Re: [PATCH v3 1/4] soc: qcom: ice: Fix race between qcom_ice_probe() and of_qcom_ice_get()

[Manivannan Sadhasivam]

+ Neeraj

On Mon, Feb 23, 2026 at 02:35:04PM -0600, Bjorn Andersson wrote:
> On Mon, Feb 23, 2026 at 01:32:52PM +0530, Manivannan Sadhasivam via B4 Relay wrote:
> > From: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxxxxxxxx>
> > 
> > The current platform driver design causes probe ordering races with
> > consumers (UFS, eMMC) due to ICE's dependency on SCM firmware calls. If ICE
> > probe fails (missing ICE SCM or DT registers), devm_of_qcom_ice_get() loops
> > with -EPROBE_DEFER, leaving consumers non-functional even when ICE should
> > be gracefully disabled. devm_of_qcom_ice_get() doesn't know if the ICE
> > driver probe has failed due to above reasons or it is waiting for the SCM
> > driver.
> > 
> > Moreover, there is no devlink dependency between ICE and consumer drivers
> > as 'qcom,ice' is not considered as a DT 'supplier'. So the consumer drivers
> > have no idea of when the ICE driver is going to probe.
> > 
> > To address these issues, introduce a global ice_handle to store the valid
> > ICE handle pointer, and set during successful ICE driver probe. On probe
> > failure, set it to an error pointer and propagate the error from
> > of_qcom_ice_get().
> > 
> > Additionally, add a global ice_mutex to synchronize qcom_ice_probe() and
> > of_qcom_ice_get().
> > 
> > Note that this change only fixes the standalone ICE DT node bindings and
> > not the ones with 'ice' range embedded in the consumer nodes, where there
> > is no issue.
> > 
> > Cc: <stable@xxxxxxxxxxxxxxx> # 6.4
> > Fixes: 2afbf43a4aec ("soc: qcom: Make the Qualcomm UFS/SDCC ICE a dedicated driver")
> > Reported-by: Sumit Garg <sumit.garg@xxxxxxxxxxxxxxxx>
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxxxxxxxx>
> > ---
> >  drivers/soc/qcom/ice.c | 44 +++++++++++++++++++++++++++-----------------
> >  1 file changed, 27 insertions(+), 17 deletions(-)
> > 
> > diff --git a/drivers/soc/qcom/ice.c b/drivers/soc/qcom/ice.c
> > index b203bc685cad..3c3c189e24f9 100644
> > --- a/drivers/soc/qcom/ice.c
> > +++ b/drivers/soc/qcom/ice.c
> > @@ -113,6 +113,9 @@ struct qcom_ice {
> >  	u8 hwkm_version;
> >  };
> >  
> > +static DEFINE_MUTEX(ice_mutex);
> > +static struct qcom_ice *ice_handle;
> 
> Did we get confirmation that in the UFS + SDCC case, there's only a
> single ICE instance per SoC?
> 

Right now there is only a single instance per SoC. But Neeraj told me that
upcoming SoCs are going to have multiple instances. But I don't want to spend
too much time on *upcoming* support, but rather fix the current
implementations.

Extending this to multiple instances would just require storing the ice_handle
with node name/address pair in xarray or in some other data structures.

- Mani

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