usb: dwc3: gadget: replace mdelay with udelay in the busy loop
There are two spots where we wait until the HW finishes processing a
certain command. Initially we had a few problems and we used 500ms as a
limit to be on a the safe side. Paul Zimmerman mentioned this is little too
much. After a debugging session, we noticed that we hardly ever go over 20us
and didn't pass 30usec so far. Using mdelay() seems way overloaded.
Giving the current numbers 500usec as the upper limit is more than enough.
Should it ever timeout then something is definitely wrong.
While here, also replace the type with u32 since long does not really
fit here.
Cc: Paul Zimmerman <paul.zimmerman@synopsys.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 7c014e9..b5d95f8 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -153,7 +153,7 @@
unsigned cmd, struct dwc3_gadget_ep_cmd_params *params)
{
struct dwc3_ep *dep = dwc->eps[ep];
- unsigned long timeout = 500;
+ u32 timeout = 500;
u32 reg;
dev_vdbg(dwc->dev, "%s: cmd '%s' params %08x %08x %08x\n",
@@ -175,7 +175,6 @@
}
/*
- * XXX Figure out a sane timeout here. 500ms is way too much.
* We can't sleep here, because it is also called from
* interrupt context.
*/
@@ -183,7 +182,7 @@
if (!timeout)
return -ETIMEDOUT;
- mdelay(1);
+ udelay(1);
} while (1);
}
@@ -1066,7 +1065,7 @@
static void dwc3_gadget_run_stop(struct dwc3 *dwc, int is_on)
{
u32 reg;
- unsigned long timeout = 500;
+ u32 timeout = 500;
reg = dwc3_readl(dwc->regs, DWC3_DCTL);
if (is_on)
@@ -1085,13 +1084,10 @@
if (reg & DWC3_DSTS_DEVCTRLHLT)
break;
}
- /*
- * XXX reduce the 500ms delay
- */
timeout--;
if (!timeout)
break;
- mdelay(1);
+ udelay(1);
} while (1);
dev_vdbg(dwc->dev, "gadget %s data soft-%s\n",