libffado/tests/test-cycle-time.c

   1 /*
   2  * Isochronous Cycle Timer register test
   3  *
   4  * Copyright 2010 Stefan Richter <stefanr@s5r6.in-berlin.de>
   5  * You may freely use, modify, and/or redistribute this program.
   6  *
   7  * Version imported into FFADO: v20100125, from
   8  *   http://user.in-berlin.de/~s5r6/linux1394/utils/
   9  *
  10  * This is a tool to test the reliability of one particular hardware feature
  11  * of OHCI-1394 (FireWire) controllers:  The isochronous cycle timer register.
  12  * Some controllers do not access this register atomically, resulting in the
  13  * cycle time seemingly jumping backwards occasionally.
  14  *
  15  * The firewire-ohci driver contains a workaround for unreliable isochronous
  16  * cycle timer hardware, but this workaround is only activated for known bad
  17  * hardware.  You can use this tool to check whether you have an affected
  18  * controller and firewire-ohci misses the necessary quirks entry.
  19  *
  20  * Usage:
  21  *
  22  *   - Compile with "gcc test_cycle_time_v20100125.c".
  23  *
  24  *   - Run with "sudo ./a.out /dev/fw0".  Use a different /dev/fw* file if you
  25  *     have multiple controllers in your machine and want to test the second
  26  *     or following controller.  Be patient, the test runs for 60 seconds.
  27  *
  28  *   - If the very last lines of the resulting output contains only
  29  *     "0 cycleOffset backwards", "0 cycleCount backwards", "0 cycleSeconds
  30  *     backwards", then either the hardware works correctly or the driver
  31  *     already uses the workaround to compensate for a cycle timer hardware
  32  *     bug.
  33  *     But if the last lines of the output show one or more of the three cycle
  34  *     timer components having gone backwards, then the hardware is buggy and
  35  *     the driver does not yet contain the necessary quirks entry.
  36  *
  37  * In the latter case, please report your findings at
  38  * <linux1394-devel@lists.sourceforge.net>.  This mailinglist is open for
  39  * posting without prior subscription.  Please include the type and identifiers
  40  * of your FireWire controller(s) in your posting, as obtained by "lspci -nn".
  41  *
  42  * Remark:
  43  *
  44  * This program optionally accesses /usr/share/misc/oui.db to translate the
  45  * Globally Unique Identifier of the device that is associated with the chosen
  46  * /dev/fw* to the company name of the device manufacturer.  The oui.db file
  47  * is not necessary for this program to work though.  If you want you can
  48  * generate oui.db this way:
  49  *     wget -O - http://standards.ieee.org/regauth/oui/oui.txt |
  50  *     grep -E '(base 16).*\w+.*$' |
  51  *     sed -e 's/\s*(base 16)\s*'/' /' > oui.db
  52  *     sudo mv oui.db /usr/share/misc/
  53  * which will download ~2 MB data and result in a ~0.4 MB large oui.db.
  54  */
  55
  56 #include <fcntl.h>
  57 #include <stdio.h>
  58 #include <stdlib.h>
  59 #include <sys/ioctl.h>
  60 #include <sys/stat.h>
  61 #include <sys/types.h>
  62 #include <unistd.h>
  63
  64 #include <linux/firewire-cdev.h>
  65
  66 #define TEST_DURATION 60 /* seconds */
  67
  68 static void cooked_ioctl(int fd, int req, void *arg, const char *name)
  69 {
  70         if (ioctl(fd, req, arg) < 0) {
  71                 fprintf(stderr, "Failed %s ioctl: %m\n", name);
  72                 exit(1);
  73         }
  74 }
  75
  76 static int rolled_over(__u32 c0, __u32 c1)
  77 {
  78         return  (c0 >> 25) == 127 &&
  79                 (c1 >> 25) == 0   &&
  80                 (c0 >> 12 & 0x1fff) > 8000 - 3 &&
  81                 (c1 >> 12 & 0x1fff) < 0000 + 3;
  82 }
  83
  84 static void print_ct(__u32 c, __u64 l)
  85 {
  86         printf("%03d %04d %04d - %lld.%06lld\n",
  87                c >> 25, c >> 12 & 0x1fff, c & 0xfff,
  88                l / 1000000, l % 1000000);
  89 }
  90
  91 int main(int argc, char **argv)
  92 {
  93         if (argc != 2) {
  94                 fprintf(stderr, "Usage: %s /dev/fw[0-n]*\n", argv[0]);
  95                 return -1;
  96         }
  97
  98         int fd = open(argv[1], O_RDWR);
  99         if (fd < 0) {
 100                 fprintf(stderr, "Failed to open %s: %m\n", argv[0]);
 101                 return -1;
 102         }
 103
 104         __u32 rom[4];
 105         struct fw_cdev_event_bus_reset reset;
 106         struct fw_cdev_get_info info = {
 107                 .rom            = (unsigned long)rom,
 108                 .rom_length     = sizeof(rom),
 109                 .bus_reset      = (unsigned long)&reset,
 110         };
 111         cooked_ioctl(fd, FW_CDEV_IOC_GET_INFO, &info, "info");
 112         if (reset.node_id != reset.local_node_id) {
 113                 fprintf(stderr, "Not a local node\n");
 114                 return -1;
 115         }
 116
 117         struct fw_cdev_get_cycle_timer ct;
 118         __u32 c0, c1;
 119         __u64 l0, l1, end_time;
 120         int i, j1, j2, j3;
 121         cooked_ioctl(fd, FW_CDEV_IOC_GET_CYCLE_TIMER, &ct, "cycle timer");
 122         c1 = ct.cycle_timer;
 123         l1 = ct.local_time;
 124         end_time = l1 + TEST_DURATION * 1000000ULL;
 125         for (i = j1 = j2 = j3 = 0; l1 < end_time; i++) {
 126                 cooked_ioctl(fd, FW_CDEV_IOC_GET_CYCLE_TIMER, &ct, "cycle timer");
 127                 c0 = c1;
 128                 l0 = l1;
 129                 c1 = ct.cycle_timer;
 130                 l1 = ct.local_time;
 131
 132                 if (c1 <= c0 && !rolled_over(c0, c1)) {
 133                         print_ct(c0, l0);
 134                         print_ct(c1, l1);
 135                         printf("\n");
 136                         j1++;
 137                         if ((c1 & 0xfffff000) < (c0 & 0xfffff000))
 138                                 j2++;
 139                         if ((c1 & 0xfe000000) < (c0 & 0xfe000000))
 140                                 j3++;
 141                 }
 142         }
 143
 144         printf("--------------------------------------------------------\n\n");
 145         fflush(stdout);
 146
 147         char buf[200];
 148         sprintf(buf, "grep %06X /usr/share/misc/oui.db", rom[3] >> 8);
 149         if (system(buf) != 0)
 150                 printf("%06X (unknown Vendor OUI)\n", rom[3] >> 8);
 151
 152         printf("\n%d cycleOffset backwards out of %d samples (%.2e)\n",
 153                j1, i, (double)j1 / (double)i);
 154
 155         printf("%d cycleCount backwards (%.2e)\n",
 156                j2, (double)j2 / (double)i);
 157
 158         printf("%d cycleSeconds backwards (%.2e)\n",
 159                j3, (double)j3 / (double)i);
 160
 161         return 0;
 162 }