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From: "Jung-Ik (John) Lee" <jilee@google.com>
Date: Sat, 12 Sep 2009 17:17:08 -0700
Message-ID: <8b5805ff0909121717w1516c273k2a568779b9c31662@mail.gmail.com>
Subject: Re: [PATCH] libata: Add pata_atp867x driver for Artop/Acard ATP867X 
	controllers
To: Robert Hancock <hancockrwd@gmail.com>
Cc: Daniel Walker <dwalker@fifo99.com>, Jeff Garzik <jgarzik@pobox.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>
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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.

Thanks,
-John
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