diff options
Diffstat (limited to 'drivers/usb/host')
| -rw-r--r-- | drivers/usb/host/xhci-hcd.c | 12 | ||||
| -rw-r--r-- | drivers/usb/host/xhci-mem.c | 3 | ||||
| -rw-r--r-- | drivers/usb/host/xhci-ring.c | 15 | ||||
| -rw-r--r-- | drivers/usb/host/xhci.h | 9 |
4 files changed, 35 insertions, 4 deletions
diff --git a/drivers/usb/host/xhci-hcd.c b/drivers/usb/host/xhci-hcd.c index 816c39caca1..994f4c0dda2 100644 --- a/drivers/usb/host/xhci-hcd.c +++ b/drivers/usb/host/xhci-hcd.c @@ -22,12 +22,18 @@ #include <linux/irq.h> #include <linux/module.h> +#include <linux/moduleparam.h> #include "xhci.h" #define DRIVER_AUTHOR "Sarah Sharp" #define DRIVER_DESC "'eXtensible' Host Controller (xHC) Driver" +/* Some 0.95 hardware can't handle the chain bit on a Link TRB being cleared */ +static int link_quirk; +module_param(link_quirk, int, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(link_quirk, "Don't clear the chain bit on a link TRB"); + /* TODO: copied from ehci-hcd.c - can this be refactored? */ /* * handshake - spin reading hc until handshake completes or fails @@ -214,6 +220,12 @@ int xhci_init(struct usb_hcd *hcd) xhci_dbg(xhci, "xhci_init\n"); spin_lock_init(&xhci->lock); + if (link_quirk) { + xhci_dbg(xhci, "QUIRK: Not clearing Link TRB chain bits.\n"); + xhci->quirks |= XHCI_LINK_TRB_QUIRK; + } else { + xhci_dbg(xhci, "xHCI has no QUIRKS\n"); + } retval = xhci_mem_init(xhci, GFP_KERNEL); xhci_dbg(xhci, "Finished xhci_init\n"); diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c index e6b9a1c6002..cb2033879ae 100644 --- a/drivers/usb/host/xhci-mem.c +++ b/drivers/usb/host/xhci-mem.c @@ -94,6 +94,9 @@ static void xhci_link_segments(struct xhci_hcd *xhci, struct xhci_segment *prev, val = prev->trbs[TRBS_PER_SEGMENT-1].link.control; val &= ~TRB_TYPE_BITMASK; val |= TRB_TYPE(TRB_LINK); + /* Always set the chain bit with 0.95 hardware */ + if (xhci_link_trb_quirk(xhci)) + val |= TRB_CHAIN; prev->trbs[TRBS_PER_SEGMENT-1].link.control = val; } xhci_dbg(xhci, "Linking segment 0x%llx to segment 0x%llx (DMA)\n", diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index aa88a067148..011458f4d9c 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -172,8 +172,9 @@ static void inc_deq(struct xhci_hcd *xhci, struct xhci_ring *ring, bool consumer * have their chain bit cleared (so that each Link TRB is a separate TD). * * Section 6.4.4.1 of the 0.95 spec says link TRBs cannot have the chain bit - * set, but other sections talk about dealing with the chain bit set. - * Assume section 6.4.4.1 is wrong, and the chain bit can be set in a Link TRB. + * set, but other sections talk about dealing with the chain bit set. This was + * fixed in the 0.96 specification errata, but we have to assume that all 0.95 + * xHCI hardware can't handle the chain bit being cleared on a link TRB. */ static void inc_enq(struct xhci_hcd *xhci, struct xhci_ring *ring, bool consumer) { @@ -191,8 +192,14 @@ static void inc_enq(struct xhci_hcd *xhci, struct xhci_ring *ring, bool consumer while (last_trb(xhci, ring, ring->enq_seg, next)) { if (!consumer) { if (ring != xhci->event_ring) { - next->link.control &= ~TRB_CHAIN; - next->link.control |= chain; + /* If we're not dealing with 0.95 hardware, + * carry over the chain bit of the previous TRB + * (which may mean the chain bit is cleared). + */ + if (!xhci_link_trb_quirk(xhci)) { + next->link.control &= ~TRB_CHAIN; + next->link.control |= chain; + } /* Give this link TRB to the hardware */ wmb(); if (next->link.control & TRB_CYCLE) diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index ffe1625d4e1..79ea627e8b8 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -1058,6 +1058,8 @@ struct xhci_hcd { int noops_submitted; int noops_handled; int error_bitmask; + unsigned int quirks; +#define XHCI_LINK_TRB_QUIRK (1 << 0) }; /* For testing purposes */ @@ -1136,6 +1138,13 @@ static inline void xhci_write_64(struct xhci_hcd *xhci, writel(val_hi, ptr + 1); } +static inline int xhci_link_trb_quirk(struct xhci_hcd *xhci) +{ + u32 temp = xhci_readl(xhci, &xhci->cap_regs->hc_capbase); + return ((HC_VERSION(temp) == 0x95) && + (xhci->quirks & XHCI_LINK_TRB_QUIRK)); +} + /* xHCI debugging */ void xhci_print_ir_set(struct xhci_hcd *xhci, struct xhci_intr_reg *ir_set, int set_num); void xhci_print_registers(struct xhci_hcd *xhci); |