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| author | Ursula Braun <ubraun@linux.vnet.ibm.com> | 2018-02-09 11:03:49 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-02-09 14:30:23 -0500 |
| commit | 89271c65edd599207dd982007900506283c90ae3 (patch) | |
| tree | 8914755732ad1d2d5eca6c0be6d64d05806eb23d | |
| parent | 0bf7800f1799b5b1fd7d4f024e9ece53ac489011 (diff) | |
| download | linux-89271c65edd599207dd982007900506283c90ae3.tar.bz2 | |
s390/qeth: fix underestimated count of buffer elements
For a memory range/skb where the last byte falls onto a page boundary
(ie. 'end' is of the form xxx...xxx001), the PFN_UP() part of the
calculation currently doesn't round up to the next PFN due to an
off-by-one error.
Thus qeth believes that the skb occupies one page less than it
actually does, and may select a IO buffer that doesn't have enough spare
buffer elements to fit all of the skb's data.
HW detects this as a malformed buffer descriptor, and raises an
exception which then triggers device recovery.
Fixes: 2863c61334aa ("qeth: refactor calculation of SBALE count")
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/s390/net/qeth_core.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h index db42107bf2f5..c33fbc4c2e91 100644 --- a/drivers/s390/net/qeth_core.h +++ b/drivers/s390/net/qeth_core.h @@ -846,7 +846,7 @@ struct qeth_trap_id { */ static inline int qeth_get_elements_for_range(addr_t start, addr_t end) { - return PFN_UP(end - 1) - PFN_DOWN(start); + return PFN_UP(end) - PFN_DOWN(start); } static inline int qeth_get_micros(void) |