sparc64/164226: Data corruption on 9.0-RELEASE when reading from CDROM

[Marius Strobl]

The following reply was made to PR sparc64/164226; it has been noted by GNATS.

From: Marius Strobl <marius at alchemy.franken.de>
To: Alexander Motin <mav at FreeBSD.org>
Cc: freebsd-gnats-submit at FreeBSD.org, "C. P. Ghost" <cpghost at cordula.ws>
Subject: Re: sparc64/164226: Data corruption on 9.0-RELEASE when reading from CDROM
Date: Fri, 20 Jan 2012 20:32:54 +0100

 On Fri, Jan 20, 2012 at 08:13:38PM +0200, Alexander Motin wrote:
 > On 20.01.2012 19:51, Marius Strobl wrote:
 > >Alexander, could you please look into this?
 > >Apparently, using cd(4) with ATA_CAM on sparc64 causes seemingly
 > >random data corruption while using the same hardware with acd(4)
 > >doesn't. Also cd(4) works just fine with SPI CD-ROMs. This affects
 > >CD-ROMs connected to both AcerLabs M5229 and CMD 646.
 > >Btw., apparently hw.ata.ata_dma and w.ata.atapi_dma no longer
 > >work when using ATA_CAM as ata_getparam() isn't called in the
 > >first place. On a quick glance hw.ata.ata_dma_check_80pin and
 > >hw.ata.wc probably also are no longer available with ATA_CAM.
 > >Is there an alternative to these tunables to achieve the same
 > >when using ATA_CAM?
 > 
 > hw.ata.ata_dma and hw.ata.atapi_dma are indeed no longer exist. But 
 > hint.ata.X.mode and hint.ata.X.devX.mode are working. In run tame it can 
 > be done via `camcontrol negotiate cd0 -U -M mode; camcontrol rescan X`, 
 > where X is a CAM bus number.
 > 
 > hw.ata.ata_dma_check_80pin still exist, but CAM ATA transport is no 
 > longer look on whet device thinks about cable type. It is tricky in SATA 
 > world. Cable type is checked only from controller driver side now. Looks 
 > like none of mentioned controller drivers are doing it.
 > 
 > hw.ata.wc was replaced by kern.cam.ada.write_cache and 
 > kern.cam.ada.X.write_cache.
 > 
 > I would start experiments from limiting transfer speed manually.
 > 
 
 Hrm, limitting the mode to PIO avoids the data corruption with
 ATA_CAM.
 
 Marius