Re: [Y2038] [PATCH] fbdev: radeon: Remove 'struct timeval' usage

On 3 June 2015 at 21:59, Tomi Valkeinen tomi.valkeinen@ti.com wrote:

On 25/05/15 07:07, Tina Ruchandani wrote:

...

'struct timeval' uses a 32-bit representation for the seconds field which will overflow in the year 2038 and beyond. This patch replaces the usage of 'struct timeval' with ktime_t which uses a 64-bit time representation and does not suffer from the y2038 problem. This patch is part of a larger effort to remove all instances of 'struct timeval', 'struct timespec', time_t and other 32-bit timekeeping variables from the kernel. The patch also replaces the use of real time (do_gettimeofday) with monotonic time (ktime_get).

Signed-off-by: Tina Ruchandani ruchandani.tina@gmail.com

drivers/video/fbdev/aty/radeon_base.c | 29 ++++++++++++++--------------- 1 file changed, 14 insertions(+), 15 deletions(-)

diff --git a/drivers/video/fbdev/aty/radeon_base.c b/drivers/video/fbdev/aty/radeon_base.c index 01237c8..9747e9e 100644 --- a/drivers/video/fbdev/aty/radeon_base.c +++ b/drivers/video/fbdev/aty/radeon_base.c @@ -64,6 +64,7 @@ #include <linux/slab.h> #include <linux/delay.h> #include <linux/time.h> +#include <linux/ktime.h> #include <linux/fb.h> #include <linux/ioport.h> #include <linux/init.h> @@ -461,8 +462,8 @@ 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, stop;
  

• s64 delta;
  int i;
  
  /* Ugh, we cut interrupts, bad bad bad, but we want some precision
  

@@ -478,7 +479,7 @@ 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 = ktime_get();
  
  for(i=0; i<1000000; i++)
          if (((INREG(CRTC_VLINE_CRNT_VLINE) >> 16) & 0x3ff) != 0)
  

@@ -487,20 +488,18 @@ static int radeon_probe_pll_params(struct radeonfb_info *rinfo) for(i=0; i<1000000; i++) if (((INREG(CRTC_VLINE_CRNT_VLINE) >> 16) & 0x3ff) == 0) break;

• do_gettimeofday(&stop_tv);
  

• stop = ktime_get();
  

• local_irq_enable();
  
  

• total_secs = stop_tv.tv_sec - start_tv.tv_sec;
  

• if (total_secs > 10)
  

• delta = ktime_us_delta(stop, start);
  

• /* Return -1 if more than 10 seconds have elapsed */
  

• if (delta > (10*1000000))
          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 = 1000000/delta;
  

This needs to be on of the do_div family.

Dave.