Change in coreboot[master]: drivers/spi/tpm: Improve error checking

[Caveh Jalali (Code Review)]

Hello Jes Klinke, Vadim Bendebury, Christian Walter, Tim Wawrzynczak, Duncan Laurie,

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/45232

to look at the new patch set (#2).

Change subject: drivers/spi/tpm: Improve error checking
......................................................................

drivers/spi/tpm: Improve error checking

This adds error checking in paths that previously ignored TPM
communication errors. We hit this case occasionally during "Checking
cr50 for pending updates"; previously we would go down this path and
eventually time out using MAX_STATUS_TIMEOUT, which is 2 minutes.
Now, we detect the failure and return with an error indication instead
of timing out after a long time. The root cause of the communication
error is an open issue.

BUG=b:168090038
TEST=booted on volteer, observed error handling when
    "Checking cr50 for pending updates" fails.

Signed-off-by: Caveh Jalali 
Change-Id: Ia8a1202000abce1857ee694b06b1478e6b045069
---
M src/drivers/spi/tpm/tpm.c
1 file changed, 38 insertions(+), 17 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/32/45232/2