This patch series includes two fixes for usb-serial. The first is a data corruption issue with xHCI controllers. The FTDI data packets need to have a 2 byte header start every 64 bytes of packet data. For EHCI this is not a problem since USBPacket size is 64, so only 1 such chunk fits in a packet. xHCI controllers supply 512 byte USBPackets, and usb-serial would only write a single header. This confuses drivers since they interpret some data bytes as header bytes. Chunk the data with headers at every 64 byte offset.
To allow full use of the 512 USBPackets, increase the buffer size to 512 - 2 * 8 = 496 bytes. A second fix is to set the FTDI_THRE (Transmitter Holding Register) and FTDI_TEMT (Transmitter Empty) status bits in a GetModemStat response. This makes the linux driver happy when closing the device and avoids a 30 second timeout. Jason Andryuk (4): usb-serial: Move USB_TOKEN_IN into a helper function usb-serial: chunk data to wMaxPacketSize usb-serial: Increase receive buffer to 496 usb-serial: Fix timeout closing the device hw/usb/dev-serial.c | 92 +++++++++++++++++++++++++++------------------ 1 file changed, 56 insertions(+), 36 deletions(-) -- 2.24.1
