On 1/25/22 10:38 AM, Jean Delvare wrote:
> On Tue, 25 Jan 2022 09:18:59 -0600, Terry Bowman wrote:
>> On 1/25/22 7:45 AM, Jean Delvare wrote:
>>> On Tue, 18 Jan 2022 14:22:32 -0600, Terry Bowman wrote:
>>>> +static int __sp5100_tco_prepare_base(struct sp5100_tco *tco,
>>>> + u32 mmio_addr,
>>>> + const char *dev_name)
>>>> +{
>>>> + struct device *dev = tco->wdd.parent;
>>>> + int ret = 0;
>>>> +
>>>> + if (!mmio_addr)
>>>> + return -ENOMEM;
>>>
>>> Can this actually happen? If it does, is -ENOMEM really the best error
>>> value?
>>
>> This can happen if mmio_addr is not assigned in sp5100_tco_setupdevice_mmio()
>> before calling sp5100_tco_prepare_base() and __sp5100_tco_prepare_base().
>
> Ah yes, I can see it now.
>
>> I can move the NULL check out of __sp5100_tco_prepare_base() and into
>> sp5100_tco_prepare_base() before calling __sp5100_tco_prepare_base().
>> As you describe below.
>>
>> The ENOMEM return value should be interpreted as the mmio_addr is not
>> available. EBUSY does not describe the failure correctly because EBUSY
>> implies the resource is present and normally available but not available
>> at this time. Do you have a return value preference ?
>
> Well, if one mmio_addr isn't set, you shouldn't call
> __sp5100_tco_prepare_base() for it so there's no error to return. If
> neither mmio_addr is set then the hardware is simply not configured to
> be used, so that would be a -NODEV returned by
> sp5100_tco_prepare_base() I suppose?
I agree, -NODEV communicates the error status better.
>
> BTW...
>
>>>> (...)
>>>> + if (ret)
>>>> + dev_err(dev, "Failed to reserve-map MMIO (%X) and alternate MMIO (%X) regions. ret=%X",
>>>> + mmio_addr, alt_mmio_addr, ret);
>
> ... I think that should be a "or" rather than "and", and singular
> "region", in this error message? I mean, the plan was never to
> reserve-map both of them, if I understand correctly.
>
This dev_err() is executed when both mmio_addr and alt_mmio_addr addresses failed either
devm_request_mem_region() or failed devm_ioremap(). I think the following would be most accurate:
dev_err(dev,
"Failed to reserve or map the MMIO (0x%X) and alternate MMIO (0x%X) regions, ret=%d",
mmio_addr, alt_mmio_addr, ret);
Above is my preference but I don't have a strong opinion. Providing the address and error code
information in the message is most important. I will make the change as you requested.
Regards,
Terry
