linux-kernel - Re: [PATCH v2 1/5] phy: berlin-sata: Move PHY

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 24 Oct 2014 22:35:42 +0200
From:	Sebastian Hesselbarth <sebastian.hesselbarth@...il.com>
To:	balbi@...com
CC:	Kishon Vijay Abraham I <kishon@...com>,
	Antoine Ténart 
	<antoine.tenart@...e-electrons.com>, devicetree@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 1/5] phy: berlin-sata: Move PHY_BASE into private data
 struct

On 24.10.2014 22:25, Felipe Balbi wrote:
> Hi,
>
> On Fri, Oct 24, 2014 at 10:14:55PM +0200, Sebastian Hesselbarth wrote:
>> On 21.10.2014 11:40, Sebastian Hesselbarth wrote:
>>> On 10/21/2014 11:33 AM, Kishon Vijay Abraham I wrote:
>>>> On Tuesday 21 October 2014 02:37 PM, Sebastian Hesselbarth wrote:
>>>>> Currently, Berlin SATA PHY driver assumes PHY_BASE address being
>>>>> constant. While this PHY_BASE is correct for BG2Q, older BG2 PHY_BASE
>>>>> is different. Prepare the driver for BG2 support by moving the phy_base
>>>>> into private driver data.
>>>>>
>>>>> Acked-by: Antoine Ténart <antoine.tenart@...e-electrons.com>
>>>>> Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@...il.com>
>>> ...
>>>>> ---
>>>>>   drivers/phy/phy-berlin-sata.c | 42
>>>>> ++++++++++++++++++++++++++++--------------
>>>>>   1 file changed, 28 insertions(+), 14 deletions(-)
>>>>>
>>>>> diff --git a/drivers/phy/phy-berlin-sata.c
>>>>> b/drivers/phy/phy-berlin-sata.c
>>>>> index 69ced52d72aa..9682b0f66177 100644
>>>>> --- a/drivers/phy/phy-berlin-sata.c
>>>>> +++ b/drivers/phy/phy-berlin-sata.c
>>>>> @@ -30,7 +30,7 @@
>>>>>   #define MBUS_WRITE_REQUEST_SIZE_128    (BIT(2) << 16)
>>>>>   #define MBUS_READ_REQUEST_SIZE_128    (BIT(2) << 19)
>>>>>
>>>>> -#define PHY_BASE        0x200
>>>>> +#define BG2Q_PHY_BASE        0x200
>>> [...]
>>>>> +static u32 bg2q_sata_phy_base = BG2Q_PHY_BASE;
>>>>> +
>>>>> +static const struct of_device_id phy_berlin_sata_of_match[] = {
>>>>> +    {
>>>>> +        .compatible = "marvell,berlin2q-sata-phy",
>>>>> +        .data = &bg2q_sata_phy_base,
>>>>
>>>> Can't the base directly come from dt?
>>>
>>> You are suggesting a "marvell,phy-base-address" property, right?
>>> I have no strong opinion about it, I accept your call (or DT maintainer
>>> ones).
>>
>> Kishon,
>>
>> I still have the DT patches for BG2Q queued up for v3.19 (I missed the
>> arm-soc merge window for v3.18). That means, there has been no release
>> with the phy binding used and I can rework a little more.
>>
>> Can you please confirm that you want a DT property for the phy base address,
>> e.g. marvell,phy-base-address = <{0x200,0x80}> ?
>>
>> If so, I'd also rename the compatible from berlin2q-sata-phy to more
>> generic berlin-sata-phy.
>
> I think what Kishon is asking, is why this 0x200 offset isn't already on
> reg. so that instead of, e.g.:
>
> 	reg = <0x40000000 0x1000>;
>
> you would have:
>
> 	reg = <0x40000200 0x1000>;

Because it is the PHY_BASE offset within the _indirect_ register
access trough AHCI registers.

> then everybody's happy. It's unfortunate, however, that we already
> shipped DT sources with the bogus (?) reg property and now we have to
> support that broken binding. My suggestion would be to add a new
> compatible which comes with proper reg property and still add that weird
> phy_base for the old compatible, so that:

Nope, the reg property is correct and describes the (vendor-specific)
AHCI registers that are used for indirect access to PHY registers. When
writing to PHY registers, BG2 and BG2Q are different with respect to
the PHY_BASE address offset that has to be passed to indirect address
register.

> 	if (of_device_is_compatible(node, "marvell,berlin2q-sata-phy"))
> 		phy->phy_base = PHY_BASE;
>
> then, if new compatible comes with proper 'reg', phy->phy_base would be
> zero and everything should still work. How does this sound ?

The above is basically equivalent to the node match that I added with
this patch series. I can, of course, use above compatible match instead
of passing the phy_base in the of_device_id's .data.

Sebastian

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/