The commit dd11444327ce ("spi: dw-spi: Convert 16bit accesses to 32bit accesses") globally changed all register access in the dw_apb_ssi driver to 32 bit access, which breaks data register (FIFO) access on picoXcell platforms. This series introduces a boolean to the core spi-dw driver to indicate to the core that 16 bit data register access is appropriate, implements the code that respects that flag and updates the dw-spi-mmio driver to allow setting this boolean from the device tree. A binding documentation fix is included in this series. Prior to applying this change the following error presents on a picoCell pc3x3 platform: spi_master spi32766: interrupt_transfer: fifo overrun/underrun m25p80 spi32766.0: error -5 reading 9f m25p80: probe of spi32766.0 failed with error -5 With this series applied: m25p80 spi32766.0: m25p40 (512 Kbytes) Michael van der Westhuizen (2): dt: snps,dw-apb-ssi: Describe 16 bit data register usage limitations spi: dw: Allow interface drivers to limit data I/O to word sizes Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.txt | 3 +++ drivers/spi/spi-dw-mmio.c | 5 +++++ drivers/spi/spi-dw.c | 13 +++++++++++-- drivers/spi/spi-dw.h | 11 +++++++++++ 4 files changed, 30 insertions(+), 2 deletions(-) -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html