From a53b30716c607e8a8e036d765e41cd8a88d8205f Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Fri, 12 Aug 2022 19:08:02 +0200 Subject: [PATCH] soc: imx: gpcv2: Assert reset before ungating clock [ 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 Reviewed-by: Fabio Estevam Reviewed-by: Lucas Stach Signed-off-by: Shawn Guo Signed-off-by: Sasha Levin --- 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 b4aa284..4dc3a3f 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 */ -- 2.7.4