From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: sata_nv and 2.6.24 (was Re: fixed a bug of adma in rhel4u5 with HDS7250SASUN500G.) Date: Wed, 23 Jan 2008 20:42:16 -0500 Message-ID: <4797ECF8.9000606@garzik.org> References: <4781F008.9070404@gmail.com> <4782422C.8020202@rtr.ca> <4782B73B.8080309@shaw.ca> <4782BC48.4000309@gmail.com> <4782C008.3030902@shaw.ca> <4782CB62.7040901@gmail.com> <4782CEF9.3040708@gmail.com> <4782DFFE.50301@shaw.ca> <4782E5A8.9010305@gmail.com> <4782E63E.1000606@gmail.com> <4782E78F.9050205@shaw.ca> <4782E912.1050204@gmail.com> <4783493A.7070800@gmail.com> <47838B57.8020407@shaw.ca> <47842A54.2060107@gmail.com> <47842ABA.2060605@gmail.com> <47844471.4070705@shaw.ca> <47845708.6060900@gmail.com> <478567D8.10601@shaw.ca> <15F501D1A78BD343BE8F4D8DB854566B1BFE2ABF@hkemmail01.nvidia.com> <478812C9.1000901@shaw.ca> <15F501D1A78BD343BE8F4D8DB854566B1BFE2AC0@hkemmail01.nvidia.com> <478AF10D.5080805@shaw.ca> <479709BE.2090707@garzik.org> <479752D7.4020206@shaw.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <479752D7.4020206@shaw.ca> Sender: linux-kernel-owner@vger.kernel.org To: Robert Hancock Cc: Kuan Luo , Tejun Heo , Mark Lord , IDE/ATA development list , Allen Martin , Peer Chen , linux-kernel , David Milburn List-Id: linux-ide@vger.kernel.org Robert Hancock wrote: > Jeff Garzik wrote: >> Ping... sata_nv status is still a bit open for 2.6.24, and I would >> like to move us forward a bit. >> >> * Kuan's patch... it has been confirmed (and is needed), correct? >> can someone work up a good patch for 2.6.24? The only one I ever >> received was badly word-wrapped, and at the time, Robert seemed >> uncertain of it, so I waited. > > I can get you one later today hopefully. > >> >> * ADMA ATAPI 4GB issues... playing tricks with the ordering of >> allocations and DMA masks is just way too fragile. We just cannot >> guarantee that all allocators work that way. The obvious solution to >> me seems to be hardcoding the consistent DMA mask to 32-bit, but using >> 64-bit for regular dma mask if-and-only-if ADMA is enabled. > > That's not enough to fix the problem since there's issues with actual > transfer data being allocated above 4GB as well, not just the consistent > allocations (it appears that blk_queue_bounce_limit setting to 32-bit > doesn't prevent this on x86_64). Either we play some funky games with > changing the DMA mask of the entire device to 32-bit if either port is > in ATAPI mode (which blew up when I tried it) or we add the ability to > set the DMA mask independently on each port (like by setting the mask on > the SCSI device and using that for DMA mapping instead) which requires > core changes. Its all funky games that no other driver is doing... There is one guaranteed to work scenario -- set all masks and bounce limits etc. to 32-bit. There is also one highly-likely-to-work scenario, disabling ADMA by default. >> * it sure seems like there are other open sata_nv ADMA issues -- can >> we hard-confirm or deny this? bugzilla wasn't very helpful for me. >> It doesn't seem like we can disable ADMA (to solve those issues) and >> get enough test time in (which is what I said a week (or more?) ago >> too...) > > The NCQ/non-NCQ command switching issue is still hitting some people > (last I heard Kuan was looking into this), also there's a hotplug issue > that Tejun reported.. The former implies we need to disable swncq for 2.6.24, if it's not stable yet. Jeff