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Merge pull request #586 from hathach/walkround-samd21-setup-overflow 

walkround for samd21 setup_packet overflow
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Ha Thach 2021-01-08 11:57:25 +07:00 committed by GitHub
parent 9f0b401f80 3e1d85eed2
commit 5442508f82
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1 changed files with 11 additions and 2 deletions
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13
src/portable/microchip/samd/dcd_samd.c
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@ -37,14 +37,23 @@
/* MACRO TYPEDEF CONSTANT ENUM
*------------------------------------------------------------------*/
static TU_ATTR_ALIGNED(4) UsbDeviceDescBank sram_registers[8][2];
static TU_ATTR_ALIGNED(4) uint8_t _setup_packet[8];
// Setup packet is only 8 bytes in length. However under certain scenario,
// USB DMA controller may decide to overwrite/overflow the buffer with
// 2 extra bytes of CRC. From datasheet's "Management of SETUP Transactions" section
// If the number of received data bytes is the maximum data payload specified by
// PCKSIZE.SIZE minus one, only the first CRC data is written to the data buffer.
// If the number of received data is equal or less than the data payload specified
// by PCKSIZE.SIZE minus two, both CRC data bytes are written to the data buffer.
// Therefore we will need to increase it to 10 bytes here.
static TU_ATTR_ALIGNED(4) uint8_t _setup_packet[8+2];
// ready for receiving SETUP packet
static inline void prepare_setup(void)
{
// Only make sure the EP0 OUT buffer is ready
sram_registers[0][0].ADDR.reg = (uint32_t) _setup_packet;
sram_registers[0][0].PCKSIZE.bit.MULTI_PACKET_SIZE = sizeof(_setup_packet);
sram_registers[0][0].PCKSIZE.bit.MULTI_PACKET_SIZE = sizeof(tusb_control_request_t);
sram_registers[0][0].PCKSIZE.bit.BYTE_COUNT = 0;
}