From: Jeff Garzik <jeff@garzik.org>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Tejun Heo <htejun@gmail.com>,
linux-ide@vger.kernel.org, liml@rtr.ca, albertl@mail.com,
jens.axboe@oracle.com
Subject: Re: [PATCH 05/14] libata: make ->data_xfer return the number of consumed bytes
Date: Thu, 29 Nov 2007 14:36:30 -0500 [thread overview]
Message-ID: <474F14BE.2050502@garzik.org> (raw)
In-Reply-To: <20071129182409.2fcd66d6@the-village.bc.nu>
Alan Cox wrote:
>> DMA alignment is host restriction so I think it belongs to ata_host if
>> we ever need it. Do you know of any controller which require such
>> thing? No need to add complexity when it's not necessary.
>
> If we ever get the blasted inic162x working then that appears to have
> some alignment limits. At least the docs say the DMA buffers must be quad
> word aligned and sized (although it doesn't describe what occurs if the
> total length of xfer disagrees with the buffers)
Most DMA has alignment limits, for the front not the back of the buffer.
Jeff
next prev parent reply other threads:[~2007-11-29 19:36 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-11-29 14:33 [PATCHSET] libata: improve ATAPI data transfer handling, take #2 Tejun Heo
2007-11-29 14:33 ` [PATCH 01/14] libata: update atapi_eh_request_sense() such that lbam/lbah contains buffer size Tejun Heo
2007-11-29 15:51 ` Alan Cox
2007-12-04 19:27 ` Jeff Garzik
2007-12-05 0:47 ` Tejun Heo
2007-11-29 14:33 ` [PATCH 02/14] cdrom: add more GPCMD_* constants Tejun Heo
2007-11-29 14:33 ` [PATCH 03/14] libata: rename ATA_PROT_ATAPI_* to ATAPI_PROT_* Tejun Heo
2007-11-29 15:52 ` Alan Cox
2007-11-29 14:33 ` [PATCH 04/14] libata: add ATAPI_* cmd types and implement atapi_cmd_type() Tejun Heo
2007-11-29 14:33 ` [PATCH 05/14] libata: make ->data_xfer return the number of consumed bytes Tejun Heo
2007-11-29 15:55 ` Alan Cox
2007-11-29 16:06 ` Tejun Heo
2007-11-29 17:42 ` Alan Cox
2007-11-29 18:00 ` Tejun Heo
2007-11-29 18:24 ` Alan Cox
2007-11-29 18:57 ` Mark Lord
2007-11-29 19:37 ` Jeff Garzik
2007-11-29 19:36 ` Jeff Garzik [this message]
2007-11-29 21:22 ` Alan Cox
2007-12-04 19:30 ` Jeff Garzik
2007-12-05 0:49 ` Tejun Heo
2007-12-05 1:05 ` Jeff Garzik
2007-11-29 14:33 ` [PATCH 06/14] libata: improve ATAPI draining Tejun Heo
2007-11-29 15:59 ` Alan Cox
2007-11-29 16:09 ` Tejun Heo
2007-11-29 16:42 ` Tejun Heo
2007-11-29 17:40 ` Alan Cox
2007-11-29 18:11 ` Tejun Heo
2007-11-29 18:19 ` Alan Cox
2007-12-04 10:06 ` Albert Lee
2007-12-05 1:00 ` Tejun Heo
2007-11-29 14:33 ` [PATCH 07/14] libata: make atapi_request_sense() use sg Tejun Heo
2007-11-29 14:33 ` [PATCH 08/14] libata: kill non-sg DMA interface Tejun Heo
2007-11-29 16:00 ` Alan Cox
2007-12-04 19:31 ` Jeff Garzik
2007-12-05 1:02 ` Tejun Heo
2007-11-29 14:33 ` [PATCH 09/14] libata: change ATA_QCFLAG_DMAMAP semantics Tejun Heo
2007-11-29 14:33 ` [PATCH 10/14] libata: convert to chained sg Tejun Heo
2007-11-29 14:33 ` [PATCH 11/14] libata: add qc->dma_nbytes Tejun Heo
2007-11-29 16:02 ` Alan Cox
2007-12-04 19:33 ` Jeff Garzik
2007-12-05 1:02 ` Tejun Heo
2007-11-29 14:33 ` [PATCH 12/14] libata: implement ATAPI drain buffer Tejun Heo
2007-11-29 14:33 ` [PATCH 13/14] libata: implement ATAPI per-command-type DMA horkages Tejun Heo
2007-11-29 16:04 ` Alan Cox
2007-11-29 16:10 ` Tejun Heo
2007-11-29 14:33 ` [PATCH 14/14] libata: use PIO for misc ATAPI commands Tejun Heo
2007-11-29 16:05 ` Alan Cox
2007-11-29 16:14 ` Tejun Heo
2007-11-29 16:16 ` Tejun Heo
2007-11-29 18:55 ` Mark Lord
2007-11-29 22:52 ` Tejun Heo
2007-11-30 1:03 ` Mark Lord
2007-11-30 1:34 ` Tejun Heo
2007-11-30 4:19 ` Mark Lord
2007-11-30 13:40 ` Alan Cox
2007-11-30 13:59 ` Tejun Heo
2007-11-30 14:12 ` Jeff Garzik
2007-11-30 15:36 ` Alan Cox
2007-11-30 13:09 ` Alan Cox
2007-11-29 17:38 ` Alan Cox
2007-12-04 19:34 ` Jeff Garzik
2007-12-05 1:14 ` Tejun Heo
2007-12-05 12:47 ` Alan Cox
2007-12-05 13:03 ` Tejun Heo
2007-12-05 14:01 ` Alan Cox
2007-12-05 14:22 ` Tejun Heo
2007-12-05 14:46 ` Alan Cox
2007-12-05 15:13 ` Tejun Heo
2007-12-05 18:52 ` Jeff Garzik
2007-12-06 11:03 ` Petr Vandrovec
2007-12-06 11:10 ` Tejun Heo
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