mpsse: check available buffer space even for discarded data scans

When there's no data to scan in or out, we still use the clock data out
command and fill the buffer with zeroes, so make sure the buffer is
checked for available space.

Change-Id: Ia6005c40c81f7fdb89379f1b5023fe383184d210
Signed-off-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>
Reviewed-on: http://openocd.zylin.com/793
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>
Tested-by: jenkins
Reviewed-by: Freddie Chopin <freddie.chopin@gmail.com>

diff --git a/src/jtag/drivers/mpsse.c b/src/jtag/drivers/mpsse.c
index 063ef2ffb69bbf5fbd479105216e0e7802a72d4e..d6cbc8404c6e93330f3f38d6ed87317776b0e617 100644 (file)
--- a/src/jtag/drivers/mpsse.c
+++ b/src/jtag/drivers/mpsse.c
@@ -443,8 +443,8 @@ int mpsse_clock_data(struct mpsse_ctx *ctx, const uint8_t *out, unsigned out_off
 
        while (length > 0) {
                /* Guarantee buffer space enough for a minimum size transfer */
-               if (buffer_write_space(ctx) + (length < 8) < (out ? 4 : 3)
-                   || (in && buffer_read_space(ctx) < 1))
+               if (buffer_write_space(ctx) + (length < 8) < (out || (!out && !in) ? 4 : 3)
+                               || (in && buffer_read_space(ctx) < 1))
                        retval = mpsse_flush(ctx);
 
                if (length < 8) {
@@ -465,8 +465,8 @@ int mpsse_clock_data(struct mpsse_ctx *ctx, const uint8_t *out, unsigned out_off
                        if (this_bytes > 65536)
                                this_bytes = 65536;
                        /* Buffer space limit. We already made sure there's space for the minimum
-                        *transfer. */
-                       if (out && this_bytes + 3 > buffer_write_space(ctx))
+                        * transfer. */
+                       if ((out || (!out && !in)) && this_bytes + 3 > buffer_write_space(ctx))
                                this_bytes = buffer_write_space(ctx) - 3;
                        if (in && this_bytes > buffer_read_space(ctx))
                                this_bytes = buffer_read_space(ctx);