ATA anomaly Question

Matthew Dillon dillon at apollo.backplane.com
Sat Mar 19 10:45:27 PST 2005


:
:Testing various PATA & SATA controllers under DragonFlyBSD 1.1 STABLE of 
:15 March:
:
:- Anomalies:
:
:Add-on controllers, SATA:
:
:- booting may report in dmesg: 'DMA limited to UDMA 33, non-ATA66 cable 
:or device'
:
:None of the SATA controllers under test have PATA ports.

   Just ignore it.  It's because our ATA driver isn't really all that
   SATA-aware, so it is doing certain ATA checks that don't apply to
   SATA.  The SATA controller ignores it.

:Same message can also occur with actual PATA controllers when the cable 
:is a proper UDMA-100,'
:and can do so erratically when different 'race' of UDMA-100 drives are 
:on same cables as Master/Slave.
:..
:Bill

    Typically the cable is reversed (motherboard side is connected to the
    drive and the drive side is connected to the motherboard) when the
    message occurs for a standard PATA drive and the cable is 
    UDMA-capable.
    
					-Matt
					Matthew Dillon 
					<dillon at xxxxxxxxxxxxx>





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