[PATCH v2] soc: imx: gpcv2: Assert reset before ungating clock
Marek Vasut
marex at denx.de
Tue Aug 2 16:37:23 PDT 2022
In case the power domain clock are ungated before the reset is asserted,
the system might freeze completely. This is likely due to a device is an
undefined state being attached to bus, which sporadically leads to a bus
hang. Assert the reset before the clock are enabled to assure the device
is in defined state before being attached to bus.
Fixes: fe58c887fb8ca ("soc: imx: gpcv2: add support for optional resets")
Signed-off-by: Marek Vasut <marex at denx.de>
Cc: Fabio Estevam <festevam at denx.de>
Cc: Frieder Schrempf <frieder.schrempf at kontron.de>
Cc: Lucas Stach <l.stach at pengutronix.de>
Cc: NXP Linux Team <linux-imx at nxp.com>
Cc: Peng Fan <peng.fan at nxp.com>
Cc: Shawn Guo <shawnguo at kernel.org>
To: linux-arm-kernel at lists.infradead.org
---
V2: - Always assert the reset before enabling clock
- Update commit message
- Add Fixes tag
---
drivers/soc/imx/gpcv2.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/soc/imx/gpcv2.c b/drivers/soc/imx/gpcv2.c
index 85aa86e1338af..f38a4420e94a6 100644
--- a/drivers/soc/imx/gpcv2.c
+++ b/drivers/soc/imx/gpcv2.c
@@ -333,6 +333,11 @@ static int imx_pgc_power_up(struct generic_pm_domain *genpd)
}
}
+ reset_control_assert(domain->reset);
+
+ /* delays for reset to propagate */
+ udelay(5);
+
/* Enable reset clocks for all devices in the domain */
ret = clk_bulk_prepare_enable(domain->num_clks, domain->clks);
if (ret) {
@@ -340,8 +345,6 @@ static int imx_pgc_power_up(struct generic_pm_domain *genpd)
goto out_regulator_disable;
}
- reset_control_assert(domain->reset);
-
if (domain->bits.pxx) {
/* request the domain to power up */
regmap_update_bits(domain->regmap, domain->regs->pup,
--
2.35.1
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