As suggested by Mike. Measurement showed a substantial performance gain As open/read/write/close is Posix it is still quite portable
Signed-off-by: Frans Meulenbroeks <[email protected]> --- We have discussed this before. The gain then seemed so small that it was not worthwhile, but a retest showed differently. Loading a 2.4 MB file in my board used to take between 1.58 and 1.59 min with this patch the same file takes between 1.12 and 1.13 min. Explanation why the previous test did not show improvement is slightly embarrasing. I'm testing on a different system than I develop, and I missed that urjtag has liburjtag to do the actual work. So initially I only copied over the jtag exe and not the libs, which of course gave no improvement as the exe was using the old libs with the old code. <blush> Frans. urjtag/src/tap/cable/gpio.c | 63 +++++++++++++++++++------------------------ 1 files changed, 28 insertions(+), 35 deletions(-) diff --git a/urjtag/src/tap/cable/gpio.c b/urjtag/src/tap/cable/gpio.c index b380dba..2d70946 100644 --- a/urjtag/src/tap/cable/gpio.c +++ b/urjtag/src/tap/cable/gpio.c @@ -56,7 +56,7 @@ typedef struct { unsigned int jtag_gpios[4]; int signals; uint32_t lastout; - FILE *fp_gpios[4]; + int fd_gpios[4]; } gpio_params_t; static int gpio_export (unsigned int gpio, int export) @@ -113,11 +113,12 @@ static int gpio_direction (unsigned int gpio, int out) return URJ_STATUS_OK; } -static int gpio_set_value (FILE *fp, int value) +static int gpio_set_value (int fd, int value) { - int ret; + ssize_t ret; + char gpio_value = value + '0'; - ret = fprintf (fp, "%u", value ? 1 : 0); + ret = write(fd, &gpio_value, 1); if (ret != 1) { urj_warning (_("Error setting value gpio\n")); @@ -127,13 +128,13 @@ static int gpio_set_value (FILE *fp, int value) return URJ_STATUS_OK; } -static int gpio_get_value (FILE *fp, unsigned int gpio) +static int gpio_get_value (int *fd, unsigned int gpio) { - int ret; - int value; + ssize_t ret; + char value; - fseek(fp, 0, 0); - ret = fscanf (fp, "%i", &value); + lseek(fd, 0, 0); + ret = read(fd, &value, 1); if (ret != 1) { @@ -141,7 +142,7 @@ static int gpio_get_value (FILE *fp, unsigned int gpio) return URJ_STATUS_FAIL; } - return value; + return value == '1'; } static int @@ -164,23 +165,15 @@ gpio_open (urj_cable_t *cable) } gpio_direction (gpio, (i == GPIO_TDO) ? 0 : 1); - p->fp_gpios[i] = NULL; + p->fd_gpios[i] = -1; snprintf (fname, sizeof (fname), "%sgpio%u/value", GPIO_PATH, gpio); fname[sizeof (fname) - 1] = '\0'; - if (i != GPIO_TDO) - p->fp_gpios[i] = fopen (fname, "w"); - else - p->fp_gpios[i] = fopen (fname, "r"); - if (!p->fp_gpios[i]) + p->fd_gpios[i] = open (fname, O_RDWR); + if (p->fd_gpios[i] < 0) { urj_warning (_("%s: cannot open gpio[%d] %u\n"), fname, i, gpio); return URJ_STATUS_FAIL; } - if (setvbuf(p->fp_gpios[i], (char *)NULL, _IONBF, 0)) - { - urj_warning (_("gpio[%d] %u still in buffered mode\n"), i, gpio); - return URJ_STATUS_FAIL; - } } return URJ_STATUS_OK; @@ -194,8 +187,8 @@ gpio_close (urj_cable_t *cable) for (i = 0; i < GPIO_REQUIRED; i++) { - if (p->fp_gpios[i]) - fclose (p->fp_gpios[i]); + if (p->fd_gpios[i]) + close (p->fd_gpios[i]); gpio_export (p->jtag_gpios[i], 0); } @@ -319,14 +312,14 @@ gpio_clock (urj_cable_t *cable, int tms, int tdi, int n) tms = tms ? 1 : 0; tdi = tdi ? 1 : 0; - gpio_set_value (p->fp_gpios[GPIO_TMS], tms); - gpio_set_value (p->fp_gpios[GPIO_TDI], tdi); + gpio_set_value (p->fd_gpios[GPIO_TMS], tms); + gpio_set_value (p->fd_gpios[GPIO_TDI], tdi); for (i = 0; i < n; i++) { - gpio_set_value (p->fp_gpios[GPIO_TCK], 0); - gpio_set_value (p->fp_gpios[GPIO_TCK], 1); - gpio_set_value (p->fp_gpios[GPIO_TCK], 0); + gpio_set_value (p->fd_gpios[GPIO_TCK], 0); + gpio_set_value (p->fd_gpios[GPIO_TCK], 1); + gpio_set_value (p->fd_gpios[GPIO_TCK], 0); } } @@ -335,14 +328,14 @@ gpio_get_tdo ( urj_cable_t *cable ) { gpio_params_t *p = cable->params; - gpio_set_value(p->fp_gpios[GPIO_TCK], 0); - gpio_set_value(p->fp_gpios[GPIO_TDI], 0); - gpio_set_value(p->fp_gpios[GPIO_TMS], 0); + gpio_set_value(p->fd_gpios[GPIO_TCK], 0); + gpio_set_value(p->fd_gpios[GPIO_TDI], 0); + gpio_set_value(p->fd_gpios[GPIO_TMS], 0); p->lastout &= ~(URJ_POD_CS_TMS | URJ_POD_CS_TDI | URJ_POD_CS_TCK); urj_tap_cable_wait (cable); - return gpio_get_value (p->fp_gpios[GPIO_TDO], p->jtag_gpios[GPIO_TDO]); + return gpio_get_value (p->fd_gpios[GPIO_TDO], p->jtag_gpios[GPIO_TDO]); } static int @@ -370,11 +363,11 @@ gpio_set_signal (urj_cable_t *cable, int mask, int val) if (mask != 0) { if (mask & URJ_POD_CS_TMS) - gpio_set_value (p->fp_gpios[GPIO_TMS], val & URJ_POD_CS_TMS); + gpio_set_value (p->fd_gpios[GPIO_TMS], val & URJ_POD_CS_TMS); if (mask & URJ_POD_CS_TDI) - gpio_set_value (p->fp_gpios[GPIO_TDI], val & URJ_POD_CS_TDI); + gpio_set_value (p->fd_gpios[GPIO_TDI], val & URJ_POD_CS_TDI); if (mask & URJ_POD_CS_TCK) - gpio_set_value (p->fp_gpios[GPIO_TCK], val & URJ_POD_CS_TCK); + gpio_set_value (p->fd_gpios[GPIO_TCK], val & URJ_POD_CS_TCK); } p->lastout = val & mask; -- 1.7.0.4 ------------------------------------------------------------------------------ Sell apps to millions through the Intel(R) Atom(Tm) Developer Program Be part of this innovative community and reach millions of netbook users worldwide. 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