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diff --git a/doc/release-notes/skiboot-6.0.3.rst b/doc/release-notes/skiboot-6.0.3.rst new file mode 100644 index 0000000..3f127da --- /dev/null +++ b/doc/release-notes/skiboot-6.0.3.rst @@ -0,0 +1,53 @@ +.. _skiboot-6.0.3: + +============= +skiboot-6.0.3 +============= + +skiboot 6.0.3 was released on Wednesday May 23rd, 2018. It replaces +:ref:`skiboot-6.0.2` as the current stable release in the 6.0.x series. + +It is recommended that 6.0.3 be used instead of any previous 6.0.x version. + +Over :ref:`skiboot-6.0.3`, we have bug fixes related to i2c booting in +secure mode, and general functionality with a TPM present. These changes are: + +- p8-i2c: Remove force reset + + Force reset was added as an attempt to work around some issues with TPM + devices locking up their I2C bus. In that particular case the problem + was that the device would hold the SCL line down permanently due to a + device firmware bug. The force reset doesn't actually do anything to + alleviate the situation here, it just happens to reset the internal + master state enough to make the I2C driver appear to work until + something tries to access the bus again. + + On P9 systems with secure boot enabled there is the added problem + of the "diagostic mode" not being supported on I2C masters A,B,C and + D. Diagnostic mode allows the SCL and SDA lines to be driven directly + by software. Without this force reset is impossible to implement. + + This patch removes the force reset functionality entirely since: + + a) it doesn't do what it's supposed to, and + b) it's butt ugly code + + Additionally, turn p8_i2c_reset_engine() into p8_i2c_reset_port(). + There's no need to reset every port on a master in response to an + error that occurred on a specific port. + +- libstb/i2c-driver: Bump max timeout + + We have observed some TPMs clock streching the I2C bus for signifigant + amounts of time when processing commands. The same TPMs also have + errata that can result in permernantly locking up a bus in response to + an I2C transaction they don't understand. Using an excessively long + timeout to prevent this in the field. +- Add TPM timeout workaround + + Set the default timeout for any bus containing a TPM to one second. This + is needed to work around a bug in the firmware of certain TPMs that will + clock strech the I2C port the for up to a second. Additionally, when the + TPM is clock streching it responds to a STOP condition on the bus by + bricking itself. Clearing this error requires a hard power cycle of the + system since the TPM is powered by standby power. |