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| author | Evan Green <evgreen@chromium.org> | 2019-06-27 22:44:45 +0200 |
|---|---|---|
| committer | Enric Balletbo i Serra <enric.balletbo@collabora.com> | 2019-07-01 15:39:11 +0200 |
| commit | 8c3166e17cf10161d2871dfb1d017287c7b79ff1 (patch) | |
| tree | d5a236fb41c68187aac195ba0c4033bd8a428713 /Documentation | |
| parent | platform/chrome: lightbar: Get drvdata from parent in suspend/resume (diff) | |
| download | linux-8c3166e17cf10161d2871dfb1d017287c7b79ff1.tar.xz linux-8c3166e17cf10161d2871dfb1d017287c7b79ff1.zip | |
mfd / platform: cros_ec_debugfs: Expose resume result via debugfs
For ECs that support it, the EC returns the number of slp_s0
transitions and whether or not there was a timeout in the resume
response. Expose the last resume result to usermode via debugfs so
that usermode can detect and report S0ix timeouts.
Signed-off-by: Evan Green <evgreen@chromium.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/testing/debugfs-cros-ec | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/debugfs-cros-ec b/Documentation/ABI/testing/debugfs-cros-ec index 573a82d23c89..1fe0add99a2a 100644 --- a/Documentation/ABI/testing/debugfs-cros-ec +++ b/Documentation/ABI/testing/debugfs-cros-ec @@ -32,3 +32,25 @@ Description: is used for synchronizing the AP host time with the EC log. An error is returned if the command is not supported by the EC or there is a communication problem. + +What: /sys/kernel/debug/<cros-ec-device>/last_resume_result +Date: June 2019 +KernelVersion: 5.3 +Description: + Some ECs have a feature where they will track transitions to + the (Intel) processor's SLP_S0 line, in order to detect cases + where a system failed to go into S0ix. When the system resumes, + an EC with this feature will return a summary of SLP_S0 + transitions that occurred. The last_resume_result file returns + the most recent response from the AP's resume message to the EC. + + The bottom 31 bits contain a count of the number of SLP_S0 + transitions that occurred since the suspend message was + received. Bit 31 is set if the EC attempted to wake the + system due to a timeout when watching for SLP_S0 transitions. + Callers can use this to detect a wake from the EC due to + S0ix timeouts. The result will be zero if no suspend + transitions have been attempted, or the EC does not support + this feature. + + Output will be in the format: "0x%08x\n". |