@@ -39,17 +39,20 @@ static int reset_simple_set(struct reset_controller_dev *rcdev,
int reg_width = sizeof(u32);
int bank = id / (reg_width * BITS_PER_BYTE);
int offset = id % (reg_width * BITS_PER_BYTE);
+ void __iomem *addr = data->membase + (bank * reg_width);
unsigned long flags;
u32 reg;
spin_lock_irqsave(&data->lock, flags);
- reg = readl(data->membase + (bank * reg_width));
+ reg = readl(addr);
if (assert ^ data->inverted)
reg |= BIT(offset);
else
reg &= ~BIT(offset);
- writel(reg, data->membase + (bank * reg_width));
+ writel(reg, addr);
+ /* Read back to make sure the write doesn't linger in a store buffer */
+ readl(addr);
spin_unlock_irqrestore(&data->lock, flags);
Read back the register after setting or clearing a reset bit to make sure that the changes are applied to the reset controller hardware. Theoretically, this avoids the write to stay stuck in a store buffer during the delay of an assert-delay-deassert sequence, and makes sure that the reset really is asserted for the specified duration. Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> --- Changes since v1: - Rebased to only modify the reset_simple_set helper function. --- drivers/reset/reset-simple.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)