diff options
Diffstat (limited to 'drivers/usb/host/xhci.c')
| -rw-r--r-- | drivers/usb/host/xhci.c | 73 |
1 files changed, 63 insertions, 10 deletions
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 5d7d4e951ea4..06fca0835b52 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -577,6 +577,65 @@ static void xhci_restore_registers(struct xhci_hcd *xhci) xhci_write_64(xhci, xhci->s3.erst_base, &xhci->ir_set->erst_base); } +static void xhci_set_cmd_ring_deq(struct xhci_hcd *xhci) +{ + u64 val_64; + + /* step 2: initialize command ring buffer */ + val_64 = xhci_read_64(xhci, &xhci->op_regs->cmd_ring); + val_64 = (val_64 & (u64) CMD_RING_RSVD_BITS) | + (xhci_trb_virt_to_dma(xhci->cmd_ring->deq_seg, + xhci->cmd_ring->dequeue) & + (u64) ~CMD_RING_RSVD_BITS) | + xhci->cmd_ring->cycle_state; + xhci_dbg(xhci, "// Setting command ring address to 0x%llx\n", + (long unsigned long) val_64); + xhci_write_64(xhci, val_64, &xhci->op_regs->cmd_ring); +} + +/* + * The whole command ring must be cleared to zero when we suspend the host. + * + * The host doesn't save the command ring pointer in the suspend well, so we + * need to re-program it on resume. Unfortunately, the pointer must be 64-byte + * aligned, because of the reserved bits in the command ring dequeue pointer + * register. Therefore, we can't just set the dequeue pointer back in the + * middle of the ring (TRBs are 16-byte aligned). + */ +static void xhci_clear_command_ring(struct xhci_hcd *xhci) +{ + struct xhci_ring *ring; + struct xhci_segment *seg; + + ring = xhci->cmd_ring; + seg = ring->deq_seg; + do { + memset(seg->trbs, 0, SEGMENT_SIZE); + seg = seg->next; + } while (seg != ring->deq_seg); + + /* Reset the software enqueue and dequeue pointers */ + ring->deq_seg = ring->first_seg; + ring->dequeue = ring->first_seg->trbs; + ring->enq_seg = ring->deq_seg; + ring->enqueue = ring->dequeue; + + /* + * Ring is now zeroed, so the HW should look for change of ownership + * when the cycle bit is set to 1. + */ + ring->cycle_state = 1; + + /* + * Reset the hardware dequeue pointer. + * Yes, this will need to be re-written after resume, but we're paranoid + * and want to make sure the hardware doesn't access bogus memory + * because, say, the BIOS or an SMI started the host without changing + * the command ring pointers. + */ + xhci_set_cmd_ring_deq(xhci); +} + /* * Stop HC (not bus-specific) * @@ -604,6 +663,7 @@ int xhci_suspend(struct xhci_hcd *xhci) spin_unlock_irq(&xhci->lock); return -ETIMEDOUT; } + xhci_clear_command_ring(xhci); /* step 3: save registers */ xhci_save_registers(xhci); @@ -635,7 +695,6 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated) u32 command, temp = 0; struct usb_hcd *hcd = xhci_to_hcd(xhci); struct pci_dev *pdev = to_pci_dev(hcd->self.controller); - u64 val_64; int old_state, retval; old_state = hcd->state; @@ -648,15 +707,7 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated) /* step 1: restore register */ xhci_restore_registers(xhci); /* step 2: initialize command ring buffer */ - val_64 = xhci_read_64(xhci, &xhci->op_regs->cmd_ring); - val_64 = (val_64 & (u64) CMD_RING_RSVD_BITS) | - (xhci_trb_virt_to_dma(xhci->cmd_ring->deq_seg, - xhci->cmd_ring->dequeue) & - (u64) ~CMD_RING_RSVD_BITS) | - xhci->cmd_ring->cycle_state; - xhci_dbg(xhci, "// Setting command ring address to 0x%llx\n", - (long unsigned long) val_64); - xhci_write_64(xhci, val_64, &xhci->op_regs->cmd_ring); + xhci_set_cmd_ring_deq(xhci); /* step 3: restore state and start state*/ /* step 3: set CRS flag */ command = xhci_readl(xhci, &xhci->op_regs->command); @@ -714,6 +765,7 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated) return retval; } + spin_unlock_irq(&xhci->lock); /* Re-setup MSI-X */ if (hcd->irq) free_irq(hcd->irq, hcd); @@ -736,6 +788,7 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated) hcd->irq = pdev->irq; } + spin_lock_irq(&xhci->lock); /* step 4: set Run/Stop bit */ command = xhci_readl(xhci, &xhci->op_regs->command); command |= CMD_RUN; |