On 11/16/2023 6:33 PM, Johan Hovold wrote:
On Wed, Nov 15, 2023 at 11:12:16PM +0530, Krishna Kurapati PSSNV wrote:
Are you sure there's no support for hs_phy_irq also in the "femto" PHYs
and that it's just that there is currently no driver support for using
them?
And why is it defined if there is truly no use for it?
We had an internal sync up with HW folks and here is some baseline
suggestions we received:
If DP/DM interrupts are defined, then that is the preferred path to
used, irrespective if HS Phy irq is defined or not / or whether it is
Femto / QUSB2 target. There is no target that has femto phy but misses
DP/DM today.
Ok, but just knowing that it is "preferred" does not in itself mean that
it should be removed from the binding.
We need to know that it's effectively useless (i.e. that the interrupts
are defined but cannot be triggered) for that.
We can still use the DP/DM interrupts in favour of HS in the driver
however.
For cases like sdm660/msm8998/msm8953/msm8956, these targets use
hs_phy_irq only and don't rely on DP/DM. So we cannot remove the binding
in entirety.
I fixed the binding for those specific platforms last year:
dd566faebe9f ("dt-bindings: usb: qcom,dwc3: refine interrupt requirements")
But as I mentioned in that commit message the following platforms do not
have any wakeup interrupts specified in mainline currently:
- qcom,ipq4019-dwc3
- qcom,ipq6018-dwc3
- qcom,ipq8064-dwc3
- qcom,ipq8074-dwc3
- qcom,msm8994-dwc3
- qcom,qcs404-dwc3
It would be good to get that cleaned up too (i.e. add the missing
interrupt definitions and update the binding to match).
Also, if hs_phy_irq and dp/dm_phy_irq were mutually exclusive, why does
the following Qualcomm SoCs define all three?
HS Phy Irq is redundant or functionality is mutually exclusive in this
case. If there are targets that define all three, then we need to update
those to only utilize DP/DM interrupts.
No, as I wrote above that depends on if the HS interrupt is truly
useless. Otherwise it still belongs in the binding, even if the driver
uses DP/DM in place of it.
Again, the binding should describe the hardware, not what a particular
OS chooses to use.
Hi Johan,
Sorry for delayed response.
Pushed [1] to address all the queries and comments. I was initially
looking at only Femto phy targets, but when I looked at all targets in
general, seems there is one irq not defined in bindings. It is qubs2_phy
irq which is named as "hs_phy_irq" on QUSB target DT's (both downstream
and upstream).
There is one actual "hs_phy_irq" as well but it is not used either by hs
validation team or sw team on any target. It was put in for debug
purpose only and doesn't have code to trigger it (even downstream never
implemented it I suppose) Atleast 4.4 onwards I saw the code but I
didn't see the actual hs_phy_irq being used. It was the qusb2_phy irq
named as hs_phy_irq.
Even hw folks used it under the same name which is why they recommended
using it on qusb2 targets and dp/dm on femto targets.
As we moved from qusb2 to femto phys, since qusb2_phy irq was not
present, the actual hs_phy_irq was put in the interrupts although it is
never triggered. That is why when I tried to check on sa8295-adp
multiport, those 4 hs interrupts never got fired. Hope the explanation
clears the confusion present around the interrupts.
On some targets the hs_phy_irq was given vector number of pwr_event irq
also like sm8550/sm8450 etc., I tried to address those as well in the
series.
Also, per your question as to there are some qusb2 targets having dp/dm
interrupts defined... It is only for SDM845/SDM670/SM6350 which were
last in line of using qusb2 phy's and they started incorporating dp/dm
interrupts.
Also added missing interrupts for qcs404/ipq5332.
I didn't add missing interrupts on sc8280xp because I see that current
interrupts present are working fine (I see ADB working and wakeup
working as well), but the interrupt vector numbers are off by "1"
between hs specifics and DT (both upstream and downstream). Will sort it
out and clean that target up later.
[1]: https://patchwork.kernel.org/project/linux-arm-msm/list/?series=803412
Regards,
Krishna,
