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[SCSI] mpt2sas: Fix possible integer truncation of cpu_count

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When computing reply_queue_count (the number of MSI-X vectors to use),
the driver does

	ioc->reply_queue_count = min_t(u8, ioc->cpu_count,
	    ioc->msix_vector_count);

However, on a big machine, ioc->cpu_count could be outside the range
that fits in a u8; eg a system with 256 CPUs will end up
reply_queue_count set to 0.

Fix this by calculating the minimum as ints and then letting the
assignment to reply_queue_count handle integer demotion.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Acked-by: "Nandigama, Nagalakshmi" <Nagalakshmi.Nandigama@lsi.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
This commit is contained in:
Roland Dreier 2011-11-30 16:30:33 -08:00 committed by James Bottomley
parent c24a1710d1
commit 2f73b9a896
1 changed files with 1 additions and 1 deletions
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2
drivers/scsi/mpt2sas/mpt2sas_base.c
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@ -1407,7 +1407,7 @@ _base_enable_msix(struct MPT2SAS_ADAPTER *ioc)
if (_base_check_enable_msix(ioc) != 0)
goto try_ioapic;
ioc->reply_queue_count = min_t(u8, ioc->cpu_count,
ioc->reply_queue_count = min_t(int, ioc->cpu_count,
ioc->msix_vector_count);
entries = kcalloc(ioc->reply_queue_count, sizeof(struct msix_entry),