Previously zero length transfers submitted to the Rokchip SPI driver would
time out in the SPI layer. This happens because the SPI peripheral does
not trigger a transfer completion interrupt for zero length transfers.
Fix that by completing zero length transfers immediately at start of
transfer.
Signed-off-by: Tobias Schramm <t.schramm@manjaro.org>
Link: https://lore.kernel.org/r/20210827050357.165409-1-t.schramm@manjaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
int ret;
bool use_dma;
+ /* Zero length transfers won't trigger an interrupt on completion */
+ if (!xfer->len) {
+ spi_finalize_current_transfer(ctlr);
+ return 1;
+ }
+
WARN_ON(readl_relaxed(rs->regs + ROCKCHIP_SPI_SSIENR) &&
(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY));