+static void __d40_config_set_event(struct d40_chan *d40c, bool enable,
+ u32 event, int reg)
+{
+ void __iomem *addr = d40c->base->virtbase + D40_DREG_PCBASE
+ + d40c->phy_chan->num * D40_DREG_PCDELTA + reg;
+ int tries;
+
+ if (!enable) {
+ writel((D40_DEACTIVATE_EVENTLINE << D40_EVENTLINE_POS(event))
+ | ~D40_EVENTLINE_MASK(event), addr);
+ return;
+ }
+
+ /*
+ * The hardware sometimes doesn't register the enable when src and dst
+ * event lines are active on the same logical channel. Retry to ensure
+ * it does. Usually only one retry is sufficient.
+ */
+ tries = 100;
+ while (--tries) {
+ writel((D40_ACTIVATE_EVENTLINE << D40_EVENTLINE_POS(event))
+ | ~D40_EVENTLINE_MASK(event), addr);
+
+ if (readl(addr) & D40_EVENTLINE_MASK(event))
+ break;
+ }
+
+ if (tries != 99)
+ dev_dbg(chan2dev(d40c),
+ "[%s] workaround enable S%cLNK (%d tries)\n",
+ __func__, reg == D40_CHAN_REG_SSLNK ? 'S' : 'D',
+ 100 - tries);
+
+ WARN_ON(!tries);
+}
+