSED:
                return "addressed";
        case SLOT_STATE_CONFIGURED:
                return "configured";
        default:
                return "reserved";
        }
}

static void xhci_dbg_slot_ctx(struct xhci_hcd *xhci, struct xhci_container_ctx *ctx)
{
        /* Fields are 32 bits wide, DMA addresses are in bytes */
        int field_size = 32 / 8;
        int i;

        struct xhci_slot_ctx *slot_ctx = xhci_get_slot_ctx(xhci, ctx);
        dma_addr_t dma = ctx->dma +
                ((unsigned long)slot_ctx - (unsigned long)ctx->bytes);
        int csz = HCC_64BYTE_CONTEXT(xhci->hcc_params);

        xhci_dbg(xhci, "Slot Context:\n");
        xhci_dbg(xhci, "@%p (virt) @%08llx (dma) %#08x - dev_info\n",
                        &slot_ctx->dev_info,
                        (unsigned long long)dma, slot_ctx->dev_info);
        dma += field_size;
        xhci_dbg(xhci, "@%p (virt) @%08llx (dma) %#08x - dev_info2\n",
                        &slot_ctx->dev_info2,
                        (unsigned long long)dma, slot_ctx->dev_info2);
        dma += field_size;
        xhci_dbg(xhci, "@%p (virt) @%08llx (dma) %#08x - tt_info\n",
                        &slot_ctx->tt_info,
                        (unsigned long long)dma, slot_ctx->tt_info);
        dma += field_size;
        xhci_dbg(xhci, "@%p (virt) @%08llx (dma) %#08x - dev_state\n",
                        &slot_ctx->dev_state,
                        (unsigned long long)dma, slot_ctx->dev_state);
        dma += field_size;
        for (i = 0; i < 4; ++i) {
                xhci_dbg(xhci, "@%p (virt) @%08llx (dma) %#08x - rsvd[%d]\n",
                                &slot_ctx->reserved[i], (unsigned long long)dma,
                                slot_ctx->reserved[i], i);
                dma += field_size;
        }

        if (csz)
                dbg_rsvd64(xhci, (u64 *)slot_ctx, dma);
}

static void xhci_dbg_ep_ctx(struct xhci_hcd *xhci,
                     struct xhci_container_ctx *ctx,
                     unsigned int last_ep)
{
        int i, j;
        int last_ep_ctx = 31;
        /* Fields are 32 bits wide, DMA addresses are in bytes */
        int field_size = 32 / 8;
        int csz = HCC_64BYTE_CONTEXT(xhci->hcc_params);

        if (last_ep < 31)
                last_ep_ctx = last_ep + 1;
        for (i = 0; i < last_ep_ctx; ++i) {
                unsigned int epaddr = xhci_get_endpoint_address(i);
                struct xhci_ep_ctx *ep_ctx = xhci_get_ep_ctx(xhci, ctx, i);
                dma_addr_t dma = ctx->dma +
                        ((unsigned long)ep_ctx - (unsigned long)ctx->bytes);

                xhci_dbg(xhci, "%s Endpoint %02d Context (ep_index %02d):\n",
                                usb_endpoint_out(epaddr) ? "OUT" : "IN",
                                epaddr & USB_ENDPOINT_NUMBER_MASK, i);
                xhci_dbg(xhci, "@%p (virt) @%08llx (dma) %#08x - ep_info\n",
                                &ep_ctx->ep_info,
                                (unsigned long long)dma, ep_ctx->ep_info);
                dma += field_size;
                xhci_dbg(xhci, "@%p (virt) @%08llx (dma) %#08x - ep_info2\n",
                                &ep_ctx->ep_info2,
                                (unsigned long long)dma, ep_ctx->ep_info2);
                dma += field_size;
                xhci_dbg(xhci, "@%p (virt) @%08llx (dma) %#08llx - deq\n",
                                &ep_ctx->deq,
                                (unsigned long long)dma, ep_ctx->deq);
                dma += 2*field_size;
                xhci_dbg(xhci, "@%p (virt) @%08llx (dma) %#08x - tx_info\n",
                                &ep_ctx->tx_info,
                                (unsigned long long)dma, ep_ctx->tx_info);
                dma += field_size;
                for (j = 0; j < 3; ++j) {
                        xhci_dbg(xhci, "@%p (virt) @%08llx (dma) %#08x - rsvd[%d]\n",
                                        &ep_ctx->reserved[j],
                                        (unsigned long long)dma,
                                        ep_ctx->reserved[j], j);
                        dma += field_size;
                }

                if (csz)
                        dbg_rsvd64(xhci, (u64 *)ep_ctx, dma);
        }
}

void xhci_dbg_ctx(struct xhci_hcd *xhci,
                  struct xhci_container_ctx *ctx,
                  unsigned int last_ep)
{
        int i;
        /* Fields are 32 bits wide, DMA addresses are in bytes */
        int field_size = 32 / 8;
        dma_addr_t dma = ctx->dma;
        int csz = HCC_64BYTE_CONTEXT(xhci->hcc_params);

        if (ctx->type == XHCI_CTX_TYPE_INPUT) {
                struct xhci_input_control_ctx *ctrl_ctx =
                        xhci_get_input_control_ctx(xhci, ctx);
                if (!ctrl_ctx) {
                        xhci_warn(xhci, "Could not get input context, bad type.\n");
                        return;
                }

                xhci_dbg(xhci, "@%p (virt) @%08llx (dma) %#08x - drop flags\n",
                         &ctrl_ctx->drop_flags, (unsigned long long)dma,
                         ctrl_ctx->drop_flags);
                dma += field_size;
                xhci_dbg(xhci, "@%p (virt) @%08llx (dma) %#08x - add flags\n",
                         &ctrl_ctx->add_flags, (unsigned long long)dma,
                         ctrl_ctx->add_flags);
                dma += field_size;
                for (i = 0; i < 6; ++i) {
                        xhci_dbg(xhci, "@%p (virt) @%08llx (dma) %#08x - rsvd2[%d]\n",
                                 &ctrl_ctx->rsvd2[i], (unsigned long long)dma,
                                 ctrl_ctx->rsvd2[i], i);
                        dma += field_size;
                }

                if (csz)
                        dbg_rsvd64(xhci, (u64 *)ctrl_ctx, dma);
        }

        xhci_dbg_slot_ctx(xhci, ctx);
        xhci_dbg_ep_ctx(xhci, ctx, last_ep);
}

void xhci_dbg_trace(struct xhci_hcd *xhci, void (*trace)(struct va_format *),
                        const char *fmt, ...)
{
        struct va_format vaf;
        va_list args;

        va_start(args, fmt);
        vaf.fmt = fmt;
        vaf.va = &args;
        xhci_dbg(xhci, "%pV\n", &vaf);
        trace(&vaf);
        va_end(args);
}