Runtime PM has to be enabled before creating the PHY, since phy_create()
only enables runtime PM on the PHY device if it is already enabled on
this parent device. This opens a small window where the device can be
runtime suspended after pm_runtime_enable() and before the later
pm_runtime_forbid(), causing an unnecessary suspend/resume cycle while
the PHY is not yet registered.
Take a runtime PM usage reference with pm_runtime_get_noresume() before
enabling runtime PM and release it once the PHY has been created to
prevent the device from being runtime suspended during that window.
This also makes the probe path safe independently of pm_runtime_forbid(),
which is a good preparation for potentially dropping the forbid() call in
the future and letting runtime PM be enabled by default.
Signed-off-by: Loic Poulain <loic.poulain@oss.qualcomm.com>
Link: https://patch.msgid.link/20260722-qcom-usb-phy-fix-null-v6-7-534f7e61b9a6@oss.qualcomm.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
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