[PATCH 1/2] OMAP2+: IOMMU: change OMAP2+ error message to dev_dbg()

[David Cohen]

On Tue, Feb 15, 2011 at 3:59 PM, Jarkko Nikula <jhnikula at gmail.com> wrote:
> On Tue, 15 Feb 2011 15:44:27 +0200
> David Cohen <dacohen at gmail.com> wrote:
>
>> >> @@ -163,13 +163,13 @@ static u32 omap2_iommu_fault_isr(struct iommu *obj,
>> >> u32 *ra)
>> >>        da = iommu_read_reg(obj, MMU_FAULT_AD);
>> >>        *ra = da;
>> >>
>> >> -       dev_err(obj->dev, "%s:\tda:%08x ", __func__, da);
>> >> +       dev_dbg(obj->dev, "%s:\tda:%08x ", __func__, da);
>> >
>> >   Note that dev_dbg() will only print something if either DEBUG or
>> > CONFIG_DYNAMIC_DEBUG are defined...
>>
>> That's my plan.
>>
> So it's sure that a developer won't need these error dumps when
> receiving an error report? I.e. IOMMU upper level errors give enough
> information to start doing own debugging?

Yes, developers do need this information.
But it's a bit useless tell only we've got an iommu fault, due to many
places might be causing it. My purpose is to let the debug
responsibility to IOMMU users. They have access to the iovmm layer as
well and can provide a much more useful information.
e.g. OMAP3 ISP has many submodules using IOMMU. With a fault callback,
it can dump all the iovm areas and the faulty 'da' too. It might
indicate which submodule was responsible for the issue.

Of course we can just let this debug messages the way they are and
print this redundant information. But IMO it's not necessary.

Regards,

David

>
> Just my 2 cents.
>
> --
> Jarkko
>