Hello,
Le 22/01/2024 à 18:30, Mark Brown a écrit :
> On Mon, Jan 22, 2024 at 06:04:42PM +0100, Romain Naour wrote:
>
>> We can't use devm_platform_ioremap_resource_byname() to remap the
>> interrupt register that can be shared between
>> regulator-abb-{ivahd,dspeve,gpu} drivers instance.
>
> ...
>
>> The commit b36c6b1887ff (regulator: ti-abb: Make use of the helper
>> function devm_ioremap related) overlooked the following comment
>> explaining why devm_ioremap() is used in this case:
>
>> /*
>> * We may have shared interrupt register offsets which are
>> * write-1-to-clear between domains ensuring exclusivity.
>> */
>
> I have to say that I wouldn't infer from that comment that there is any
> reason why _byname() won't work - one would generally expect that a
> get_resource_by_name() followed by an ioremap() of that resource would
> be equivalent to the combined helper. Based on the commit log here I
> frankly have no idea what the issue is. You should also add something
> to the code which makes it clear what the issue is so the same
> conversion isn't performed again, assuming that the fix isn't in the
> helper.
I'm agree with you about the existing comment that is not really crystal clear.
The combined helper introduce a call to devm_request_mem_region() that create a
new busy resource region on PRM_IRQSTATUS_MPU register (0x4ae06010). The first
devm_request_mem_region() call succeed for regulator-abb-ivahd but fail for the
two other regulator-abb-dspeve and regulator-abb-gpu.
Here is the iomem content without this patch:
# cat /proc/iomem | grep -i 4ae06
4ae06010-4ae06013 : 4ae07e34.regulator-abb-ivahd int-address
4ae06014-4ae06017 : 4ae07ddc.regulator-abb-mpu int-address
regulator-abb-dspeve and regulator-abb-gpu are missing due to
devm_request_mem_region() failure (EBUSY)
I don't know how to fix this issue keeping
devm_platform_ioremap_resource_byname() when the same address is used several
time... suggestion welcome.
>
>>
>> Fixes:
>
> You're missing the commit here.
>
>> This partially reverts commit b36c6b1887ffc6b58b556120bfbd511880515247.
>
> Please include human readable descriptions of things like commits and
> issues being discussed in e-mail in your mails, this makes them much
> easier for humans to read especially when they have no internet access.
> I do frequently catch up on my mail on flights or while otherwise
> travelling so this is even more pressing for me than just being about
> making things a bit easier to read.
I added such human description above in the commit log but forgot to update this
one, sorry.
Thank you for the review.
Best regards,
Romain
