This is a note to let you know that I've just added the patch titled spi: cadence-quadspi: fix incorrect supports_op() return value to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: spi-cadence-quadspi-fix-incorrect-supports_op-return.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit f56d18830151c1aa07a5d260a21f274bc0fa584f Author: Matthias Schiffer <matthias.schiffer@xxxxxxxxxxxxxxx> Date: Wed Apr 6 15:28:32 2022 +0200 spi: cadence-quadspi: fix incorrect supports_op() return value [ Upstream commit f1d388f216aeb41a5df518815ae559d14a6d438e ] Since the conversion to spi-mem, the driver advertised support for various operations that cqspi_set_protocol() was never expected to handle correctly - in particuar all non-DTR operations with command or address buswidth > 1. For DTR, all operations except for 8-8-8 would fail, as cqspi_set_protocol() returns -EINVAL. In non-DTR mode, this resulted in data corruption for SPI-NOR flashes that support such operations. As a minimal fix that can be backported to stable kernels, simply disallow the unsupported operations again to avoid this issue. Fixes: a314f6367787 ("mtd: spi-nor: Convert cadence-quadspi to use spi-mem framework") Signed-off-by: Matthias Schiffer <matthias.schiffer@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20220406132832.199777-1-matthias.schiffer@xxxxxxxxxxxxxxx Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c index 1a6294a06e72..75680eecd2f7 100644 --- a/drivers/spi/spi-cadence-quadspi.c +++ b/drivers/spi/spi-cadence-quadspi.c @@ -1226,9 +1226,24 @@ static bool cqspi_supports_mem_op(struct spi_mem *mem, all_false = !op->cmd.dtr && !op->addr.dtr && !op->dummy.dtr && !op->data.dtr; - /* Mixed DTR modes not supported. */ - if (!(all_true || all_false)) + if (all_true) { + /* Right now we only support 8-8-8 DTR mode. */ + if (op->cmd.nbytes && op->cmd.buswidth != 8) + return false; + if (op->addr.nbytes && op->addr.buswidth != 8) + return false; + if (op->data.nbytes && op->data.buswidth != 8) + return false; + } else if (all_false) { + /* Only 1-1-X ops are supported without DTR */ + if (op->cmd.nbytes && op->cmd.buswidth > 1) + return false; + if (op->addr.nbytes && op->addr.buswidth > 1) + return false; + } else { + /* Mixed DTR modes are not supported. */ return false; + } if (all_true) return spi_mem_dtr_supports_op(mem, op);