Attention is currently required from: Patrick Rudolph, Paul Menzel, Christian Walter, Arthur Heymans, Werner Zeh, Kyösti Mälkki.
Angel Pons has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/58240 )
Change subject: drivers/pc80/tpm: Use stopwatch for timeout-loops
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Patch Set 1:
(1 comment)
File src/drivers/pc80/tpm/tis.c:
https://review.coreboot.org/c/coreboot/+/58240/comment/bc83b317_69687d02
PS1, Line 257: udelay(1); /* 1 us */
I guess this is not harmfull since there is no restriction in the TPM how often the register can be […]
Polling too fast is an issue when reading the value interrupts the task one is waiting to be done. For example, when waiting for a laptop EC to finish doing something, if reading the corresponding status register triggers an interrupt handler in the EC, polling too fast can slow down the EC's normal operation and unnecessarily lengthen the wait. Something similar could happen with the ME or any other chip with its own processor. I don't know for sure, but I think this might also be the case for TPMs.
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