https://bugzilla.novell.com/show_bug.cgi?id=445856 Summary: Efika ATA DMA for 11.1 please Product: openSUSE 11.1 Version: Factory Platform: Other OS/Version: Other Status: NEW Severity: Enhancement Priority: P5 - None Component: Kernel AssignedTo: bnc-team-screening@forge.provo.novell.com ReportedBy: matt@genesi-usa.com QAContact: qa@suse.de CC: olh@novell.com, pczanik@genesi-usa.com Found By: --- Please include ATA DMA patches from Grant Likely (and the appropriate BestComm Kconfig fixes). Will be attached to this report (1/3) Purpose: enables UDMA operation for ATA disks on Efika, meaning faster (up to ~33MB/s, from ~1.2MB/s) access and lower (5-10% from 40-80%) CPU usage. This Problems: none reported. Efika DMA support will not be enabled by default because of missing entries in the Open Firmware device tree. However is is recommended not to enable them by default as some disks and CompactFlash adapters (and cards) do not implement DMA lines properly and these may cause some havoc (more than usual for a should-be-blacklisted disk!). ATA operation has some undocumented errata re LocalPlus operation but Efika does not implement ATA and LocalPlus together. ATA operation affected by documented errata re FIFO alarms but these have not been reported and the driver implements several locks at points to safeguard this. ATA task priority must be raised (driver implements this) to handle this, may affect audio quality on current (experimental) audio driver and cause minor network performance changes during extremely heavy disk activity due to the operation of the BestComm DMA controller. Users can enable it by adding a simple Forth script to their boot process; this should NOT be implemented as a kernel patch for arch/powerpc/boot/prom_init.c as with other fixes since it would take away the user configurability and make the kernel and device tree implementations and changes a moving target. ~~~~~~~~ \ FORTH s" /builtin/ata" find-device 4 encode-int s" udma-mode" property 4 encode-int s" mwdma-mode" property device-end ~~~~~~~~ This also allows DMA mode forcing ABOVE AND BEYOND libata.dma and libata.modes kernel arguments. Genesi will supply DUD and user support for this patchset on the Wiki as we have for all Efika releases (11.0 had a DUD to mkzimage the kernel), and provide package additions, however we respectfully request that the kernel patch be maintained by the SUSE kernel team. Since it is not intrusive and does not change ANY behaviour as compared to old releases without the above properties it cannot impact system stability by default. Attached: Patch 1/3 - BestComm ATA task fixes (descriptor dst/src reversed) -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.