Put runtime PM to resume state between suspend() and suspend_noirq(),
resume_noirq() and resume(), because some I2C devices need the controller
on to perform communication during this period.
The controller can't be woken up once runtime pm is disabled and in
runtime autosuspended state.
The problem can be easily reproduced on the I.MX8MQ platform:
the PMIC needs to be used to enable regulator when the system resumes.
When the PMIC uses the I2C controller, I2C runtime pm has not been enabled,
so in i2c xfer(), pm_runtime_resume_and_get() will return an error,
which causes data transfer to fail. Therefore, regulators cannot
be enabled and system resume hangs.
Here is resume error log:
[ 53.888902] galcore 38000000.gpu3d: PM: calling genpd_resume_noirq @ 529, parent: platform
[ 53.897203] i2c_imx_xfer, pm_runtime_resume_and_get is -13
[ 53.902713] imx-pgc imx-pgc-domain.5: failed to enable regulator: -EACCES
[ 53.909518] galcore 38000000.gpu3d: PM: genpd_resume_noirq returned 0 after 12331 usecs
[ 53.917545] mxc_hantro 38300000.vpu: PM: calling genpd_resume_noirq @ 529, parent: soc@0
[ 53.925659] i2c_imx_xfer, pm_runtime_resume_and_get is -13
[ 53.931157] imx-pgc imx-pgc-domain.6: failed to enable regulator: -EACCES
I.MX8MQ system resume normally after applying the fix. Here is resume log:
[ 71.068807] galcore 38000000.gpu3d: PM: calling genpd_resume_noirq @ 530, parent: platform
[ 71.077103] i2c_imx_xfer, pm_runtime_resume_and_get is 0
[ 71.083578] galcore 38000000.gpu3d: PM: genpd_resume_noirq returned 0 after 6490 usecs
[ 71.091526] mxc_hantro 38300000.vpu: PM: calling genpd_resume_noirq @ 530, parent: soc@0
[ 71.099638] i2c_imx_xfer, pm_runtime_resume_and_get is 0
[ 71.106091] mxc_hantro 38300000.vpu: PM: genpd_resume_noirq returned 0 after 6458 usecs
Signed-off-by: Carlos Song <carlos.song@nxp.com>
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20241125142108.1613016-1-carlos.song@nxp.com
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
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