+++ /dev/null
-From 8b6aa431b277cc3c49c0c8be2b49b395d29325cf Mon Sep 17 00:00:00 2001
-From: John Cox <jc@kynesim.co.uk>
-Date: Thu, 11 Mar 2021 18:43:15 +0000
-Subject: [PATCH] media: rpivid: Add an enable count to irq claim Qs
-
-Add an enable count to the irq Q structures to allow the irq logic to
-block further callbacks if resources associated with the irq are not
-yet available.
-
-Signed-off-by: John Cox <jc@kynesim.co.uk>
----
- drivers/staging/media/rpivid/rpivid.h | 2 +
- drivers/staging/media/rpivid/rpivid_hw.c | 118 +++++++++++++++--------
- drivers/staging/media/rpivid/rpivid_hw.h | 3 +
- 3 files changed, 85 insertions(+), 38 deletions(-)
-
---- a/drivers/staging/media/rpivid/rpivid.h
-+++ b/drivers/staging/media/rpivid/rpivid.h
-@@ -151,6 +151,8 @@ struct rpivid_hw_irq_ctrl {
- struct rpivid_hw_irq_ent *irq;
- /* Non-zero => do not start a new job - outer layer sched pending */
- int no_sched;
-+ /* Enable count. -1 always OK, 0 do not sched, +ve shed & count down */
-+ int enable;
- /* Thread CB requested */
- bool thread_reqed;
- };
---- a/drivers/staging/media/rpivid/rpivid_hw.c
-+++ b/drivers/staging/media/rpivid/rpivid_hw.c
-@@ -42,35 +42,62 @@ static void pre_irq(struct rpivid_dev *d
- ient->cb = cb;
- ient->v = v;
-
-- // Not sure this lock is actually required
- spin_lock_irqsave(&ictl->lock, flags);
- ictl->irq = ient;
-+ ictl->no_sched++;
- spin_unlock_irqrestore(&ictl->lock, flags);
- }
-
--static void sched_claim(struct rpivid_dev * const dev,
-- struct rpivid_hw_irq_ctrl * const ictl)
-+/* Should be called from inside ictl->lock */
-+static inline bool sched_enabled(const struct rpivid_hw_irq_ctrl * const ictl)
- {
-- for (;;) {
-- struct rpivid_hw_irq_ent *ient = NULL;
-- unsigned long flags;
-+ return ictl->no_sched <= 0 && ictl->enable;
-+}
-
-- spin_lock_irqsave(&ictl->lock, flags);
-+/* Should be called from inside ictl->lock & after checking sched_enabled() */
-+static inline void set_claimed(struct rpivid_hw_irq_ctrl * const ictl)
-+{
-+ if (ictl->enable > 0)
-+ --ictl->enable;
-+ ictl->no_sched = 1;
-+}
-
-- if (--ictl->no_sched <= 0) {
-- ient = ictl->claim;
-- if (!ictl->irq && ient) {
-- ictl->claim = ient->next;
-- ictl->no_sched = 1;
-- }
-- }
-+/* Should be called from inside ictl->lock */
-+static struct rpivid_hw_irq_ent *get_sched(struct rpivid_hw_irq_ctrl * const ictl)
-+{
-+ struct rpivid_hw_irq_ent *ient;
-
-- spin_unlock_irqrestore(&ictl->lock, flags);
-+ if (!sched_enabled(ictl))
-+ return NULL;
-+
-+ ient = ictl->claim;
-+ if (!ient)
-+ return NULL;
-+ ictl->claim = ient->next;
-+
-+ set_claimed(ictl);
-+ return ient;
-+}
-
-- if (!ient)
-- break;
-+/* Run a callback & check to see if there is anything else to run */
-+static void sched_cb(struct rpivid_dev * const dev,
-+ struct rpivid_hw_irq_ctrl * const ictl,
-+ struct rpivid_hw_irq_ent *ient)
-+{
-+ while (ient) {
-+ unsigned long flags;
-
- ient->cb(dev, ient->v);
-+
-+ spin_lock_irqsave(&ictl->lock, flags);
-+
-+ /* Always dec no_sched after cb exec - must have been set
-+ * on entry to cb
-+ */
-+ --ictl->no_sched;
-+ ient = get_sched(ictl);
-+
-+ spin_unlock_irqrestore(&ictl->lock, flags);
- }
- }
-
-@@ -84,7 +111,7 @@ static void pre_thread(struct rpivid_dev
- ient->v = v;
- ictl->irq = ient;
- ictl->thread_reqed = true;
-- ictl->no_sched++;
-+ ictl->no_sched++; /* This is unwound in do_thread */
- }
-
- // Called in irq context
-@@ -96,17 +123,10 @@ static void do_irq(struct rpivid_dev * c
-
- spin_lock_irqsave(&ictl->lock, flags);
- ient = ictl->irq;
-- if (ient) {
-- ictl->no_sched++;
-- ictl->irq = NULL;
-- }
-+ ictl->irq = NULL;
- spin_unlock_irqrestore(&ictl->lock, flags);
-
-- if (ient) {
-- ient->cb(dev, ient->v);
--
-- sched_claim(dev, ictl);
-- }
-+ sched_cb(dev, ictl, ient);
- }
-
- static void do_claim(struct rpivid_dev * const dev,
-@@ -127,7 +147,7 @@ static void do_claim(struct rpivid_dev *
- ictl->tail->next = ient;
- ictl->tail = ient;
- ient = NULL;
-- } else if (ictl->no_sched || ictl->irq) {
-+ } else if (!sched_enabled(ictl)) {
- // Empty Q but other activity in progress so Q
- ictl->claim = ient;
- ictl->tail = ient;
-@@ -135,16 +155,34 @@ static void do_claim(struct rpivid_dev *
- } else {
- // Nothing else going on - schedule immediately and
- // prevent anything else scheduling claims
-- ictl->no_sched = 1;
-+ set_claimed(ictl);
- }
-
- spin_unlock_irqrestore(&ictl->lock, flags);
-
-- if (ient) {
-- ient->cb(dev, ient->v);
-+ sched_cb(dev, ictl, ient);
-+}
-
-- sched_claim(dev, ictl);
-- }
-+/* Enable n claims.
-+ * n < 0 set to unlimited (default on init)
-+ * n = 0 if previously unlimited then disable otherwise nop
-+ * n > 0 if previously unlimited then set to n enables
-+ * otherwise add n enables
-+ * The enable count is automatically decremented every time a claim is run
-+ */
-+static void do_enable_claim(struct rpivid_dev * const dev,
-+ int n,
-+ struct rpivid_hw_irq_ctrl * const ictl)
-+{
-+ unsigned long flags;
-+ struct rpivid_hw_irq_ent *ient;
-+
-+ spin_lock_irqsave(&ictl->lock, flags);
-+ ictl->enable = n < 0 ? -1 : ictl->enable <= 0 ? n : ictl->enable + n;
-+ ient = get_sched(ictl);
-+ spin_unlock_irqrestore(&ictl->lock, flags);
-+
-+ sched_cb(dev, ictl, ient);
- }
-
- static void ictl_init(struct rpivid_hw_irq_ctrl * const ictl)
-@@ -154,6 +192,8 @@ static void ictl_init(struct rpivid_hw_i
- ictl->tail = NULL;
- ictl->irq = NULL;
- ictl->no_sched = 0;
-+ ictl->enable = -1;
-+ ictl->thread_reqed = false;
- }
-
- static void ictl_uninit(struct rpivid_hw_irq_ctrl * const ictl)
-@@ -203,11 +243,7 @@ static void do_thread(struct rpivid_dev
-
- spin_unlock_irqrestore(&ictl->lock, flags);
-
-- if (ient) {
-- ient->cb(dev, ient->v);
--
-- sched_claim(dev, ictl);
-- }
-+ sched_cb(dev, ictl, ient);
- }
-
- static irqreturn_t rpivid_irq_thread(int irq, void *data)
-@@ -231,6 +267,12 @@ void rpivid_hw_irq_active1_thread(struct
- pre_thread(dev, ient, thread_cb, ctx, &dev->ic_active1);
- }
-
-+void rpivid_hw_irq_active1_enable_claim(struct rpivid_dev *dev,
-+ int n)
-+{
-+ do_enable_claim(dev, n, &dev->ic_active1);
-+}
-+
- void rpivid_hw_irq_active1_claim(struct rpivid_dev *dev,
- struct rpivid_hw_irq_ent *ient,
- rpivid_irq_callback ready_cb, void *ctx)
---- a/drivers/staging/media/rpivid/rpivid_hw.h
-+++ b/drivers/staging/media/rpivid/rpivid_hw.h
-@@ -272,6 +272,9 @@ static inline void apb_write_vc_len(cons
- ARG_IC_ICTRL_ACTIVE1_INT_SET |\
- ARG_IC_ICTRL_ACTIVE2_INT_SET)
-
-+/* Regulate claim Q */
-+void rpivid_hw_irq_active1_enable_claim(struct rpivid_dev *dev,
-+ int n);
- /* Auto release once all CBs called */
- void rpivid_hw_irq_active1_claim(struct rpivid_dev *dev,
- struct rpivid_hw_irq_ent *ient,
projects / openwrt / staging / chunkeey.git / blobdiff