Re: [PATCH v2] reset: make shared pulsed reset controls re-triggerable
On Mon 16 Nov 2020 at 17:36, Philipp Zabel wrote: > On Fri, 2020-11-13 at 16:13 +0100, Jerome Brunet wrote: >> On Fri 13 Nov 2020 at 16:04, Philipp Zabel wrote: >> >> > On Fri, 2020-11-13 at 00:00 +0100, Amjad Ouled-Ameur wrote: >> > > The current reset framework API does not allow to release what is done by >> > > reset_control_reset(), IOW decrement triggered_count. Add the new >> > > reset_control_rearm() call to do so. >> > > >> > > When reset_control_reset() has been called once, the counter >> > > triggered_count, in the reset framework, is incremented i.e the resource >> > > under the reset is in-use and the reset should not be done again. >> > > reset_control_rearm() would be the way to state that the resource is >> > > no longer used and, that from the caller's perspective, the reset can be >> > > fired again if necessary. >> > > >> > > Signed-off-by: Amjad Ouled-Ameur >> > > Reported-by: Jerome Brunet >> > > --- >> > > Change since v1: [0] >> > > * Renamed the new call from reset_control_(array_)resettable to >> > > reset_control_(array_)rearm >> > > * Open-coded reset_control_array_rearm to check for errors before >> > > decrementing triggered_count because we cannot roll back in case an >> > > error occurs while decrementing one of the rstc. >> > > * Reworded the new call's description. >> > >> > Thank you, applied to reset/next. >> >> Hi Philipp, >> >> Would it be possible to get an immutable branch/tag with this ? >> It would allow to move forward on the USB side, without waiting for the >> next rc1. > > Here you go, > > The following changes since commit 3650b228f83adda7e5ee532e2b90429c03f7b9ec: > > Linux 5.10-rc1 (2020-10-25 15:14:11 -0700) > > are available in the Git repository at: > > git://git.pengutronix.de/git/pza/linux.git reset/shared-retrigger > > for you to fetch changes up to 557acb3d2cd9c82de19f944f6cc967a347735385: > > reset: make shared pulsed reset controls re-triggerable (2020-11-16 > 17:05:28 +0100) > > > Amjad Ouled-Ameur (1): > reset: make shared pulsed reset controls re-triggerable > > drivers/reset/core.c | 73 > +++ > include/linux/reset.h | 1 + > 2 files changed, 74 insertions(+) > Thx Philipp ! > regards > Philipp
Re: [PATCH v2] reset: make shared pulsed reset controls re-triggerable
On Fri, 2020-11-13 at 16:13 +0100, Jerome Brunet wrote: > On Fri 13 Nov 2020 at 16:04, Philipp Zabel wrote: > > > On Fri, 2020-11-13 at 00:00 +0100, Amjad Ouled-Ameur wrote: > > > The current reset framework API does not allow to release what is done by > > > reset_control_reset(), IOW decrement triggered_count. Add the new > > > reset_control_rearm() call to do so. > > > > > > When reset_control_reset() has been called once, the counter > > > triggered_count, in the reset framework, is incremented i.e the resource > > > under the reset is in-use and the reset should not be done again. > > > reset_control_rearm() would be the way to state that the resource is > > > no longer used and, that from the caller's perspective, the reset can be > > > fired again if necessary. > > > > > > Signed-off-by: Amjad Ouled-Ameur > > > Reported-by: Jerome Brunet > > > --- > > > Change since v1: [0] > > > * Renamed the new call from reset_control_(array_)resettable to > > > reset_control_(array_)rearm > > > * Open-coded reset_control_array_rearm to check for errors before > > > decrementing triggered_count because we cannot roll back in case an > > > error occurs while decrementing one of the rstc. > > > * Reworded the new call's description. > > > > Thank you, applied to reset/next. > > Hi Philipp, > > Would it be possible to get an immutable branch/tag with this ? > It would allow to move forward on the USB side, without waiting for the > next rc1. Here you go, The following changes since commit 3650b228f83adda7e5ee532e2b90429c03f7b9ec: Linux 5.10-rc1 (2020-10-25 15:14:11 -0700) are available in the Git repository at: git://git.pengutronix.de/git/pza/linux.git reset/shared-retrigger for you to fetch changes up to 557acb3d2cd9c82de19f944f6cc967a347735385: reset: make shared pulsed reset controls re-triggerable (2020-11-16 17:05:28 +0100) Amjad Ouled-Ameur (1): reset: make shared pulsed reset controls re-triggerable drivers/reset/core.c | 73 +++ include/linux/reset.h | 1 + 2 files changed, 74 insertions(+) regards Philipp
Re: [PATCH v2] reset: make shared pulsed reset controls re-triggerable
On 13/11/2020 16:04, Philipp Zabel wrote: On Fri, 2020-11-13 at 00:00 +0100, Amjad Ouled-Ameur wrote: The current reset framework API does not allow to release what is done by reset_control_reset(), IOW decrement triggered_count. Add the new reset_control_rearm() call to do so. When reset_control_reset() has been called once, the counter triggered_count, in the reset framework, is incremented i.e the resource under the reset is in-use and the reset should not be done again. reset_control_rearm() would be the way to state that the resource is no longer used and, that from the caller's perspective, the reset can be fired again if necessary. Signed-off-by: Amjad Ouled-Ameur Reported-by: Jerome Brunet --- Change since v1: [0] * Renamed the new call from reset_control_(array_)resettable to reset_control_(array_)rearm * Open-coded reset_control_array_rearm to check for errors before decrementing triggered_count because we cannot roll back in case an error occurs while decrementing one of the rstc. * Reworded the new call's description. Thank you, applied to reset/next. regards Philipp Thank you for reviewing and approving my patch ! Furthermore, I think your idea of open coding reset_control_array_rearm was accurate, and should be also applied to reset_control_array_reset() and reset_control_array_(de)assert() What do you think ? In case you agree it is necessary to do so, I can work out an upcoming patchset to fix this matter. Best, Amjad
Re: [PATCH v2] reset: make shared pulsed reset controls re-triggerable
On Fri 13 Nov 2020 at 16:04, Philipp Zabel wrote: > On Fri, 2020-11-13 at 00:00 +0100, Amjad Ouled-Ameur wrote: >> The current reset framework API does not allow to release what is done by >> reset_control_reset(), IOW decrement triggered_count. Add the new >> reset_control_rearm() call to do so. >> >> When reset_control_reset() has been called once, the counter >> triggered_count, in the reset framework, is incremented i.e the resource >> under the reset is in-use and the reset should not be done again. >> reset_control_rearm() would be the way to state that the resource is >> no longer used and, that from the caller's perspective, the reset can be >> fired again if necessary. >> >> Signed-off-by: Amjad Ouled-Ameur >> Reported-by: Jerome Brunet >> --- >> Change since v1: [0] >> * Renamed the new call from reset_control_(array_)resettable to >> reset_control_(array_)rearm >> * Open-coded reset_control_array_rearm to check for errors before >> decrementing triggered_count because we cannot roll back in case an >> error occurs while decrementing one of the rstc. >> * Reworded the new call's description. > > Thank you, applied to reset/next. Hi Philipp, Would it be possible to get an immutable branch/tag with this ? It would allow to move forward on the USB side, without waiting for the next rc1. Thx Jerome > > regards > Philipp
Re: [PATCH v2] reset: make shared pulsed reset controls re-triggerable
On Fri, 2020-11-13 at 00:00 +0100, Amjad Ouled-Ameur wrote: > The current reset framework API does not allow to release what is done by > reset_control_reset(), IOW decrement triggered_count. Add the new > reset_control_rearm() call to do so. > > When reset_control_reset() has been called once, the counter > triggered_count, in the reset framework, is incremented i.e the resource > under the reset is in-use and the reset should not be done again. > reset_control_rearm() would be the way to state that the resource is > no longer used and, that from the caller's perspective, the reset can be > fired again if necessary. > > Signed-off-by: Amjad Ouled-Ameur > Reported-by: Jerome Brunet > --- > Change since v1: [0] > * Renamed the new call from reset_control_(array_)resettable to > reset_control_(array_)rearm > * Open-coded reset_control_array_rearm to check for errors before > decrementing triggered_count because we cannot roll back in case an > error occurs while decrementing one of the rstc. > * Reworded the new call's description. Thank you, applied to reset/next. regards Philipp
Re: [PATCH v2] reset: make shared pulsed reset controls re-triggerable
Please find in this patchset [0] a use case of the reset_control_rearm() call
on some of meson usb drivers:
[0]
https://lore.kernel.org/lkml/20201113000508.14702-1-aouledam...@baylibre.com/
On 13/11/2020 00:00, Amjad Ouled-Ameur wrote:
The current reset framework API does not allow to release what is done by
reset_control_reset(), IOW decrement triggered_count. Add the new
reset_control_rearm() call to do so.
When reset_control_reset() has been called once, the counter
triggered_count, in the reset framework, is incremented i.e the resource
under the reset is in-use and the reset should not be done again.
reset_control_rearm() would be the way to state that the resource is
no longer used and, that from the caller's perspective, the reset can be
fired again if necessary.
Signed-off-by: Amjad Ouled-Ameur
Reported-by: Jerome Brunet
---
Change since v1: [0]
* Renamed the new call from reset_control_(array_)resettable to
reset_control_(array_)rearm
* Open-coded reset_control_array_rearm to check for errors before
decrementing triggered_count because we cannot roll back in case an
error occurs while decrementing one of the rstc.
* Reworded the new call's description.
[0] https://lore.kernel.org/lkml/20201001132758.12280-1-aouledam...@baylibre.com
drivers/reset/core.c | 73 +++
include/linux/reset.h | 1 +
2 files changed, 74 insertions(+)
diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index a2df88e90011..34e89aa0fb5e 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -208,6 +208,39 @@ static int reset_control_array_reset(struct
reset_control_array *resets)
return 0;
}
+static int reset_control_array_rearm(struct reset_control_array *resets)
+{
+ struct reset_control *rstc;
+ int i;
+
+ for (i = 0; i < resets->num_rstcs; i++) {
+ rstc = resets->rstc[i];
+
+ if (!rstc)
+ continue;
+
+ if (WARN_ON(IS_ERR(rstc)))
+ return -EINVAL;
+
+ if (rstc->shared) {
+ if (WARN_ON(atomic_read(>deassert_count) != 0))
+ return -EINVAL;
+ } else {
+ if (!rstc->acquired)
+ return -EPERM;
+ }
+ }
+
+ for (i = 0; i < resets->num_rstcs; i++) {
+ rstc = resets->rstc[i];
+
+ if (rstc && rstc->shared)
+ WARN_ON(atomic_dec_return(>triggered_count) < 0);
+ }
+
+ return 0;
+}
+
static int reset_control_array_assert(struct reset_control_array *resets)
{
int ret, i;
@@ -325,6 +358,46 @@ int reset_control_reset(struct reset_control *rstc)
}
EXPORT_SYMBOL_GPL(reset_control_reset);
+/**
+ * reset_control_rearm - allow shared reset line to be re-triggered"
+ * @rstc: reset controller
+ *
+ * On a shared reset line the actual reset pulse is only triggered once for the
+ * lifetime of the reset_control instance, except if this call is used.
+ *
+ * Calls to this function must be balanced with calls to reset_control_reset,
+ * a warning is thrown in case triggered_count ever dips below 0.
+ *
+ * Consumers must not use reset_control_(de)assert on shared reset lines when
+ * reset_control_reset or reset_control_rearm have been used.
+ *
+ * If rstc is NULL the function will just return 0.
+ */
+int reset_control_rearm(struct reset_control *rstc)
+{
+ if (!rstc)
+ return 0;
+
+ if (WARN_ON(IS_ERR(rstc)))
+ return -EINVAL;
+
+ if (reset_control_is_array(rstc))
+ return reset_control_array_rearm(rstc_to_array(rstc));
+
+ if (rstc->shared) {
+ if (WARN_ON(atomic_read(>deassert_count) != 0))
+ return -EINVAL;
+
+ WARN_ON(atomic_dec_return(>triggered_count) < 0);
+ } else {
+ if (!rstc->acquired)
+ return -EPERM;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(reset_control_rearm);
+
/**
* reset_control_assert - asserts the reset line
* @rstc: reset controller
diff --git a/include/linux/reset.h b/include/linux/reset.h
index 05aa9f440f48..439fec7112a9 100644
--- a/include/linux/reset.h
+++ b/include/linux/reset.h
@@ -13,6 +13,7 @@ struct reset_control;
#ifdef CONFIG_RESET_CONTROLLER
int reset_control_reset(struct reset_control *rstc);
+int reset_control_rearm(struct reset_control *rstc);
int reset_control_assert(struct reset_control *rstc);
int reset_control_deassert(struct reset_control *rstc);
int reset_control_status(struct reset_control *rstc);
[PATCH v2] reset: make shared pulsed reset controls re-triggerable
The current reset framework API does not allow to release what is done by
reset_control_reset(), IOW decrement triggered_count. Add the new
reset_control_rearm() call to do so.
When reset_control_reset() has been called once, the counter
triggered_count, in the reset framework, is incremented i.e the resource
under the reset is in-use and the reset should not be done again.
reset_control_rearm() would be the way to state that the resource is
no longer used and, that from the caller's perspective, the reset can be
fired again if necessary.
Signed-off-by: Amjad Ouled-Ameur
Reported-by: Jerome Brunet
---
Change since v1: [0]
* Renamed the new call from reset_control_(array_)resettable to
reset_control_(array_)rearm
* Open-coded reset_control_array_rearm to check for errors before
decrementing triggered_count because we cannot roll back in case an
error occurs while decrementing one of the rstc.
* Reworded the new call's description.
[0] https://lore.kernel.org/lkml/20201001132758.12280-1-aouledam...@baylibre.com
drivers/reset/core.c | 73 +++
include/linux/reset.h | 1 +
2 files changed, 74 insertions(+)
diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index a2df88e90011..34e89aa0fb5e 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -208,6 +208,39 @@ static int reset_control_array_reset(struct
reset_control_array *resets)
return 0;
}
+static int reset_control_array_rearm(struct reset_control_array *resets)
+{
+ struct reset_control *rstc;
+ int i;
+
+ for (i = 0; i < resets->num_rstcs; i++) {
+ rstc = resets->rstc[i];
+
+ if (!rstc)
+ continue;
+
+ if (WARN_ON(IS_ERR(rstc)))
+ return -EINVAL;
+
+ if (rstc->shared) {
+ if (WARN_ON(atomic_read(>deassert_count) != 0))
+ return -EINVAL;
+ } else {
+ if (!rstc->acquired)
+ return -EPERM;
+ }
+ }
+
+ for (i = 0; i < resets->num_rstcs; i++) {
+ rstc = resets->rstc[i];
+
+ if (rstc && rstc->shared)
+ WARN_ON(atomic_dec_return(>triggered_count) < 0);
+ }
+
+ return 0;
+}
+
static int reset_control_array_assert(struct reset_control_array *resets)
{
int ret, i;
@@ -325,6 +358,46 @@ int reset_control_reset(struct reset_control *rstc)
}
EXPORT_SYMBOL_GPL(reset_control_reset);
+/**
+ * reset_control_rearm - allow shared reset line to be re-triggered"
+ * @rstc: reset controller
+ *
+ * On a shared reset line the actual reset pulse is only triggered once for the
+ * lifetime of the reset_control instance, except if this call is used.
+ *
+ * Calls to this function must be balanced with calls to reset_control_reset,
+ * a warning is thrown in case triggered_count ever dips below 0.
+ *
+ * Consumers must not use reset_control_(de)assert on shared reset lines when
+ * reset_control_reset or reset_control_rearm have been used.
+ *
+ * If rstc is NULL the function will just return 0.
+ */
+int reset_control_rearm(struct reset_control *rstc)
+{
+ if (!rstc)
+ return 0;
+
+ if (WARN_ON(IS_ERR(rstc)))
+ return -EINVAL;
+
+ if (reset_control_is_array(rstc))
+ return reset_control_array_rearm(rstc_to_array(rstc));
+
+ if (rstc->shared) {
+ if (WARN_ON(atomic_read(>deassert_count) != 0))
+ return -EINVAL;
+
+ WARN_ON(atomic_dec_return(>triggered_count) < 0);
+ } else {
+ if (!rstc->acquired)
+ return -EPERM;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(reset_control_rearm);
+
/**
* reset_control_assert - asserts the reset line
* @rstc: reset controller
diff --git a/include/linux/reset.h b/include/linux/reset.h
index 05aa9f440f48..439fec7112a9 100644
--- a/include/linux/reset.h
+++ b/include/linux/reset.h
@@ -13,6 +13,7 @@ struct reset_control;
#ifdef CONFIG_RESET_CONTROLLER
int reset_control_reset(struct reset_control *rstc);
+int reset_control_rearm(struct reset_control *rstc);
int reset_control_assert(struct reset_control *rstc);
int reset_control_deassert(struct reset_control *rstc);
int reset_control_status(struct reset_control *rstc);
--
2.17.1
