diff options
author | Dave Olson <dave.olson@qlogic.com> | 2007-08-09 18:18:48 -0400 |
---|---|---|
committer | Roland Dreier <rolandd@cisco.com> | 2007-10-09 23:44:20 -0400 |
commit | 9ef8617af77136e743e5dd4b081a61797888a977 (patch) | |
tree | 93999550ddf98ff3c743fd27a7bd942d8cbfdf09 /drivers/infiniband/hw | |
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/hw')
-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 a324c6f7aeba..d43f0b3a43fe 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, | |||
1143 | pa |= 2 << 29; | 1143 | pa |= 2 << 29; |
1144 | } | 1144 | } |
1145 | 1145 | ||
1146 | /* workaround chip bug 9437 by writing each TID twice | 1146 | /* |
1147 | * and holding a spinlock around the writes, so they don't | 1147 | * Workaround chip bug 9437 by writing the scratch register |
1148 | * intermix with other TID (eager or expected) writes | 1148 | * before and after the TID, and with an io write barrier. |
1149 | * Unfortunately, this call can be done from interrupt level | 1149 | * We use a spinlock around the writes, so they can't intermix |
1150 | * for the port 0 eager TIDs, so we have to use irqsave | 1150 | * with other TID (eager or expected) writes (the chip bug |
1151 | * is triggered by back to back TID writes). Unfortunately, this | ||
1152 | * call can be done from interrupt level for the port 0 eager TIDs, | ||
1153 | * so we have to use irqsave locks. | ||
1151 | */ | 1154 | */ |
1152 | spin_lock_irqsave(&dd->ipath_tid_lock, flags); | 1155 | spin_lock_irqsave(&dd->ipath_tid_lock, flags); |
1153 | ipath_write_kreg(dd, dd->ipath_kregs->kr_scratch, 0xfeeddeaf); | 1156 | ipath_write_kreg(dd, dd->ipath_kregs->kr_scratch, 0xfeeddeaf); |