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From: prylowski@metasoft•pl (Rafal Prylowski)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 1/3] PATA host controller driver for ep93xx
Date: Mon, 02 Apr 2012 11:28:36 +0200	[thread overview]
Message-ID: <4F797144.400@metasoft.pl> (raw)
In-Reply-To: <201204020808.34529.arnd@arndb.de>

On 2012-04-02 10:08, Arnd Bergmann wrote:
> On Monday 02 April 2012, Rafal Prylowski wrote:
>>
>> I selected "PATA SFF controllers with BMDMA" list because the driver
>> inherits .ata_bmdma_port_ops (this is in libata-sff.c, which is compiled
>> only if ATA_SFF is set).
> 
> Ok, I see. Is it actually the right one to inherit from though?
> 
> You end up overriding most of the opterations that are set there again,
> the only ones that you use are:
> 
> ata_bmdma_error_handler, ata_bmdma_post_internal_cmd, ata_bmdma_qc_issue,
> ata_sff_qc_fill_rtf, ata_sff_freeze, ata_sff_thaw, ata_sff_prereset,
> ata_sff_postreset and ata_sff_error_handler.
> 
> Are you sure they are all doing the righ thing on your hardware? If
> not, it might be better to explicitly just set the ones you need and
> see if that still uses any sff functions in the end.
> 
> 	Arnd

I think that inheriting from .ata_bmdma_port_ops is quite reasonable.
Another option would be to inherit from .ata_sff_port_ops and implement
.qc_issue hook (like in pata_octeon_cf.c), but this way we end up
reimplementing the same things from libata-sff.c, IMHO. Also, I think
that it's not possible to write PATA driver without this SFF stuff
(at least for me - I'm not libata expert).
I reviewed code paths from all hooks used in ep93xx driver to make sure
that we use only ep93xx_pata_read/ep93xx_pata_write instead of ioread/iowrite.

RP

  reply	other threads:[~2012-04-02  9:28 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-03-29  8:10 [PATCH 0/3] Add PATA host controller support for Cirrus Logic EP93xx CPU Rafal Prylowski
2012-03-29  8:17 ` [PATCH 1/3] PATA host controller driver for ep93xx Rafal Prylowski
2012-03-29 17:25   ` H Hartley Sweeten
2012-03-30  8:13     ` Rafal Prylowski
2012-03-29 22:21   ` Ryan Mallon
2012-03-30 10:13     ` Rafal Prylowski
2012-03-29 22:24   ` Ryan Mallon
2012-03-30  8:19     ` Rafal Prylowski
2012-03-30 20:18   ` Arnd Bergmann
2012-04-02  7:52     ` Rafal Prylowski
2012-04-02  8:08       ` Arnd Bergmann
2012-04-02  9:28         ` Rafal Prylowski [this message]
2012-04-02 10:24           ` Arnd Bergmann
2012-04-03  1:50       ` Ryan Mallon
2012-04-03  7:41         ` Arnd Bergmann
2012-03-29  8:19 ` [PATCH 2/3] ep93xx: IDE driver platform support code Rafal Prylowski
2012-03-29 16:26   ` H Hartley Sweeten
2012-03-30  8:29     ` Rafal Prylowski
2012-03-29  8:20 ` [PATCH 3/3] ep93xx: Add IDE support to edb93xx boards Rafal Prylowski
2012-03-29 16:32   ` H Hartley Sweeten
2012-03-30  8:32     ` Rafal Prylowski

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