mirror of
https://github.com/torvalds/linux.git
synced 2026-06-28 00:55:49 +02:00
31cc23b349
Controllers which support PMP have various restrictions on which combinations of commands are allowed to what number of devices concurrently. This patch implements ops->qc_defer() which determines whether a qc can be issued at the moment or should be deferred. If the function returns ATA_DEFER_LINK, the qc will be deferred until a qc completes on the link. If ATA_DEFER_PORT, until a qc completes on any link. The defer conditions are advisory and in general ATA_DEFER_LINK can be considered as lower priority deferring than ATA_DEFER_PORT. ops->qc_defer() replaces fixed ata_scmd_need_defer(). For standard NCQ/non-NCQ exclusion, ata_std_qc_defer() is implemented. ahci and sata_sil24 are converted to use ata_std_qc_defer(). ops->qc_defer() is heavier than the original mechanism because full qc is prepped before determining to defer it, but various information is needed to determine defer conditinos and fully translating a qc is the only way to supply such information in generic manner. IMHO, this shouldn't cause any noticeable performance issues as * for most cases deferring occurs rarely (except for NCQ-aware cmd-switching PMP) * translation itself isn't that expensive * once deferred the command won't be repeated until another command completes which usually is a very long time cpu-wise. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jeff Garzik <jeff@garzik.org> |
||
|---|---|---|
| .. | ||
| acpi | ||
| asm-alpha | ||
| asm-arm | ||
| asm-avr32 | ||
| asm-blackfin | ||
| asm-cris | ||
| asm-frv | ||
| asm-generic | ||
| asm-h8300 | ||
| asm-ia64 | ||
| asm-m32r | ||
| asm-m68k | ||
| asm-m68knommu | ||
| asm-mips | ||
| asm-parisc | ||
| asm-powerpc | ||
| asm-ppc | ||
| asm-s390 | ||
| asm-sh | ||
| asm-sh64 | ||
| asm-sparc | ||
| asm-sparc64 | ||
| asm-um | ||
| asm-v850 | ||
| asm-x86 | ||
| asm-xtensa | ||
| crypto | ||
| keys | ||
| linux | ||
| math-emu | ||
| media | ||
| mtd | ||
| net | ||
| pcmcia | ||
| rdma | ||
| rxrpc | ||
| scsi | ||
| sound | ||
| video | ||
| xen | ||
| Kbuild | ||