sysfsgpio: remove ignoring return value build warning

fixes following gcc warning:
error: ignoring return value of write, declared with attribute warn_unused_result

Change-Id: I96ea6649078449208a77690caea2cb237c388e6e
Signed-off-by: Spencer Oliver <spen@spen-soft.co.uk>
Reviewed-on: http://openocd.zylin.com/854
Tested-by: jenkins
Reviewed-by: Marc Reilly <marc@cpdesign.com.au>
Reviewed-by: Freddie Chopin <freddie.chopin@gmail.com>

diff --git a/src/jtag/drivers/sysfsgpio.c b/src/jtag/drivers/sysfsgpio.c
index 05d9a9dc0a248e3a17af34adba45dc394d1721d9..1cad268936547566f126cfa6ce2938fbcfecec80 100644 (file)
--- a/src/jtag/drivers/sysfsgpio.c
+++ b/src/jtag/drivers/sysfsgpio.c
@@ -199,6 +199,7 @@ static void sysfsgpio_write(int tck, int tms, int tdi)
        static int last_tdi;
 
        static int first_time;
+       size_t bytes_written;
 
        if (!first_time) {
                last_tck = !tck;
@@ -207,13 +208,24 @@ static void sysfsgpio_write(int tck, int tms, int tdi)
                first_time = 1;
        }
 
-       if (tdi != last_tdi)
-               write(tdi_fd, tdi ? &one : &zero, 1);
-       if (tms != last_tms)
-               write(tms_fd, tms ? &one : &zero, 1);
+       if (tdi != last_tdi) {
+               bytes_written = write(tdi_fd, tdi ? &one : &zero, 1);
+               if (bytes_written != 1)
+                       LOG_WARNING("writing tdi failed");
+       }
+
+       if (tms != last_tms) {
+               bytes_written = write(tms_fd, tms ? &one : &zero, 1);
+               if (bytes_written != 1)
+                       LOG_WARNING("writing tms failed");
+       }
+
        /* write clk last */
-       if (tck != last_tck)
-               write(tck_fd, tck ? &one : &zero, 1);
+       if (tck != last_tck) {
+               bytes_written = write(tck_fd, tck ? &one : &zero, 1);
+               if (bytes_written != 1)
+                       LOG_WARNING("writing tck failed");
+       }
 
        last_tdi = tdi;
        last_tms = tms;
@@ -229,14 +241,21 @@ static void sysfsgpio_reset(int trst, int srst)
 {
        const char one[] = "1";
        const char zero[] = "0";
+       size_t bytes_written;
 
        /* assume active low */
-       if (srst_fd >= 0)
-               write(srst_fd, srst ? &zero : &one, 1);
+       if (srst_fd >= 0) {
+               bytes_written = write(srst_fd, srst ? &zero : &one, 1);
+               if (bytes_written != 1)
+                       LOG_WARNING("writing srst failed");
+       }
 
        /* assume active low */
-       if (trst_fd >= 0)
-               write(trst_fd, trst ? &zero : &one, 1);
+       if (trst_fd >= 0) {
+               bytes_written = write(trst_fd, trst ? &zero : &one, 1);
+               if (bytes_written != 1)
+                       LOG_WARNING("writing trst failed");
+       }
 }
 
 /* No speed control is implemented yet */