| From | Guenter Roeck <> | Date | Tue, 10 Dec 2019 13:32:15 -0800 | Subject | Re: [PATCH AUTOSEL 5.4 277/350] tpm: Add a flag to indicate TPM power is managed by firmware |
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On Tue, Dec 10, 2019 at 1:12 PM Sasha Levin <sashal@kernel.org> wrote: > > From: Stephen Boyd <swboyd@chromium.org> > > [ Upstream commit 2e2ee5a2db06c4b81315514b01d06fe5644342e9 ] > > On some platforms, the TPM power is managed by firmware and therefore we > don't need to stop the TPM on suspend when going to a light version of > suspend such as S0ix ("freeze" suspend state). Add a chip flag, > TPM_CHIP_FLAG_FIRMWARE_POWER_MANAGED, to indicate this so that certain > platforms can probe for the usage of this light suspend and avoid > touching the TPM state across suspend/resume. >
Are the patches needed to support CR50 (which need this patch) going to be applied to v5.4.y as well ? If not, what is the purpose of applying this patch to v5.4.y ?
Thanks, Guenter
> Cc: Andrey Pronin <apronin@chromium.org> > Cc: Duncan Laurie <dlaurie@chromium.org> > Cc: Jason Gunthorpe <jgg@ziepe.ca> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: Guenter Roeck <groeck@chromium.org> > Cc: Alexander Steffen <Alexander.Steffen@infineon.com> > Cc: Heiko Stuebner <heiko@sntech.de> > Tested-by: Heiko Stuebner <heiko@sntech.de> > Reviewed-by: Heiko Stuebner <heiko@sntech.de> > Signed-off-by: Stephen Boyd <swboyd@chromium.org> > Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> > Signed-off-by: Sasha Levin <sashal@kernel.org> > --- > drivers/char/tpm/tpm-interface.c | 8 +++++++- > drivers/char/tpm/tpm.h | 1 + > 2 files changed, 8 insertions(+), 1 deletion(-) > > diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c > index d7a3888ad80f0..7f105490604c8 100644 > --- a/drivers/char/tpm/tpm-interface.c > +++ b/drivers/char/tpm/tpm-interface.c > @@ -23,6 +23,7 @@ > #include <linux/slab.h> > #include <linux/mutex.h> > #include <linux/spinlock.h> > +#include <linux/suspend.h> > #include <linux/freezer.h> > #include <linux/tpm_eventlog.h> > > @@ -394,7 +395,11 @@ int tpm_pm_suspend(struct device *dev) > return -ENODEV; > > if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED) > - return 0; > + goto suspended; > + > + if ((chip->flags & TPM_CHIP_FLAG_FIRMWARE_POWER_MANAGED) && > + !pm_suspend_via_firmware()) > + goto suspended; > > if (!tpm_chip_start(chip)) { > if (chip->flags & TPM_CHIP_FLAG_TPM2) > @@ -405,6 +410,7 @@ int tpm_pm_suspend(struct device *dev) > tpm_chip_stop(chip); > } > > +suspended: > return rc; > } > EXPORT_SYMBOL_GPL(tpm_pm_suspend); > diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h > index a7fea3e0ca86a..f3bf2f7f755c8 100644 > --- a/drivers/char/tpm/tpm.h > +++ b/drivers/char/tpm/tpm.h > @@ -162,6 +162,7 @@ enum tpm_chip_flags { > TPM_CHIP_FLAG_VIRTUAL = BIT(3), > TPM_CHIP_FLAG_HAVE_TIMEOUTS = BIT(4), > TPM_CHIP_FLAG_ALWAYS_POWERED = BIT(5), > + TPM_CHIP_FLAG_FIRMWARE_POWER_MANAGED = BIT(6), > }; > > #define to_tpm_chip(d) container_of(d, struct tpm_chip, dev) > -- > 2.20.1 >
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