Identified resume-probe race condition in kernel v7.0 with the commit
38fa29b01a ("i2c: designware: Combine the init functions"),but this
issue existed from the beginning though not detected.
The amdisp i2c device requires ISP to be in power-on state for probe
to succeed. To meet this requirement, this device is added to genpd
to control ISP power using runtime PM. The pm_runtime_get_sync() called
before i2c_dw_probe() triggers PM resume, which powers on ISP and also
invokes the amdisp i2c runtime resume before the probe completes resulting
in this race condition and a NULL dereferencing issue in v7.0
Fix this race condition by using the genpd APIs directly during probe:
- Call dev_pm_genpd_resume() to Power ON ISP before probe
- Call dev_pm_genpd_suspend() to Power OFF ISP after probe
- Set the device to suspended state with pm_runtime_set_suspended()
- Enable runtime PM only after the device is fully initialized
Fixes: d6263c468a ("i2c: amd-isp: Add ISP i2c-designware driver")
Co-developed-by: Bin Du <bin.du@amd.com>
Signed-off-by: Bin Du <bin.du@amd.com>
Signed-off-by: Pratap Nirujogi <pratap.nirujogi@amd.com>
Cc: <stable@vger.kernel.org> # v6.16+
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20260320201302.3490570-1-pratap.nirujogi@amd.com
e2f1ada8e0