[PATCH v4 1/2] bus: mhi: Fix pm_state conversion to string

From: Paul Davey
Date: Wed Aug 11 2021 - 23:17:49 EST


On big endian architectures the mhi debugfs files which report pm state
give "Invalid State" for all states. This is caused by using
find_last_bit which takes an unsigned long* while the state is passed in
as an enum mhi_pm_state which will be of int size.

Fix by using __fls to pass the value of state instead of find_last_bit.

Fixes: a6e2e3522f29 ("bus: mhi: core: Add support for PM state transitions")
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Manivannan Sadhasivam <mani@xxxxxxxxxx>
Reviewed-by: Hemant Kumar <hemantk@xxxxxxxxxxxxxx>
Signed-off-by: Paul Davey <paul.davey@xxxxxxxxxxxxxxxxxxx>
---
drivers/bus/mhi/core/init.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index 5aaca6d0f52b..0d588b60929e 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -79,9 +79,12 @@ static const char * const mhi_pm_state_str[] = {

const char *to_mhi_pm_state_str(enum mhi_pm_state state)
{
- int index = find_last_bit((unsigned long *)&state, 32);
+ int index;

- if (index >= ARRAY_SIZE(mhi_pm_state_str))
+ if (state)
+ index = __fls(state);
+
+ if (!state || index >= ARRAY_SIZE(mhi_pm_state_str))
return "Invalid State";

return mhi_pm_state_str[index];
--
2.32.0