[PATCH] pmdomain: bcm: bcm2835-power: Fix broken reset status read

[Maíra Canal]

bcm2835_reset_status() has a misplaced parenthesis on every PM_READ()
call. Since PM_READ(reg) expands to readl(power->base + (reg)), the
expression:

    PM_READ(PM_GRAFX & PM_V3DRSTN)

computes the bitwise AND of the register offset PM_GRAFX with the
bitmask PM_V3DRSTN before using the result as a register offset, reading
from the wrong MMIO address instead of the intended PM_GRAFX register.
The same issue affects the PM_IMAGE cases.

Fix by moving the closing parenthesis so PM_READ() receives only the
register offset, and the bitmask is applied to the value returned by
the read.

Fixes: 670c672608a1 ("soc: bcm: bcm2835-pm: Add support for power domains under a new binding.")
Signed-off-by: Maíra Canal <mcanal at igalia.com>
---

Hi,

Most likely this bug went unnoticed as there is no in-tree driver
currently calling reset_control_status() on the BCM2835 reset
controller. Although I'm sending a fix to the .status callback, another
possibility would be removing the implementation of this callback
considering that (1) it's broken and (2) it's not used.

I'd appreciate your feedback about the most suitable option.

Best regards,
- Maíra

---

 drivers/pmdomain/bcm/bcm2835-power.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/pmdomain/bcm/bcm2835-power.c b/drivers/pmdomain/bcm/bcm2835-power.c
index 1d29addfe036..0450202bbee2 100644
--- a/drivers/pmdomain/bcm/bcm2835-power.c
+++ b/drivers/pmdomain/bcm/bcm2835-power.c
@@ -580,11 +580,11 @@ static int bcm2835_reset_status(struct reset_controller_dev *rcdev,
 
 	switch (id) {
 	case BCM2835_RESET_V3D:
-		return !PM_READ(PM_GRAFX & PM_V3DRSTN);
+		return !(PM_READ(PM_GRAFX) & PM_V3DRSTN);
 	case BCM2835_RESET_H264:
-		return !PM_READ(PM_IMAGE & PM_H264RSTN);
+		return !(PM_READ(PM_IMAGE) & PM_H264RSTN);
 	case BCM2835_RESET_ISP:
-		return !PM_READ(PM_IMAGE & PM_ISPRSTN);
+		return !(PM_READ(PM_IMAGE) & PM_ISPRSTN);
 	default:
 		return -EINVAL;
 	}
-- 
2.52.0