soc: imx: gpcv2: Assert reset before ungating clock

[ Upstream commit df88005 ]

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: fe58c88 ("soc: imx: gpcv2: add support for optional resets")
Signed-off-by: Marek Vasut <marex@denx.de>
Reviewed-by: Fabio Estevam <festevam@denx.de>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/soc/imx/gpcv2.c

@@ -333,14 +333,17 @@ static int imx_pgc_power_up(struct generic_pm_domain *genpd)
 		}
 	}
 
+	reset_control_assert(domain->reset);
+
 	/* Enable reset clocks for all devices in the domain */
 	ret = clk_bulk_prepare_enable(domain->num_clks, domain->clks);
 	if (ret) {
 		dev_err(domain->dev, "failed to enable reset clocks\n");
 		goto out_regulator_disable;
 	}
 
-	reset_control_assert(domain->reset);
+	/* delays for reset to propagate */
+	udelay(5);
 
 	if (domain->bits.pxx) {
 		/* request the domain to power up */