From: Jens Axboe <axboe@kernel.dk>
To: Stephen Douthit <stephend@silicom-usa.com>,
Christoph Hellwig <hch@infradead.org>
Cc: "linux-ide@vger.kernel.org" <linux-ide@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Dan Williams <dan.j.williams@intel.com>
Subject: Re: [PATCH] ata: ahci: Lookup PCS register offset based on PCI device ID
Date: Mon, 12 Aug 2019 08:11:22 -0600 [thread overview]
Message-ID: <679188f7-bb14-1de6-b533-687809fa7bc8@kernel.dk> (raw)
In-Reply-To: <abfa4b20-2916-d89a-f4d3-b27fca5906b2@silicom-usa.com>
On 8/12/19 6:02 AM, Stephen Douthit wrote:
> On 8/10/19 3:43 AM, Christoph Hellwig wrote:
>> On Thu, Aug 08, 2019 at 08:24:31PM +0000, Stephen Douthit wrote:
>>> Intel moved the PCS register from 0x92 to 0x94 on Denverton for some
>>> reason, so now we get to check the device ID before poking it on reset.
>>
>> And now you just match on the new IDs, which means we'll perpetually
>> catch up on any new device. Dan, can you reach out inside Intel to
>> figure out if there is a way to find out the PCS register location
>> without the PCI ID check?
>>
>>
>>> static int ahci_pci_reset_controller(struct ata_host *host)
>>> {
>>> struct pci_dev *pdev = to_pci_dev(host->dev);
>>> @@ -634,13 +669,14 @@ static int ahci_pci_reset_controller(struct ata_host *host)
>>>
>>> if (pdev->vendor == PCI_VENDOR_ID_INTEL) {
>>> struct ahci_host_priv *hpriv = host->private_data;
>>> + int pcs = ahci_pcs_offset(host);
>>> u16 tmp16;
>>>
>>> /* configure PCS */
>>> - pci_read_config_word(pdev, 0x92, &tmp16);
>>> + pci_read_config_word(pdev, pcs, &tmp16);
>>> if ((tmp16 & hpriv->port_map) != hpriv->port_map) {
>>> - tmp16 |= hpriv->port_map;
>>> - pci_write_config_word(pdev, 0x92, tmp16);
>>> + tmp16 |= hpriv->port_map & 0xff;
>>> + pci_write_config_word(pdev, pcs, tmp16);
>>> }
>>> }
>>
>> And Stephen, while you are at it, can you split this Intel-specific
>> quirk into a separate helper?
>
> I can do that. I'll wait until we hear back from Dan if there's a
> better scheme than a device ID lookup.
I'll drop the previous series for now.
--
Jens Axboe
next prev parent reply other threads:[~2019-08-12 14:11 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-08 20:24 [PATCH] ata: ahci: Lookup PCS register offset based on PCI device ID Stephen Douthit
2019-08-09 3:46 ` Jens Axboe
2019-08-09 14:13 ` Stephen Douthit
2019-08-09 14:16 ` Jens Axboe
2019-08-10 7:43 ` Christoph Hellwig
2019-08-10 20:22 ` Dan Williams
2019-08-12 13:02 ` Stephen Douthit
2019-08-12 14:11 ` Jens Axboe [this message]
2019-08-12 16:29 ` Dan Williams
2019-08-12 17:49 ` Stephen Douthit
2019-08-12 18:06 ` Christoph Hellwig
2019-08-12 19:12 ` Stephen Douthit
2019-08-12 19:31 ` Dan Williams
2019-08-13 7:29 ` Christoph Hellwig
2019-08-13 22:07 ` Dan Williams
2019-08-14 14:34 ` Stephen Douthit
2019-08-14 16:09 ` Dan Williams
2019-08-14 16:54 ` Stephen Douthit
2019-08-14 17:17 ` Dan Williams
2019-08-19 16:30 ` Stephen Douthit
2019-08-20 2:17 ` Dan Williams
2019-08-20 13:59 ` Stephen Douthit
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