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Manivannan Sadhasivam
310a8cc746
[ Upstream commitd922113ef9] 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, store the error pointer in a global xarray with ice node phandle as a key during probe in addition to the valid ice pointer and synchronize both qcom_ice_probe() and of_qcom_ice_get() using a mutex. If the xarray entry is NULL, then it implies that the driver is not probed yet, so return -EPROBE_DEFER. If it has any error pointer, return that error pointer directly. Otherwise, add the devlink as usual and return the valid pointer to the consumer. Xarray is used instead of platform drvdata, since driver core frees the drvdata during probe failure. So it cannot be used to pass the error pointer to the consumers. 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. Fixes:2afbf43a4a("soc: qcom: Make the Qualcomm UFS/SDCC ICE a dedicated driver") Reported-by: Sumit Garg <sumit.garg@oss.qualcomm.com> Tested-by: Sumit Garg <sumit.garg@oss.qualcomm.com> # OP-TEE as TZ Acked-by: Sumit Garg <sumit.garg@oss.qualcomm.com> Cc: stable@vger.kernel.org # 6.4 Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com> Link: https://lore.kernel.org/r/20260518-qcom-ice-fix-v7-1-2a595382185b@oss.qualcomm.com Signed-off-by: Bjorn Andersson <andersson@kernel.org> [ changed `.remove` to `.remove_new` for the void callback and replaced the `__free(device_node)` direct-return with an explicit `goto out` in `of_qcom_ice_get()` ] Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.