[PATCH 2/2] fbdev: radeon: stop use ktime_get() for HZ calibration

From: Arnd Bergmann
Date: Tue Nov 07 2017 - 09:13:57 EST


do_gettimeofday() is deprecated and a bit clumsy. This changes
radeon_probe_pll_params() over to using ktime_get() with monotonic
times. There is no need to check for negative values any more
since the monotonic clocksource cannot go backwards, but I'm
adding a check for zero-division in case of a bad clocksource.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/video/fbdev/aty/radeon_base.c | 18 +++++++-----------
1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/drivers/video/fbdev/aty/radeon_base.c b/drivers/video/fbdev/aty/radeon_base.c
index 8ad1643e7d1c..8b7048fbf6dc 100644
--- a/drivers/video/fbdev/aty/radeon_base.c
+++ b/drivers/video/fbdev/aty/radeon_base.c
@@ -583,8 +583,8 @@ static int radeon_probe_pll_params(struct radeonfb_info *rinfo)
int hTotal, vTotal, num, denom, m, n;
unsigned long long hz, vclk;
long xtal;
- struct timeval start_tv, stop_tv;
- long total_secs, total_usecs;
+ ktime_t start_time, stop_time;
+ u64 total_usecs;
int i;

/* Ugh, we cut interrupts, bad bad bad, but we want some precision
@@ -600,7 +600,7 @@ static int radeon_probe_pll_params(struct radeonfb_info *rinfo)
if (((INREG(CRTC_VLINE_CRNT_VLINE) >> 16) & 0x3ff) == 0)
break;

- do_gettimeofday(&start_tv);
+ start_time = ktime_get();

for(i=0; i<1000000; i++)
if (((INREG(CRTC_VLINE_CRNT_VLINE) >> 16) & 0x3ff) != 0)
@@ -610,18 +610,14 @@ static int radeon_probe_pll_params(struct radeonfb_info *rinfo)
if (((INREG(CRTC_VLINE_CRNT_VLINE) >> 16) & 0x3ff) == 0)
break;

- do_gettimeofday(&stop_tv);
+ stop_time = ktime_get();

local_irq_enable();

- total_secs = stop_tv.tv_sec - start_tv.tv_sec;
- if (total_secs > 10)
+ total_usecs = ktime_us_delta(stop_time, start_time);
+ if (total_usecs >= 10 * USEC_PER_SEC || total_usecs == 0)
return -1;
- total_usecs = stop_tv.tv_usec - start_tv.tv_usec;
- total_usecs += total_secs * 1000000;
- if (total_usecs < 0)
- total_usecs = -total_usecs;
- hz = 1000000/total_usecs;
+ hz = USEC_PER_SEC/(u32)total_usecs;

hTotal = ((INREG(CRTC_H_TOTAL_DISP) & 0x1ff) + 1) * 8;
vTotal = ((INREG(CRTC_V_TOTAL_DISP) & 0x3ff) + 1);
--
2.9.0