git.sesse.net Git - nageru/blob - patches/bmusb-add-support-for-persistent-device-memory.diff

   1 diff --git a/bmusb.cpp b/bmusb.cpp
   2 index 2ea6407..16ec380 100644
   3 --- a/bmusb.cpp
   4 +++ b/bmusb.cpp
   5 @@ -1027,7 +1027,7 @@ void BMUSBCapture::configure_card()
   6         // set up isochronous transfers for audio and video
   7         for (int e = 3; e <= 4; ++e) {
   8                 //int num_transfers = (e == 3) ? 6 : 6;
   9 -               int num_transfers = 10;
  10 +               int num_transfers = 6;
  11                 for (int i = 0; i < num_transfers; ++i) {
  12                         size_t buf_size;
  13                         int num_iso_pack, size;
  14 @@ -1043,8 +1043,14 @@ void BMUSBCapture::configure_card()
  15                                 num_iso_pack = 80;
  16                                 buf_size = num_iso_pack * size;
  17                         }
  18 -                       assert(size_t(num_iso_pack * size) <= buf_size);
  19 -                       uint8_t *buf = new uint8_t[buf_size];
  20 +                       int num_bytes = num_iso_pack * size;
  21 +                       assert(size_t(num_bytes) <= buf_size);
  22 +                       uint8_t *buf = libusb_dev_mem_alloc(devh, num_bytes);
  23 +                       if (buf == nullptr) {
  24 +                               fprintf(stderr, "Failed to allocate persistent DMA memory (probably missing kernel patch).\n");
  25 +                               fprintf(stderr, "Will go slower, and likely fail due to memory fragmentation after a few hours.\n");
  26 +                               buf = new uint8_t[num_bytes];
  27 +                       }
  28
  29                         xfr = libusb_alloc_transfer(num_iso_pack);
  30                         if (!xfr) {