| Message ID | 20190828071941.32378-4-t-kristo@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | soc: ti: add OMAP PRM driver (for reset) | expand |
Hi Tero, On Wed, 2019-08-28 at 10:19 +0300, Tero Kristo wrote: > Poll for reset completion status during de-assertion of reset, otherwise > the IP in question might be accessed before it has left reset properly. > > Signed-off-by: Tero Kristo <t-kristo@ti.com> > --- > drivers/soc/ti/omap_prm.c | 20 ++++++++++++++++++++ > 1 file changed, 20 insertions(+) > > diff --git a/drivers/soc/ti/omap_prm.c b/drivers/soc/ti/omap_prm.c > index fd5c431f8736..afeb70761b27 100644 > --- a/drivers/soc/ti/omap_prm.c > +++ b/drivers/soc/ti/omap_prm.c > @@ -127,6 +127,7 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev, > u32 v; > int st_bit; > bool has_rstst; > + int timeout = 0; > > if (!_is_valid_reset(reset, id)) > return -EINVAL; > @@ -153,6 +154,25 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev, > v &= ~(1 << id); > writel_relaxed(v, reset->prm->base + reset->prm->data->rstctrl); > > + if (!has_rstst) > + return 0; > + > + /* wait for the status to be set */ > + while (1) { > + v = readl_relaxed(reset->prm->base + reset->prm->data->rstst); > + v &= 1 << st_bit; > + if (v) > + break; > + timeout++; > + if (timeout > OMAP_RESET_MAX_WAIT) { > + pr_err("%s: timedout waiting for %s:%lu\n", __func__, > + dev_name(rcdev->dev), id); > + return -EBUSY; > + } > + > + udelay(1); > + } This looks like you could use readl_relaxed_poll_timeout(_atomic) regards Philipp
On 29/08/2019 16:14, Philipp Zabel wrote: > Hi Tero, > > On Wed, 2019-08-28 at 10:19 +0300, Tero Kristo wrote: >> Poll for reset completion status during de-assertion of reset, otherwise >> the IP in question might be accessed before it has left reset properly. >> >> Signed-off-by: Tero Kristo <t-kristo@ti.com> >> --- >> drivers/soc/ti/omap_prm.c | 20 ++++++++++++++++++++ >> 1 file changed, 20 insertions(+) >> >> diff --git a/drivers/soc/ti/omap_prm.c b/drivers/soc/ti/omap_prm.c >> index fd5c431f8736..afeb70761b27 100644 >> --- a/drivers/soc/ti/omap_prm.c >> +++ b/drivers/soc/ti/omap_prm.c >> @@ -127,6 +127,7 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev, >> u32 v; >> int st_bit; >> bool has_rstst; >> + int timeout = 0; >> >> if (!_is_valid_reset(reset, id)) >> return -EINVAL; >> @@ -153,6 +154,25 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev, >> v &= ~(1 << id); >> writel_relaxed(v, reset->prm->base + reset->prm->data->rstctrl); >> >> + if (!has_rstst) >> + return 0; >> + >> + /* wait for the status to be set */ >> + while (1) { >> + v = readl_relaxed(reset->prm->base + reset->prm->data->rstst); >> + v &= 1 << st_bit; >> + if (v) >> + break; >> + timeout++; >> + if (timeout > OMAP_RESET_MAX_WAIT) { >> + pr_err("%s: timedout waiting for %s:%lu\n", __func__, >> + dev_name(rcdev->dev), id); >> + return -EBUSY; >> + } >> + >> + udelay(1); >> + } > > This looks like you could use > > readl_relaxed_poll_timeout(_atomic) Yeah true, let me change that. -Tero -- Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
diff --git a/drivers/soc/ti/omap_prm.c b/drivers/soc/ti/omap_prm.c index fd5c431f8736..afeb70761b27 100644 --- a/drivers/soc/ti/omap_prm.c +++ b/drivers/soc/ti/omap_prm.c @@ -127,6 +127,7 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev, u32 v; int st_bit; bool has_rstst; + int timeout = 0; if (!_is_valid_reset(reset, id)) return -EINVAL; @@ -153,6 +154,25 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev, v &= ~(1 << id); writel_relaxed(v, reset->prm->base + reset->prm->data->rstctrl); + if (!has_rstst) + return 0; + + /* wait for the status to be set */ + while (1) { + v = readl_relaxed(reset->prm->base + reset->prm->data->rstst); + v &= 1 << st_bit; + if (v) + break; + timeout++; + if (timeout > OMAP_RESET_MAX_WAIT) { + pr_err("%s: timedout waiting for %s:%lu\n", __func__, + dev_name(rcdev->dev), id); + return -EBUSY; + } + + udelay(1); + } + return 0; }
Poll for reset completion status during de-assertion of reset, otherwise the IP in question might be accessed before it has left reset properly. Signed-off-by: Tero Kristo <t-kristo@ti.com> --- drivers/soc/ti/omap_prm.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)