spi: xilinx: Reversion detected on userspace SPI

["Alvaro G. M." <alvaro.gamez@xxxxxxxxxx>]

Hi

I've found that commit 5a1314fa697fc65cefaba64cd4699bfc3e6882a6 causes
userspace spi transfers to fail.

I've got a custom FPGA board with an Artix7 FPGA fitting a xilinx SPI core
attached to a Texas Instruments ADC. To configure this device I added a
compatible string on spidev.c and defined this device in the device tree,
so I get a /dev/spidev1.0 device.

A userspace application opens this device and performs SPI transfers using
the ioctl based interface.

When commit 5a1314fa697fc65cefaba64cd4699bfc3e6882a6 is applied, any write I
do is answered with the error message this patch introduces:

spidev spi1.0: Detected stall. Check C_SPI_MODE and C_SPI_MEMORY                       
spidev spi1.0: SPI transfer failed: -5                                                 
spi_master spi1: failed to transfer one message from queue                             

Reverting this commit restores things back and allows me to configure the ADC.

I can provide as much debug info as needed and can test whetever, but I
don't own a spi-nor flash that would trigger the error that Ricardo tried to
solve with his patch, so I couldn't test that my issue and his issue are
both solved simultaneously.

Best regards




-- 
Alvaro G. M.