From: Jeff Garzik <jgarzik@pobox.com>
To: "Jung-Ik (John) Lee" <jilee@google.com>
Cc: Robert Hancock <hancockrwd@gmail.com>,
Daniel Walker <dwalker@fifo99.com>,
linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org,
Grant Grundler <grundler@google.com>,
Gwendal Grignou <gwendal@google.com>,
Eric Uhrhane <ericu@google.com>, Tejun Heo <tj@kernel.org>,
Alan Cox <alan@linux.intel.com>
Subject: Re: [PATCH] libata: Add pata_atp867x driver for Artop/Acard ATP867X controllers
Date: Sat, 12 Sep 2009 20:38:02 -0400 [thread overview]
Message-ID: <4AAC3EEA.1080605@pobox.com> (raw)
In-Reply-To: <8b5805ff0909121717w1516c273k2a568779b9c31662@mail.gmail.com>
On 09/12/2009 08:17 PM, Jung-Ik (John) Lee wrote:
> On Sat, Sep 12, 2009 at 9:49 AM, Robert Hancock<hancockrwd@gmail.com> wrote:
>> On 09/12/2009 04:59 AM, Jung-Ik (John) Lee wrote:
>>
>> (snip)
>>
>> Looks mostly reasonable to me, other than a few issues:
>>
>>> +static void atp867x_set_piomode(struct ata_port *ap, struct ata_device
>>> *adev)
>>> +{
>>> + struct ata_device *peer = ata_dev_pair(adev);
>>> + struct atp867x_priv *dp = ap->private_data;
>>> + u8 speed = adev->pio_mode;
>>> + struct ata_timing t, p;
>>> + int T, UT;
>>> + u8 b;
>>> +
>>> + T = 1000000000 / 33333;
>>> + UT = T/4;
>>> +
>>> + switch (speed) {
>>> + case XFER_PIO_4:
>>> + case XFER_PIO_3:
>>> + case XFER_PIO_2:
>>> + case XFER_PIO_1:
>>> + case XFER_PIO_0:
>>> + case XFER_PIO_SLOW:
>>> + break;
>>> + default:
>>> + printk(KERN_WARNING "ATP867X: Unsupported speed %#x."
>>> + " Default to XFER_PIO_0.\n", (unsigned)speed);
>>> + speed = XFER_PIO_0;
>>> + }
>>> +
>>> + ata_timing_compute(adev, speed,&t, T, UT);
>>> + if (peer&& peer->pio_mode) {
>>> + ata_timing_compute(peer, peer->pio_mode,&p, T, UT);
>>> + ata_timing_merge(&p,&t,&t, ATA_TIMING_8BIT);
>>> + }
>>> +
>>> + b = inb(dp->dma_mode);
>>> + if (adev->devno& 1)
>>> + b = (b& ~ATP867X_IO_DMAMODE_SLAVE_MASK);
>>> + else
>>> + b = (b& ~ATP867X_IO_DMAMODE_MSTR_MASK);
>>> + outb(b, dp->dma_mode);
>>> +
>>> +#ifdef ATP867X_NO_HACK_PIOMODE
>>> + b = atp867x_get_active_clocks_shifted(t.active) |
>>> + atp867x_get_recover_clocks_shifted(t.recover);
>>> +#else
>>> + /*
>>> + * magic value that works (from doc 6.4, 6.6.9)
>>> + */
>>> + b = 0x31;
>>> +#endif
>>
>> What's the purpose of this ifdef?
>
> The magic value part must go. I'll update the patch.
>
>>
>>> + if (dp->pci66mhz)
>>> + b += 0x10;
>>> +
>>> + if (adev->devno& 1)
>>> + outb(b, dp->slave_piospd);
>>> + else
>>> + outb(b, dp->mstr_piospd);
>>> +
>>> + /*
>>> + * use the same value for comand timing as for PIO timimg
>>> + */
>>> + outb(b, dp->eightb_piospd);
>>> +}
>>> +
>>> +static int atp867x_cable_detect(struct ata_port *ap)
>>> +{
>>> + return ATA_CBL_PATA40_SHORT;
>>> +}
>>
>> Doesn't the controller have a way to do proper 80-wire cable detection?
>
> No programmatic way. libata.force should be used for other configurations.
Ideally you would use ATA_CBL_PATA_UNK / ata_cable_unknown, but it seems
that ATA_CBL_PATA_UNK has grown rather useless in the current kernel.
We should probably (a) update libata-core/libata-sff to do something
intelligent with ATA_CBL_PATA_UNK, and (b) use ATA_CBL_PATA_UNK in
pata_atp867x.
But yes, libata.force works as well. It just seems like we are losing
an opportunity to accept an existing BIOS-configured 80-wire cable
configuration by hardcoding ATA_CBL_PATA40_SHORT.
Also, a specific note -- atp867x_cable_detect() should be moved into
drivers/ata/libata-core.c and made generic. We have ata_cable_xxx
versions for everything except 40-short, it seems.
Jeff
next prev parent reply other threads:[~2009-09-13 0:38 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-12 2:06 [PATCH] libata: Add pata_atp867x driver for Artop/Acard ATP867X controllers Jung-Ik (John) Lee
2009-09-12 2:06 ` Jung-Ik (John) Lee
2009-09-12 2:14 ` Daniel Walker
2009-09-12 10:59 ` Jung-Ik (John) Lee
2009-09-12 10:59 ` Jung-Ik (John) Lee
2009-09-12 16:49 ` Robert Hancock
2009-09-13 0:17 ` Jung-Ik (John) Lee
2009-09-13 0:17 ` Jung-Ik (John) Lee
2009-09-13 0:26 ` Jung-Ik (John) Lee
2009-09-13 0:26 ` Jung-Ik (John) Lee
2009-09-13 0:31 ` Jeff Garzik
2009-09-13 0:37 ` Jung-Ik (John) Lee
2009-09-13 0:37 ` Jung-Ik (John) Lee
2009-09-13 0:55 ` Jeff Garzik
2009-09-13 2:41 ` Jung-Ik (John) Lee
2009-09-13 2:41 ` Jung-Ik (John) Lee
2009-09-13 3:12 ` Jeff Garzik
2009-09-13 4:55 ` Jung-Ik (John) Lee
2009-09-13 4:55 ` Jung-Ik (John) Lee
2009-09-13 5:50 ` Robert Hancock
2009-09-13 5:50 ` Robert Hancock
2009-09-15 4:32 ` Jung-Ik (John) Lee
2009-09-15 4:32 ` Jung-Ik (John) Lee
2009-09-17 20:51 ` Jeff Garzik
2009-09-13 0:38 ` Jeff Garzik [this message]
2009-09-13 0:50 ` Jung-Ik (John) Lee
2009-09-13 0:50 ` Jung-Ik (John) Lee
2009-09-15 0:38 ` Alan Cox
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4AAC3EEA.1080605@pobox.com \
--to=jgarzik@pobox.com \
--cc=alan@linux.intel.com \
--cc=dwalker@fifo99.com \
--cc=ericu@google.com \
--cc=grundler@google.com \
--cc=gwendal@google.com \
--cc=hancockrwd@gmail.com \
--cc=jilee@google.com \
--cc=linux-ide@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=tj@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.