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| author | N S <nlshipp@yahoo.com> | 2023-01-22 21:34:16 -0800 |
|---|---|---|
| committer | Antonio Borneo <borneo.antonio@gmail.com> | 2024-02-11 23:10:30 +0000 |
| commit | 7295ddc15c0516a64c9996d2b351accb50175803 (patch) | |
| tree | 887cf1f0f7d4b918b85c6a08e53861fb4dc7c1e4 | |
| parent | 81a50d3e9050eed8f4d95622f2b326054a200b93 (diff) | |
| download | riscv-openocd-7295ddc15c0516a64c9996d2b351accb50175803.zip riscv-openocd-7295ddc15c0516a64c9996d2b351accb50175803.tar.gz riscv-openocd-7295ddc15c0516a64c9996d2b351accb50175803.tar.bz2 | |
jtag/drivers: OpenJTAG standard variant perf improvement
Calculate exact size of response expected from OpenJTAG device so that
openjtag_buf_read_standard doesn't spend 5 retry cycles waiting for
data that isn't coming.
Change-Id: Icd010d1fa4453d6592a1f9aed93fb1f01e0a19da
Signed-off-by: N S <nlshipp@yahoo.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/8101
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
Tested-by: jenkins
| -rw-r--r-- | src/jtag/drivers/openjtag.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/src/jtag/drivers/openjtag.c b/src/jtag/drivers/openjtag.c index 45064fe..1c79a2c 100644 --- a/src/jtag/drivers/openjtag.c +++ b/src/jtag/drivers/openjtag.c @@ -530,9 +530,20 @@ static int openjtag_quit(void) static void openjtag_write_tap_buffer(void) { uint32_t written; + uint32_t rx_expected = 0; + + /* calculate expected number of return bytes */ + for (int tx_offs = 0; tx_offs < usb_tx_buf_offs; tx_offs++) { + if ((usb_tx_buf[tx_offs] & 0x0F) == 6) { + rx_expected++; + tx_offs++; + } else if ((usb_tx_buf[tx_offs] & 0x0F) == 2) { + rx_expected++; + } + } openjtag_buf_write(usb_tx_buf, usb_tx_buf_offs, &written); - openjtag_buf_read(usb_rx_buf, usb_tx_buf_offs, &usb_rx_buf_len); + openjtag_buf_read(usb_rx_buf, rx_expected, &usb_rx_buf_len); usb_tx_buf_offs = 0; } |