When compiling for i686, drivers/infiniband/hw/cxgb4/device.o 

fails to compile:

drivers/infiniband/hw/cxgb4/device.c: In function 'wr_log_show':

include/linux/ktime.h:84:36: error: 'prev_time.tv64' may be used uninitialized in this function [-Werror=maybe-uninitialized]

({ (ktime_t){ .tv64 = (lhs).tv64 - (rhs).tv64 }; })

^

drivers/infiniband/hw/cxgb4/device.c:133:10: note: 'prev_time.tv64' was declared here

ktime_t prev_time;

^

cc1: all warnings being treated as errors

make[5]: *** [drivers/infiniband/hw/cxgb4/device.o] Error 1

I don't know why x86_64 is compiling without this patch.

Compiler (gcc) version dependence?

diff -up ./drivers/infiniband/hw/cxgb4/device.c.tv64 ./drivers/infiniband/hw/cxgb4/device.c

--- ./drivers/infiniband/hw/cxgb4/device.c.tv64	2018-10-05 05:18:19.000000000 +0900

+++ ./drivers/infiniband/hw/cxgb4/device.c	2018-11-01 09:34:48.000000000 +0900

@@ -130,7 +130,7 @@ void c4iw_log_wr_stats(struct t4_wq *wq,

 static int wr_log_show(struct seq_file *seq, void *v)

 {

 	struct c4iw_dev *dev = seq->private;

-	ktime_t prev_time;

+	ktime_t prev_time = { .tv64 = 0 };

 	struct wr_log_entry *lep;

 	int prev_time_set = 0;

 	int idx, end;