On Fri, Oct 23, 2015 at 12:45 AM, Arnd Bergmann arnd@arndb.de wrote:
On Thursday 22 October 2015 23:09:20 Amitoj Kaur Chawla wrote:
This patch replaces timeval with timespec64 as 32 bit 'struct timeval' will not give current time beyond 2038.
This also changes the code to use ktime_get_real_ts64() which returns a 'struct timespec64' instead of do_gettimeofday() which returns a 'struct timeval'
Signed-off-by: Amitoj Kaur Chawla amitoj1606@gmail.com
Looks almost right, except for one bit:
drivers/misc/ibmasm/ibmasm.h | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/misc/ibmasm/ibmasm.h b/drivers/misc/ibmasm/ibmasm.h index 9b08344..0c7bb6d 100644 --- a/drivers/misc/ibmasm/ibmasm.h +++ b/drivers/misc/ibmasm/ibmasm.h @@ -34,6 +34,7 @@ #include <linux/kref.h> #include <linux/device.h> #include <linux/input.h> +#include <linux/time64.h>
/* Driver identification */ #define DRIVER_NAME "ibmasm" @@ -53,9 +54,9 @@ extern int ibmasm_debug;
static inline char *get_timestamp(char *buf) {
struct timeval now;do_gettimeofday(&now);sprintf(buf, "%lu.%lu", now.tv_sec, now.tv_usec);
struct timespec64 now;ktime_get_real_ts64(&now);sprintf(buf, "%lu.%lu", now.tv_sec, now.tv_nsec / NSEC_PER_USEC); return buf;now.tv_sec is using a 'time_t' a.k.a. 'long' on 64-bit architectures, but a 'time64_t' a.k.a. 'long long' on 32-bit architectures. This is a bit nonintuitive, but please change the format string to %llu for the first argument and add a corresponding cast to 's64' or 'long long', so we actually print the correct data and do not get a compiler warning.
The tv_nsec argument is always 'long', on both 32-bit and 64-bit architectures, so there is no warning and we correctly print the number. However, there is a preexisting bug in the format string that you should fix while you are here: %lu drops leading zeroes, which results in something like "12345678.1234" where we want to see "1234567.001234". Please change the format string to add the correct number of leading zeroes here.
Just to clarify, I should change this to sprintf(buf, "%llu.%8.8lu", now.tv_sec, now.tv_nsec / NSEC_PER_USEC);
As you seem to generally be doing well with the trivial patches, please move on to the 'simple' category next. I should also add a few more 'medium' level tasks but need to pick them carefully first.
Okay! Next patches will be the simple tasks. Also, I couldn't find the tutorial you mentioned for compiling, can you help me out some there?
Thanks,