[PATCH] tpm/ppi: replace assertion code with recovery in tpm_eval_dsm

[Aditya Pakki]

In tpm_eval_dsm, BUG_ON on ppi_handle is used as an assertion.
By returning NULL to the callers, instead of crashing, the error
can be better handled.

Signed-off-by: Aditya Pakki <pakki001@xxxxxxx>
---
 drivers/char/tpm/tpm_ppi.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/char/tpm/tpm_ppi.c b/drivers/char/tpm/tpm_ppi.c
index b2dab941cb7f..4b6f6a9c0b48 100644
--- a/drivers/char/tpm/tpm_ppi.c
+++ b/drivers/char/tpm/tpm_ppi.c
@@ -42,7 +42,9 @@ static inline union acpi_object *
 tpm_eval_dsm(acpi_handle ppi_handle, int func, acpi_object_type type,
 	     union acpi_object *argv4, u64 rev)
 {
-	BUG_ON(!ppi_handle);
+	if (!ppi_handle)
+		return NULL;
+
 	return acpi_evaluate_dsm_typed(ppi_handle, &tpm_ppi_guid,
 				       rev, func, argv4, type);
 }
-- 
2.20.1