[U-Boot] [PATCH v3] dm: core: Enable optional use of fdt_translate_address()

[Bin Meng]

Hi Stefan,

On Thu, Dec 3, 2015 at 10:12 PM, Stefan Roese <sr at denx.de> wrote:
> Hi Bin,
>
>
> On 03.12.2015 14:34, Bin Meng wrote:
>>
>> Hi Stefan, Simon,
>>
>> On Mon, Oct 19, 2015 at 7:16 AM, Simon Glass <sjg at chromium.org> wrote:
>>>
>>> On 29 September 2015 at 23:00, Stefan Roese <sr at denx.de> wrote:
>>>>
>>>> The current "simple" address translation simple_bus_translate() is not
>>>> working on some platforms (e.g. MVEBU). As here more complex "ranges"
>>>> properties are used in many nodes (multiple tuples etc). This patch
>>>> enables the optional use of the common fdt_translate_address() function
>>>> which handles this translation correctly.
>>>>
>>>> Signed-off-by: Stefan Roese <sr at denx.de>
>>>> Cc: Simon Glass <sjg at chromium.org>
>>>> Cc: Bin Meng <bmeng.cn at gmail.com>
>>>> Cc: Marek Vasut <marex at denx.de>
>>>> Cc: Masahiro Yamada <yamada.masahiro at socionext.com>
>>>> Cc: Stephen Warren <swarren at nvidia.com>
>>>> Cc: Lukasz Majewski <l.majewski at samsung.com>
>>>> ---
>>>> v3:
>>>> - Rebased on current U-Boot version
>>>> - Added Stephen and Lukasz to Cc
>>>>
>>>> v2:
>>>> - Rework code a bit as suggested by Simon. Also added some comments
>>>>    to make the use of the code paths more clear.
>>>>
>>>>   drivers/core/Kconfig  | 30 ++++++++++++++++++++++++++++++
>>>>   drivers/core/device.c | 20 ++++++++++++++++++++
>>>>   2 files changed, 50 insertions(+)
>>>
>>>
>>> Applied to u-boot-dm, thanks!
>>
>>
>> When testing Simon's patch [1], I found PCI UART on Intel Crown Bay no
>> longer works. git bisect leads to this commit. Somehow I missed this
>> patch before although I see the commit message get me cc'ed but the
>> email did not bring to my attention.
>>
>> I see this patch introduced OF_TRANSLATE and by default set it to y.
>> This makes the code logic in dev_get_addr() go through
>> fdt_translate_address(), which breaks the things.
>
>
> I'm a bit surprised that using the common fdt_translate_address()
> function instead of the DM internal simple_bus_translate() causes
> problems on your platform. Are you sure that the ranges are
> described correctly in your dts? Is the dts a copy from the Linux
> original one? Ah, probably not, since we're talking about x86
> which has no DT support in Linux, right?
>

Is fdt_translate_address() able to handle PCI bus ranges property? PCI
has special ranges.

The arch/x86/dts/crownbay.dts has something like below:

 90         pci {
 91                 #address-cells = <3>;
 92                 #size-cells = <2>;
 93                 compatible = "pci-x86";
 94                 u-boot,dm-pre-reloc;
 95                 ranges = <0x02000000 0x0 0x40000000 0x40000000 0 0x80000000
 96                           0x42000000 0x0 0xc0000000 0xc0000000 0 0x20000000
 97                           0x01000000 0x0 0x2000 0x2000 0 0xe000>;
 98
 99                 pcie at 17,0 {
100                         #address-cells = <3>;
101                         #size-cells = <2>;
102                         compatible = "pci-bridge";
103                         u-boot,dm-pre-reloc;
104                         reg = <0x0000b800 0x0 0x0 0x0 0x0>;

>> Should we set
>> OF_TRANSLATE to n by default? If set to y, this requires dts to have
>> complete ranges property everywhere.
>
>
> My understanding here is that x86 is a special case. As it doesn't
> use the full-blown dts sources from Linux. But most likely some
> "simple" ones, written exactly for U-Boot / DM.
>
> I would still prefer to have this OF_TRANSLATE set to y as default.
> As its needed for at least some platforms. But if we decide to
> set it to n, I can live with it as well.
>

Regards,
Bin