/*-------------------------------------------------------------------------*/
+#ifdef CONFIG_CPU_FREQ
+
+#include <linux/cpufreq.h>
+
+static void ehci_cpufreq_pause (struct ehci_hcd *ehci)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&ehci->lock, flags);
+ if (!ehci->cpufreq_changing++)
+ qh_inactivate_split_intr_qhs(ehci);
+ spin_unlock_irqrestore(&ehci->lock, flags);
+}
+
+static void ehci_cpufreq_unpause (struct ehci_hcd *ehci)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&ehci->lock, flags);
+ if (!--ehci->cpufreq_changing)
+ qh_reactivate_split_intr_qhs(ehci);
+ spin_unlock_irqrestore(&ehci->lock, flags);
+}
+
+/*
+ * ehci_cpufreq_notifier is needed to avoid MMF errors that occur when
+ * EHCI controllers that don't cache many uframes get delayed trying to
+ * read main memory during CPU frequency transitions. This can cause
+ * split interrupt transactions to not be completed in the required uframe.
+ * This has been observed on the Broadcom/ServerWorks HT1000 controller.
+ */
+static int ehci_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
+ void *data)
+{
+ struct ehci_hcd *ehci = container_of(nb, struct ehci_hcd,
+ cpufreq_transition);
+
+ switch (val) {
+ case CPUFREQ_PRECHANGE:
+ ehci_cpufreq_pause(ehci);
+ break;
+ case CPUFREQ_POSTCHANGE:
+ ehci_cpufreq_unpause(ehci);
+ break;
+ }
+ return 0;
+}
+
+#endif
+
+/*-------------------------------------------------------------------------*/
+
static void ehci_watchdog (unsigned long param)
{
struct ehci_hcd *ehci = (struct ehci_hcd *) param;
ehci_writel(ehci, 0, &ehci->regs->intr_enable);
spin_unlock_irq(&ehci->lock);
+#ifdef CONFIG_CPU_FREQ
+ cpufreq_unregister_notifier(&ehci->cpufreq_transition,
+ CPUFREQ_TRANSITION_NOTIFIER);
+#endif
/* let companion controllers work when we aren't */
ehci_writel(ehci, 0, &ehci->regs->configured_flag);
}
ehci->command = temp;
+#ifdef CONFIG_CPU_FREQ
+ INIT_LIST_HEAD(&ehci->split_intr_qhs);
+ /*
+ * If the EHCI controller caches enough uframes, this probably
+ * isn't needed unless there are so many low/full speed devices
+ * that the controller's can't cache it all.
+ */
+ ehci->cpufreq_transition.notifier_call = ehci_cpufreq_notifier;
+ cpufreq_register_notifier(&ehci->cpufreq_transition,
+ CPUFREQ_TRANSITION_NOTIFIER);
+#endif
return 0;
}
}
/*-------------------------------------------------------------------------*/
+#ifdef CONFIG_CPU_FREQ
+
+/* ignore/inactivate bit in QH hw_info1 */
+#define INACTIVATE_BIT __constant_cpu_to_le32(QH_INACTIVATE)
+
+#define HALT_BIT __constant_cpu_to_le32(QTD_STS_HALT)
+#define ACTIVE_BIT __constant_cpu_to_le32(QTD_STS_ACTIVE)
+#define STATUS_BIT __constant_cpu_to_le32(QTD_STS_STS)
+
+static int safe_to_modify_i (struct ehci_hcd *ehci, struct ehci_qh *qh)
+{
+ int now; /* current (frame * 8) + uframe */
+ int prev_start, next_start; /* uframes from/to split start */
+ int start_uframe = ffs(le32_to_cpup (&qh->hw_info2) & QH_SMASK);
+ int end_uframe = fls((le32_to_cpup (&qh->hw_info2) & QH_CMASK) >> 8);
+ int split_duration = end_uframe - start_uframe;
+
+ now = readl(&ehci->regs->frame_index) % (ehci->periodic_size << 3);
+
+ next_start = ((1024 << 3) + (qh->start << 3) + start_uframe - now) %
+ (qh->period << 3);
+ prev_start = (qh->period << 3) - next_start;
+
+ /*
+ * Make sure there will be at least one uframe when qh is safe.
+ */
+ if ((qh->period << 3) <= (ehci->i_thresh + 2 + split_duration))
+ /* never safe */
+ return -EINVAL;
+
+ /*
+ * Wait 1 uframe after transaction should have started, to make
+ * sure controller has time to write back overlay, so we can
+ * check QTD_STS_STS to see if transaction is in progress.
+ */
+ if ((next_start > ehci->i_thresh) && (prev_start > 1))
+ /* safe to set "i" bit if split isn't in progress */
+ return (qh->hw_token & STATUS_BIT) ? 0 : 1;
+ else
+ return 0;
+}
+
+/* Set inactivate bit for all the split interrupt QHs. */
+static void qh_inactivate_split_intr_qhs (struct ehci_hcd *ehci)
+{
+ struct ehci_qh *qh;
+ int not_done, safe;
+
+ do {
+ not_done = 0;
+ list_for_each_entry(qh, &ehci->split_intr_qhs,
+ split_intr_qhs) {
+ if (qh->hw_info1 & INACTIVATE_BIT)
+ /* already off */
+ continue;
+ /*
+ * To avoid setting "I" after the start split happens,
+ * don't set it if the QH might be cached in the
+ * controller. Some HCs (Broadcom/ServerWorks HT1000)
+ * will stop in the middle of a split transaction when
+ * the "I" bit is set.
+ */
+ safe = safe_to_modify_i(ehci, qh);
+ if (safe == 0) {
+ not_done = 1;
+ } else if (safe > 0) {
+ qh->was_active = qh->hw_token & ACTIVE_BIT;
+ qh->hw_info1 |= INACTIVATE_BIT;
+ }
+ }
+ } while (not_done);
+ wmb();
+}
+
+static void qh_reactivate_split_intr_qhs (struct ehci_hcd *ehci)
+{
+ struct ehci_qh *qh;
+ u32 token;
+ int not_done, safe;
+
+ do {
+ not_done = 0;
+ list_for_each_entry(qh, &ehci->split_intr_qhs, split_intr_qhs) {
+ if (!(qh->hw_info1 & INACTIVATE_BIT)) /* already on */
+ continue;
+ /*
+ * Don't reactivate if cached, or controller might
+ * overwrite overlay after we modify it!
+ */
+ safe = safe_to_modify_i(ehci, qh);
+ if (safe == 0) {
+ not_done = 1;
+ } else if (safe > 0) {
+ /* See EHCI 1.0 section 4.15.2.4. */
+ token = qh->hw_token;
+ qh->hw_token = (token | HALT_BIT) & ~ACTIVE_BIT;
+ wmb();
+ qh->hw_info1 &= ~INACTIVATE_BIT;
+ wmb();
+ qh->hw_token = (token & ~HALT_BIT) | qh->was_active;
+ }
+ }
+ } while (not_done);
+}
+#endif
/* periodic schedule slots have iso tds (normal or split) first, then a
* sparse tree for active interrupt transfers.
period, le32_to_cpup (&qh->hw_info2) & (QH_CMASK | QH_SMASK),
qh, qh->start, qh->usecs, qh->c_usecs);
+#ifdef CONFIG_CPU_FREQ
+ /*
+ * If low/full speed interrupt QHs are inactive (because of
+ * cpufreq changing processor speeds), start QH with I flag set--
+ * it will automatically be cleared when cpufreq is done.
+ */
+ if (ehci->cpufreq_changing)
+ if (!(qh->hw_info1 & (cpu_to_le32(1 << 13))))
+ qh->hw_info1 |= INACTIVATE_BIT;
+#endif
+
/* high bandwidth, or otherwise every microframe */
if (period == 0)
period = 1;
? ((qh->usecs + qh->c_usecs) / qh->period)
: (qh->usecs * 8);
+#ifdef CONFIG_CPU_FREQ
+ /* add qh to list of low/full speed interrupt QHs, if applicable */
+ if (!(qh->hw_info1 & (cpu_to_le32(1 << 13)))) {
+ list_add(&qh->split_intr_qhs, &ehci->split_intr_qhs);
+ }
+#endif
/* maybe enable periodic schedule processing */
if (!ehci->periodic_sched++)
return enable_periodic (ehci);
// THEN
// qh->hw_info1 |= __constant_cpu_to_le32 (1 << 7 /* "ignore" */);
+#ifdef CONFIG_CPU_FREQ
+ /* remove qh from list of low/full speed interrupt QHs */
+ if (!(qh->hw_info1 & (cpu_to_le32(1 << 13)))) {
+ list_del_init(&qh->split_intr_qhs);
+ }
+#endif
+
/* high bandwidth, or otherwise part of every microframe */
if ((period = qh->period) == 0)
period = 1;
__u32 hcs_params; /* cached register copy */
spinlock_t lock;
+#ifdef CONFIG_CPU_FREQ
+ struct notifier_block cpufreq_transition;
+ int cpufreq_changing;
+ struct list_head split_intr_qhs;
+#endif
+
/* async schedule support */
struct ehci_qh *async;
struct ehci_qh *reclaim;
__le32 hw_next; /* see EHCI 3.6.1 */
__le32 hw_info1; /* see EHCI 3.6.2 */
#define QH_HEAD 0x00008000
+#define QH_INACTIVATE 0x00000080
__le32 hw_info2; /* see EHCI 3.6.2 */
#define QH_SMASK 0x000000ff
#define QH_CMASK 0x0000ff00
unsigned short start; /* where polling starts */
#define NO_FRAME ((unsigned short)~0) /* pick new start */
struct usb_device *dev; /* access to TT */
+#ifdef CONFIG_CPU_FREQ
+ struct list_head split_intr_qhs; /* list of split qhs */
+ __le32 was_active; /* active bit before "i" set */
+#endif
} __attribute__ ((aligned (32)));
/*-------------------------------------------------------------------------*/
projects / linux-2.6-omap-h63xx.git / commitdiff