[PATCH v2 3/5] clk: renesas: rzv2h: Re-assert reset on deassert timeout

Tommaso Merciai posted 5 patches 1 month ago
[PATCH v2 3/5] clk: renesas: rzv2h: Re-assert reset on deassert timeout
Posted by Tommaso Merciai 1 month ago
Prevent issues during reset deassertion by re-asserting the reset if a
timeout occurs when trying to deassert. This ensures the reset line is in a
known state and improves reliability for hardware that may not immediately
clear the reset monitor bit.

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
---
v1->v2:
 - Collected GUytterhoeven tag
 - Removed dev_warn() in __rzg2l_cpg_assert()

 drivers/clk/renesas/rzv2h-cpg.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/renesas/rzv2h-cpg.c b/drivers/clk/renesas/rzv2h-cpg.c
index 58ccbae0f9046..35c5ff38e231e 100644
--- a/drivers/clk/renesas/rzv2h-cpg.c
+++ b/drivers/clk/renesas/rzv2h-cpg.c
@@ -854,6 +854,7 @@ static int __rzv2h_cpg_assert(struct reset_controller_dev *rcdev,
 	u32 mask = BIT(priv->resets[id].reset_bit);
 	u8 monbit = priv->resets[id].mon_bit;
 	u32 value = mask << 16;
+	int ret;
 
 	dev_dbg(rcdev->dev, "%s id:%ld offset:0x%x\n",
 		assert ? "assert" : "deassert", id, reg);
@@ -865,9 +866,15 @@ static int __rzv2h_cpg_assert(struct reset_controller_dev *rcdev,
 	reg = GET_RST_MON_OFFSET(priv->resets[id].mon_index);
 	mask = BIT(monbit);
 
-	return readl_poll_timeout_atomic(priv->base + reg, value,
-					 assert ? (value & mask) : !(value & mask),
-					 10, 200);
+	ret = readl_poll_timeout_atomic(priv->base + reg, value,
+					assert ? (value & mask) : !(value & mask),
+					10, 200);
+	if (ret && !assert) {
+		value = mask << 16;
+		writel(value, priv->base + GET_RST_OFFSET(priv->resets[id].reset_index));
+	}
+
+	return ret;
 }
 
 static int rzv2h_cpg_assert(struct reset_controller_dev *rcdev,
-- 
2.43.0
Re: [PATCH v2 3/5] clk: renesas: rzv2h: Re-assert reset on deassert timeout
Posted by Geert Uytterhoeven 4 weeks, 1 day ago
On Wed, 3 Sept 2025 at 10:28, Tommaso Merciai
<tommaso.merciai.xr@bp.renesas.com> wrote:
> Prevent issues during reset deassertion by re-asserting the reset if a
> timeout occurs when trying to deassert. This ensures the reset line is in a
> known state and improves reliability for hardware that may not immediately
> clear the reset monitor bit.
>
> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
> Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
> ---
> v1->v2:
>  - Collected GUytterhoeven tag
>  - Removed dev_warn() in __rzg2l_cpg_assert()

Thanks, will queue in renesas-clk for v6.18.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds