[Skiboot] [PATCH v2 2/5] hdata/i2c: ignore i2c devs marked as unknown in the hdat

[Claudio Carvalho]

On 20/09/2017 02:44, Stewart Smith wrote:
> Claudio Carvalho <cclaudio at linux.vnet.ibm.com> writes:
>> On 01/09/2017 01:03, Oliver wrote:
>>> On Thu, Aug 31, 2017 at 5:12 PM, Claudio Carvalho
>>> <cclaudio at linux.vnet.ibm.com> wrote:
>>>> Some I2C devices are marked as unknown in the hdat. We don't need to add
>>>> them to the device tree, so this just log them.
>>>>
>>>> Signed-off-by: Claudio Carvalho <cclaudio at linux.vnet.ibm.com>
>>>> ---
>>>>    hdata/i2c.c | 11 +++++++++++
>>>>    1 file changed, 11 insertions(+)
>>>>
>>>> diff --git a/hdata/i2c.c b/hdata/i2c.c
>>>> index cc127d5..bfb5b48 100644
>>>> --- a/hdata/i2c.c
>>>> +++ b/hdata/i2c.c
>>>> @@ -226,6 +226,17 @@ int parse_i2c_devs(const struct HDIF_common_hdr *hdr, int idata_index,
>>>>                    */
>>>>                   i2c_addr = dev->i2c_addr >> 1;
>>>>
>>>> +               /*
>>>> +                * Some i2c devs are marked as unknown in the hdat.
>>>> +                * Ignoring them.
>>>> +                */
>>>> +               if (dev->type == 0xFF) {
>>>> +                       prlog(PR_INFO, "HDAT I2C: ignoring e%dp%d - unknown@%x "
>>>> +                             "(port 0x%x)\n", dev->i2cm_engine,
>>>> +                             dev->i2cm_port, i2c_addr, dev->i2c_port);
>>>> +                       continue;
>>>> +               }
>>>> +
>>> I kept these in the device-tree since I figured that we would want to
>>> know about them even if we don't know what they are. I don't have any
>>> strong opinions about it though so just logging it is fine with me.
>> I also don't have any strong opinion about that. I proposed this patch
>> because I don't know if an unknown i2c device like that could cause any
>> problem in the kernel. Probably it would be better to keep them in the
>> device tree even if firmware knows nothing about them.
>>
>> I will drop this patch
> I don't think we're in a great position to bet on what is and isn't good
> in the HDAT and we'll likely only learn by seeing what's in it and what
> happens rather than theorising.
>
> What I might do is take the patch but just have it PR_WARNING out while
> still adding the device and just see what shows up for a while.

Yeah, sounds good. I will update the patch.

Thanks,

Claudio