Eric Lee / smarc-uboot | Embedian Git Server

Commit 2cd1b57220697ac47e4a63fb6a0a79eda2217f9d

Authored by Stephen Warren 2013-12-06 03:08:09 +0800

Committed by Tom Rini 2013-12-13 22:15:33 +0800

Exists in master and in 50 other branches

time: fix usec_to_tick()

Commit 8dfafdde88eb ("Introduce common timer functions") created a
common definition of usec_to_tick() which had a couple problems:

static unsigned long long usec_to_tick(unsigned long usec)
{
       uint64_t tick = usec * get_tbclk();

That likely overflows.

       usec *= get_tbclk();

That was an attempt to fix it by performing the multiply after the
promotion of usec to 64-bit, but was applied to the wrong variable,
which was never used.

This patch fixes these issues. A user-visible symptom of the problem was
the e.g. "dhcp zImage" using an ASIX USB Ethernet dongle would print:

Waiting for Ethernet connection... unable to connect.

... with no delay before "unable to connect". There are likely other
symptoms.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Rob Herring <rob.herring@calxeda.com>

Showing 1 changed file with 2 additions and 2 deletions Side-by-side Diff

lib/time.c

lib/time.c

Diff comments View file @ 2cd1b57

...	...	@@ -71,8 +71,8 @@
71	71	}
72	72	static unsigned long long usec_to_tick(unsigned long usec)
73	73	{
74		- uint64_t tick = usec * get_tbclk();
75		- usec *= get_tbclk();
	74	+ uint64_t tick = usec;
	75	+ tick *= get_tbclk();
76	76	do_div(tick, 1000000);
77	77	return tick;
78	78	}