diff options
| author | Dave Olson <dave.olson@qlogic.com> | 2007-08-09 15:18:48 -0700 |
|---|---|---|
| committer | Roland Dreier <rolandd@cisco.com> | 2007-10-09 20:44:20 -0700 |
| commit | 9ef8617af77136e743e5dd4b081a61797888a977 (patch) | |
| tree | 93999550ddf98ff3c743fd27a7bd942d8cbfdf09 /drivers/infiniband | |
| parent | 1793b4771d258c93ed86a6356c95cac418781fdd (diff) | |
IB/ipath: Correctly describe workaround for TID write chip bug
This is a comment change, only, correcting the comment to match the
implemented workaround, rather than the original workaround, and
clarifying why it's needed.
Signed-off-by: Dave Olson <dave.olson@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Diffstat (limited to 'drivers/infiniband')
| -rw-r--r-- | drivers/infiniband/hw/ipath/ipath_iba6120.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/drivers/infiniband/hw/ipath/ipath_iba6120.c b/drivers/infiniband/hw/ipath/ipath_iba6120.c index a324c6f7aeb..d43f0b3a43f 100644 --- a/drivers/infiniband/hw/ipath/ipath_iba6120.c +++ b/drivers/infiniband/hw/ipath/ipath_iba6120.c @@ -1143,11 +1143,14 @@ static void ipath_pe_put_tid(struct ipath_devdata *dd, u64 __iomem *tidptr, pa |= 2 << 29; } - /* workaround chip bug 9437 by writing each TID twice - * and holding a spinlock around the writes, so they don't - * intermix with other TID (eager or expected) writes - * Unfortunately, this call can be done from interrupt level - * for the port 0 eager TIDs, so we have to use irqsave + /* + * Workaround chip bug 9437 by writing the scratch register + * before and after the TID, and with an io write barrier. + * We use a spinlock around the writes, so they can't intermix + * with other TID (eager or expected) writes (the chip bug + * is triggered by back to back TID writes). Unfortunately, this + * call can be done from interrupt level for the port 0 eager TIDs, + * so we have to use irqsave locks. */ spin_lock_irqsave(&dd->ipath_tid_lock, flags); ipath_write_kreg(dd, dd->ipath_kregs->kr_scratch, 0xfeeddeaf); |