On 03/14/2016 05:27 AM, Finn Thain wrote: > This change brings a number of improvements: fewer macros, better test > coverage, simpler code and sane Kconfig options. The downside is a small > chance of incompatibility (which seems unavoidable). > > CONFIG_SCSI_GENERIC_NCR53C400 exists to enable or inhibit pseudo DMA > transfers when the driver is used with 53C400-compatible cards. Thanks to > Ondrej Zary's patches, PDMA now works which means it can be enabled > unconditionally. > > Due to bad design, CONFIG_SCSI_GENERIC_NCR53C400 ties together unrelated > functionality as it sets both PSEUDO_DMA and BIOSPARAM macros. This patch > effectively enables PSEUDO_DMA and disables BIOSPARAM. > > The defconfigs and the Kconfig default leave CONFIG_SCSI_GENERIC_NCR53C400 > undefined. Red Hat 9 and CentOS 2.1 were the same. This leaves both > PSEUDO_DMA and BIOSPARAM disabled. The effect of this patch should be > better performance from enabling PSEUDO_DMA. > > On the other hand, Debian 4 and SLES 10 had CONFIG_SCSI_GENERIC_NCR53C400 > enabled, so both PSEUDO_DMA and BIOSPARAM were enabled. This patch might > affect configurations like this by disabling BIOSPARAM. My best guess is > that this could be a problem only in the vanishingly rare case that > 1) the CHS values stored in the boot device partition table are wrong and > 2) a 5380 card is in use (because PDMA on 53C400 used to be broken). > > Signed-off-by: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx> > > --- > Reviewed-by: Hannes Reinecke <hare@xxxxxxxx> And don't worry about SLES10; we won't backport your fixes to _that_. Cheers, Hannes -- Dr. Hannes Reinecke Teamlead Storage & Networking hare@xxxxxxx +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG Nürnberg) -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
