use of regmap_read() and regmap_write() in c_can_hw_raminit_syscon()
is not safe as the RAMINIT register can be shared between different drivers
at least for TI SoCs.
To make the modification atomic we switch to using regmap_update_bits().
Signed-off-by: Roger Quadros <rogerq@xxxxxx>
---
drivers/net/can/c_can/c_can_platform.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/net/can/c_can/c_can_platform.c b/drivers/net/can/c_can/c_can_platform.c
index f363972..364209a 100644
--- a/drivers/net/can/c_can/c_can_platform.c
+++ b/drivers/net/can/c_can/c_can_platform.c
@@ -110,6 +110,10 @@ static void c_can_hw_raminit_syscon(const struct c_can_priv *priv, bool enable)
*/
ctrl &= ~(1 << raminit->bits.start);
ctrl |= 1 << raminit->bits.done;
+
+ /* we can't use regmap_update_bits here as it will bypass the write
+ * if START is already 0 and DONE is already 1.
+ */
regmap_write(raminit->syscon, raminit->reg, ctrl);
ctrl &= ~(1 << raminit->bits.done);
@@ -118,12 +122,13 @@ static void c_can_hw_raminit_syscon(const struct c_can_priv *priv, bool enable)
if (enable) {
/* Set start bit and wait for the done bit. */
ctrl |= 1 << raminit->bits.start;
- regmap_write(raminit->syscon, raminit->reg, ctrl);
+ regmap_update_bits(raminit->syscon, raminit->reg, mask, ctrl);
/* clear START bit if start pulse is needed */
if (raminit->needs_pulse) {
ctrl &= ~(1 << raminit->bits.start);
- regmap_write(raminit->syscon, raminit->reg, ctrl);
+ regmap_update_bits(raminit->syscon, raminit->reg,
+ mask, ctrl);
}
ctrl |= 1 << raminit->bits.done;
--
2.1.0
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
