From: Andiry Xu Date: Thu, 5 May 2011 10:14:02 +0000 (+0800) Subject: xHCI 1.0: Block Interrupts for Isoch transfer X-Git-Url: http://git.mmlx.us/?a=commitdiff_plain;h=ad106f292369d753d5c75751cb9e760726e3cd00;p=linux-edison.git xHCI 1.0: Block Interrupts for Isoch transfer Currently an isoc URB is divided into multiple TDs, and every TD will trigger an interrupt when it's processed. However, software can schedule multiple TDs at a time, and it only needs an interrupt every URB. xHCI 1.0 introduces the Block Event Interrupt(BEI) flag which allows Normal and Isoch Transfer TRBs to place an Event TRB on an Event Ring but not assert an intrrupt to the host, and the interrupt rate is significantly reduced and the system performance is improved. Signed-off-by: Andiry Xu Signed-off-by: Sarah Sharp --- diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 3e759af049b..c35058b94de 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -3293,6 +3293,11 @@ static int xhci_queue_isoc_tx(struct xhci_hcd *xhci, gfp_t mem_flags, } else { td->last_trb = ep_ring->enqueue; field |= TRB_IOC; + if (xhci->hci_version == 0x100) { + /* Set BEI bit except for the last td */ + if (i < num_tds - 1) + field |= TRB_BEI; + } more_trbs_coming = false; } diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index af8b66f2fd0..33a49d5d6c2 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -964,6 +964,8 @@ struct xhci_event_cmd { /* The buffer pointer contains immediate data */ #define TRB_IDT (1<<6) +/* Block Event Interrupt */ +#define TRB_BEI (1<<9) /* Control transfer TRB specific fields */ #define TRB_DIR_IN (1<<16)