On Fri, Sep 15, 2006 at 09:12:33AM -0600, Fajun Chen wrote: > Hi, > > I'm trying to speed up the SATA hotplug sequence so I can measure the > disk spinup time more accurately. I noticed two delays which may be > unnecessary in SATA hotplug: > 1. About 4-5 seconds delay during power cycle (power down then power > up) as shown below (detail log at the end): > [65642.680000] ata_eh_prep_resume: ENTER > [65642.680000] ata_eh_prep_resume: EXIT > [65642.680000] __ata_port_freeze: ata2 port frozen > [65646.970000] ata2: soft resetting port > [65646.970000] sil24_softreset: ENTER > Question: where is the delay introduced and can we eliminate this delay? It's probably waiting for ATA_BUSY to clear in prereset. > 2. Soft reset fails sometimes then followed by a successful hard reset. > Question: may I do hard reset to start with and where is the best > place to change this? I know sata spec recommend attempting less > intrusive recovery procedure first, but I need to eliminate as much > unnecessary delay as possible. ATA_FLAG_HRST_TO_RESUME. You probably also want to tweak ATA_SPINUP_WAIT. > Is there any other place in new eh where SATA hotplug can be optimized? Too many to point out. :-) -- tejun - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
