redonkable/alistair23-linux
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IB/qib: Avoid duplicate writes to the rcv head register

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Avoid duplicate writes to the head register as this can lead to lost
interrupts if the context goes full before the second write is done.

Signed-off-by: Mike Marciniszyn <mike.marciniszyn@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
This commit is contained in:
Mike Marciniszyn 2011-01-10 17:42:21 -08:00 committed by Roland Dreier
parent e706203c7c
commit aa7374ac19
1 changed files with 9 additions and 1 deletions
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10
drivers/infiniband/hw/qib/qib_driver.c
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@ -71,6 +71,11 @@ MODULE_DESCRIPTION("QLogic IB driver");
*/ */
#define QIB_PIO_MAXIBHDR 128 #define QIB_PIO_MAXIBHDR 128
/*
* QIB_MAX_PKT_RCV is the max # if packets processed per receive interrupt.
*/
#define QIB_MAX_PKT_RECV 64
struct qlogic_ib_stats qib_stats; struct qlogic_ib_stats qib_stats;
const char *qib_get_unit_name(int unit) const char *qib_get_unit_name(int unit)
@ -335,7 +340,7 @@ u32 qib_kreceive(struct qib_ctxtdata *rcd, u32 *llic, u32 *npkts)
smp_rmb(); /* prevent speculative reads of dma'ed hdrq */ smp_rmb(); /* prevent speculative reads of dma'ed hdrq */
} }
for (last = 0, i = 1; !last && i <= 64; i += !last) { for (last = 0, i = 1; !last; i += !last) {
hdr = dd->f_get_msgheader(dd, rhf_addr); hdr = dd->f_get_msgheader(dd, rhf_addr);
eflags = qib_hdrget_err_flags(rhf_addr); eflags = qib_hdrget_err_flags(rhf_addr);
etype = qib_hdrget_rcv_type(rhf_addr); etype = qib_hdrget_rcv_type(rhf_addr);
@ -384,6 +389,9 @@ move_along:
l += rsize; l += rsize;
if (l >= maxcnt) if (l >= maxcnt)
l = 0; l = 0;
if (i == QIB_MAX_PKT_RECV)
last = 1;
rhf_addr = (__le32 *) rcd->rcvhdrq + l + dd->rhf_offset; rhf_addr = (__le32 *) rcd->rcvhdrq + l + dd->rhf_offset;
if (dd->flags & QIB_NODMA_RTAIL) { if (dd->flags & QIB_NODMA_RTAIL) {
u32 seq = qib_hdrget_seq(rhf_addr); u32 seq = qib_hdrget_seq(rhf_addr);