Change in coreboot[master]: soc/amd/common/block/espi_util: Workaround in-band reset race condition

[Raul Rangel (Code Review)]

Attention is currently required from: Jason Glenesk, Raul Rangel, Rob Barnes, Felix Held.
Hello build bot (Jenkins), Jason Glenesk, Furquan Shaikh, Marshall Dawson, Rob Barnes, Felix Held,

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

https://review.coreboot.org/c/coreboot/+/54070

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

Change subject: soc/amd/common/block/espi_util: Workaround in-band reset race condition
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soc/amd/common/block/espi_util: Workaround in-band reset race condition

When performing an in-band reset the host controller and the
peripheral can have mismatched IO configs.

i.e., The eSPI peripheral can be in IO-4 mode while, the
eSPI host will be in IO-1. This results in the peripheral
getting invalid packets and thus not responding.

If the peripheral is alerting when we perform an in-band
reset, there is a race condition in espi_send_command.
1) espi_send_command clears the interrupt status.
2) eSPI host controller hardware notices the alert and sends
   a GET_STATUS.
3) espi_send_command writes the in-band reset command.
4) eSPI hardware enqueues the in-band reset until GET_STATUS
   is complete.
5) GET_STATUS fails with NO_RESPONSE and sets the interrupt
   status.
6) eSPI hardware performs in-band reset.
7) espi_send_command checks the status and sees a
   NO_RESPONSE bit.

As a workaround we allow the NO_RESPONSE status code when
we perform an in-band reset.

BUG=b:186135022
TEST=suspend_stress_test and S5->S0 tests on guybrush. Verified S3
suspend and S5->S0 on zork.

Signed-off-by: Raul E Rangel 
Change-Id: I71271377f20eaf29032214be98794e1645d9b70a
---
M src/soc/amd/common/block/lpc/espi_util.c
1 file changed, 31 insertions(+), 2 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/70/54070/2