| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.15 053/121] soc: imx: gpcv2: Assert reset before ungating clock | Date | Tue, 13 Sep 2022 16:04:04 +0200 |
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From: Marek Vasut <marex@denx.de>
[ Upstream commit df88005bd81b80c944d185554e264a4b0f993c37 ]
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@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 | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/soc/imx/gpcv2.c b/drivers/soc/imx/gpcv2.c index b4aa28420f2a8..4dc3a3f73511e 100644 --- a/drivers/soc/imx/gpcv2.c +++ b/drivers/soc/imx/gpcv2.c @@ -237,6 +237,8 @@ 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) { @@ -244,7 +246,8 @@ static int imx_pgc_power_up(struct generic_pm_domain *genpd) 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 */ -- 2.35.1
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