Messages in this thread | | | Date | Wed, 14 May 2003 00:37:00 -0700 | From | Mike Anderson <> | Subject | Re: drivers/scsi/aic7xxx/aic7xxx_osm.c: warning is error |
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Justin T. Gibbs [gibbs@scsiguy.com] wrote: > Comments have indicated since the 2.4.X days that Linux will never allocate > segments that cross a 4GB boundary. If this is truely enforced, then this > code can just be removed. It was only added out of paranoia (hence the > printf) while adding high address support to the driver.
Jens can give the more complete answer on enforcement, and also correct any mis-statements I made.
Base on the queue values below the aic7xxx driver should see the following characteristics on IO. The IO should be for no more than 8k made up of no more than 128 sg entries with no segment crossing the seg_boundary_mask.
Adaptec AIC7xxx driver version: 6.2.33 scsi_alloc_queue: queue for aic7xxx bounce_pfn: 0xfffff bounce_gfp: 0x10 (GFP_NOIO) queue_flags: 0x1 (QUEUE_FLAG_QUEUED) max_sectors: 0x2000 (8192) max_phys_segments: 0x80 (128) max_hw_segments: 0x80 (128) hardsect_size: 0x200 (512) max_segment_size: 0x10000 (65536) seg_boundary_mask: 0xffffffff dma_alignment: 0x1ff (511)
-andmike -- Michael Anderson andmike@us.ibm.com
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