SPI transfer size >32 bytes corrupts memory and will likely hang the system

[dhendrix]

When transferring >32 bytes on SPI0 or SPI2, it seems to clobber memory and will likely crash the system. I noticed this when trying to use the SPI buses to read a flash chip using transfer size == 4096 bytes as per /sys/module/spidev/parameters/bufsiz. Using 32 bytes instead seems to work fine.

I am using the current TinkerOS image, Tinker_Board-Debian-Stretch-V2.1.11-20200310.img.

Using Linux's spidev_test tool (under linux/tools/spi), we can easily reproduce this behavior. Examples:

1. Transfer 32 bytes - We see the correct bytes on TX (16 a's followed by 16 b's in this example), and all 0xff's on RX as expected
   linaro@tb1:~/src/linux/tools/spi$ sudo ./spidev_test -v -D /dev/spidev0.0 -s 1000000 -i /tmp/in_32b.bin -o /tmp/out_32b.bin
   spi mode: 0x0
   bits per word: 8
   max speed: 1000000 Hz (1000 KHz)
   TX | 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 62 62 62 62 62 62 62 62 62 62 62 62 62 62 62 62 | aaaaaaaaaaaaaaaabbbbbbbbbbbbbbbb
   RX | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | ................................

2. Transfer 64 bytes - We see the correct bytes on TX (16 a's followed by 16 b's, 16 c's, and 16 d's). However, RX shows corruption immediately.
   linaro@tb1:~/src/linux/tools/spi$ sudo ./spidev_test -v -D /dev/spidev0.0 -s 1000000 -i /tmp/in_64b.bin -o /tmp/out_64b.bin
   spi mode: 0x0
   bits per word: 8
   max speed: 1000000 Hz (1000 KHz)
   TX | 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 62 62 62 62 62 62 62 62 62 62 62 62 62 62 62 62 | aaaaaaaaaaaaaaaabbbbbbbbbbbbbbbb
   TX | 63 63 63 63 63 63 63 63 63 63 63 63 63 63 63 63 64 64 64 64 64 64 64 64 64 64 64 64 64 64 64 64 | ccccccccccccccccdddddddddddddddd
   RX | FF 00 00 00 C6 88 DE BE 00 00 00 00 00 00 00 00 2F 74 6D 70 2F 72 61 6E 64 6F 6D 5F 36 34 62 5F | ....ƈ޾......../tmp/random_64b_
   RX | 6F 75 74 2E 62 69 6E 00 2F 6C 69 62 63 2E 73 6F 2E 36 00 00 2E 62 69 6E 00 6E 69 74 6F 72 65 2D | out.bin./libc.so.6...bin.nitore-

[ivbsd1]

Hi,
I have the same problem with Tinker Board running Debian:
Linux tinkerboard 4.4.132+ #1 SMP Wed Aug 21 19:15:55 CST 2019 armv7l GNU/Linux

Are there some updates about this SPI problem ? When fix expected ?
Maybe someone can suggest workaround ?
Thanks

[dcarlson27]

I just ran in to this. Can anyone share possible fix, or when spidev was updated to address this?

[yishinhung]

Hi @dcarlson27 :
Which image version do you use? I use the following image version and verify normally.

• Tinker Board S Debian 10 V3.0.11:

• Test by spidev_test tools
  root@linaro-alip:/home/linaro/Desktop/spidev-test# ./spidev_test -v -D /dev/spidev0.0 -s 1000000 -i ../in_64.bin -o out_64.bin
  spi mode: 0x0
  bits per word: 8
  max speed: 1000000 Hz (1000 KHz)
  TX | 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 62 62 62 62 62 62 62 62 62 62 62 62 62 62 62 62 | aaaaaaaaaaaaaaaabbbbbbbbbbbbbbbb
  TX | 63 63 63 63 63 63 63 63 63 63 63 63 63 63 63 63 64 64 64 64 64 64 64 64 64 64 64 64 64 64 64 64 | ccccccccccccccccdddddddddddddddd
  RX | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | ................................
  RX | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | ................................
  root@linaro-alip:/home/linaro/Desktop/spidev-test#
  root@linaro-alip:/home/linaro/Desktop/spidev-test# ./spidev_test -v -D /dev/spidev0.0 -s 1000000 -i ../in_32.bin -o out_32.bin
  spi mode: 0x0
  bits per word: 8
  max speed: 1000000 Hz (1000 KHz)
  TX | 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 62 62 62 62 62 62 62 62 62 62 62 62 62 62 62 62 | aaaaaaaaaaaaaaaabbbbbbbbbbbbbbbb
  RX | FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF | ................................