[PATCH for-linus-v5.5-rc6 3/3] tpm: Revert "tpm_tis_core: Turn on the TPM before probing IRQ's"

[Jarkko Sakkinen]

From: Stefan Berger <stefanb@xxxxxxxxxxxxx>

There has been a bunch of reports (one from kernel bugzilla linked)
reporting that when this commit is applied it causes on some machines
boot freezes.

Unfortunately hardware where this commit causes a failure is not widely
available (only one I'm aware is Lenovo T490), which means we cannot
predict yet how long it will take to properly fix tpm_tis interrupt
probing.

Thus, the least worst short term action is to revert the code to the
state before this commit. In long term we need fix the tpm_tis probing
code to work on machines that Stefan's fix was supposed to fix.

Fixes: 21df4a8b6018 ("tpm_tis: reserve chip for duration of tpm_tis_core_init")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=205935
Cc: stable@xxxxxxxxxxxxxxx
Cc: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Tested-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Tested-by: Xiaoping Zhou <xiaoping.zhou@xxxxxxxxx>
Signed-off-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>
Reported-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
---
 drivers/char/tpm/tpm_tis_core.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 5dc52c4e2292..27c6ca031e23 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -1059,7 +1059,6 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 			goto out_err;
 		}
 
-		tpm_chip_start(chip);
 		if (irq) {
 			tpm_tis_probe_irq_single(chip, intmask, IRQF_SHARED,
 						 irq);
@@ -1069,7 +1068,6 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 		} else {
 			tpm_tis_probe_irq(chip, intmask);
 		}
-		tpm_chip_stop(chip);
 	}
 
 	rc = tpm_chip_register(chip);
-- 
2.20.1