| Message ID | 20220812170802.205244-1-marex@denx.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3] soc: imx: gpcv2: Assert reset before ungating clock | expand |
Hi Marek, On 12/08/2022 14:08, Marek Vasut wrote: > 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>
Am Freitag, dem 12.08.2022 um 19:08 +0200 schrieb Marek Vasut: > 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: Lucas Stach <l.stach@pengutronix.de> > --- > Cc: Fabio Estevam <festevam@denx.de> > Cc: Frieder Schrempf <frieder.schrempf@kontron.de> > Cc: Lucas Stach <l.stach@pengutronix.de> > Cc: NXP Linux Team <linux-imx@nxp.com> > Cc: Peng Fan <peng.fan@nxp.com> > Cc: Shawn Guo <shawnguo@kernel.org> > To: linux-arm-kernel@lists.infradead.org > --- > V2: - Always assert the reset before enabling clock > - Update commit message > - Add Fixes tag > V3: Move the extra delay past clk_prepare_enable() > --- > 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 6383a4edc3607..88aee59730e39 100644 > --- a/drivers/soc/imx/gpcv2.c > +++ b/drivers/soc/imx/gpcv2.c > @@ -335,6 +335,8 @@ 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) { > @@ -342,7 +344,8 @@ 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 */
On Fri, Aug 12, 2022 at 07:08:02PM +0200, Marek Vasut wrote: > 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> Applied, thanks!
diff --git a/drivers/soc/imx/gpcv2.c b/drivers/soc/imx/gpcv2.c index 6383a4edc3607..88aee59730e39 100644 --- a/drivers/soc/imx/gpcv2.c +++ b/drivers/soc/imx/gpcv2.c @@ -335,6 +335,8 @@ 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) { @@ -342,7 +344,8 @@ 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 */
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> --- Cc: Fabio Estevam <festevam@denx.de> Cc: Frieder Schrempf <frieder.schrempf@kontron.de> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: NXP Linux Team <linux-imx@nxp.com> Cc: Peng Fan <peng.fan@nxp.com> Cc: Shawn Guo <shawnguo@kernel.org> To: linux-arm-kernel@lists.infradead.org --- V2: - Always assert the reset before enabling clock - Update commit message - Add Fixes tag V3: Move the extra delay past clk_prepare_enable() --- drivers/soc/imx/gpcv2.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)