From: Matthew Wilcox <matthew@xxxxxx> The unused space in the doorbell is now marked as RsvdZ, not RsvdP, so we can avoid reading the doorbell before writing it. Update the doorbell-related defines to produce the entire doorbell value from a single macro. Document the doorbell format in a comment. Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxxxx> Signed-off-by: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx> --- drivers/usb/host/xhci-ring.c | 27 +++++++++++---------------- drivers/usb/host/xhci.h | 16 ++++++---------- 2 files changed, 17 insertions(+), 26 deletions(-) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 2116c0f..3e8211c 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -308,11 +308,8 @@ static int room_on_ring(struct xhci_hcd *xhci, struct xhci_ring *ring, /* Ring the host controller doorbell after placing a command on the ring */ void xhci_ring_cmd_db(struct xhci_hcd *xhci) { - u32 temp; - xhci_dbg(xhci, "// Ding dong!\n"); - temp = xhci_readl(xhci, &xhci->dba->doorbell[0]) & DB_MASK; - xhci_writel(xhci, temp | DB_TARGET_HOST, &xhci->dba->doorbell[0]); + xhci_writel(xhci, DB_VALUE_HOST, &xhci->dba->doorbell[0]); /* Flush PCI posted writes */ xhci_readl(xhci, &xhci->dba->doorbell[0]); } @@ -322,26 +319,24 @@ void xhci_ring_ep_doorbell(struct xhci_hcd *xhci, unsigned int ep_index, unsigned int stream_id) { - struct xhci_virt_ep *ep; - unsigned int ep_state; - u32 field; __u32 __iomem *db_addr = &xhci->dba->doorbell[slot_id]; + struct xhci_virt_ep *ep = &xhci->devs[slot_id]->eps[ep_index]; + unsigned int ep_state = ep->ep_state; - ep = &xhci->devs[slot_id]->eps[ep_index]; - ep_state = ep->ep_state; /* Don't ring the doorbell for this endpoint if there are pending - * cancellations because the we don't want to interrupt processing. + * cancellations because we don't want to interrupt processing. * We don't want to restart any stream rings if there's a set dequeue * pointer command pending because the device can choose to start any * stream once the endpoint is on the HW schedule. * FIXME - check all the stream rings for pending cancellations. */ - if (!(ep_state & EP_HALT_PENDING) && !(ep_state & SET_DEQ_PENDING) - && !(ep_state & EP_HALTED)) { - field = xhci_readl(xhci, db_addr) & DB_MASK; - field |= EPI_TO_DB(ep_index) | STREAM_ID_TO_DB(stream_id); - xhci_writel(xhci, field, db_addr); - } + if ((ep_state & EP_HALT_PENDING) || (ep_state & SET_DEQ_PENDING) || + (ep_state & EP_HALTED)) + return; + xhci_writel(xhci, DB_VALUE(ep_index, stream_id), db_addr); + /* The CPU has better things to do at this point than wait for a + * write-posting flush. It'll get there soon enough. + */ } /* Ring the doorbell for any rings with pending URBs */ diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index 170c367..7f236fd 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -436,22 +436,18 @@ struct xhci_run_regs { /** * struct doorbell_array * + * Bits 0 - 7: Endpoint target + * Bits 8 - 15: RsvdZ + * Bits 16 - 31: Stream ID + * * Section 5.6 */ struct xhci_doorbell_array { u32 doorbell[256]; }; -#define DB_TARGET_MASK 0xFFFFFF00 -#define DB_STREAM_ID_MASK 0x0000FFFF -#define DB_TARGET_HOST 0x0 -#define DB_STREAM_ID_HOST 0x0 -#define DB_MASK (0xff << 8) - -/* Endpoint Target - bits 0:7 */ -#define EPI_TO_DB(p) (((p) + 1) & 0xff) -#define STREAM_ID_TO_DB(p) (((p) & 0xffff) << 16) - +#define DB_VALUE(ep, stream) ((((ep) + 1) & 0xff) | ((stream) << 16)) +#define DB_VALUE_HOST 0x00000000 /** * struct xhci_protocol_caps -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html