| Message ID | 20190806220750.86597-2-swboyd@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | tpm: Add driver for cr50 | expand |
On Tue, 2019-08-06 at 15:07 -0700, Stephen Boyd wrote: > 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 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. The commit message should mention the new constant. > + if (chip->flags & TPM_CHIP_FLAG_FIRMWARE_POWER_MANAGED) > + if (!pm_suspend_via_firmware()) Why both checks are needed? If both checks are needed, you could write it as a single conditional statement: if (chip->flags & TPM_CHIP_FLAG_FIRMWARE_POWER_MANAGED && !pm_suspend_via_firmware()) /Jarkko
Quoting Jarkko Sakkinen (2019-08-09 11:02:01) > On Tue, 2019-08-06 at 15:07 -0700, Stephen Boyd wrote: > > 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 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. > > The commit message should mention the new constant. Alright. > > > + if (chip->flags & TPM_CHIP_FLAG_FIRMWARE_POWER_MANAGED) > > + if (!pm_suspend_via_firmware()) > > Why both checks are needed? > > If both checks are needed, you could write it as a single > conditional statement: > > if (chip->flags & TPM_CHIP_FLAG_FIRMWARE_POWER_MANAGED && > !pm_suspend_via_firmware()) > Ok. I'll combine them.
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index 1b4f95c13e00..9bf3ddee6c8c 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> @@ -395,7 +396,11 @@ 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) + if (!pm_suspend_via_firmware()) + goto suspended; if (!tpm_chip_start(chip)) { if (chip->flags & TPM_CHIP_FLAG_TPM2) @@ -406,6 +411,7 @@ 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 e503ffc3aa39..28f73331aa2e 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)
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 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. 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> Signed-off-by: Stephen Boyd <swboyd@chromium.org> --- drivers/char/tpm/tpm-interface.c | 8 +++++++- drivers/char/tpm/tpm.h | 1 + 2 files changed, 8 insertions(+), 1 deletion(-)