From: Matthias Schiffer matthias.schiffer@ew.tq-group.com
[ 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@ew.tq-group.com Link: https://lore.kernel.org/r/20220406132832.199777-1-matthias.schiffer@ew.tq-gr... Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/spi/spi-cadence-quadspi.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-)
diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c index 75f356041138..b8ac24318cb3 100644 --- a/drivers/spi/spi-cadence-quadspi.c +++ b/drivers/spi/spi-cadence-quadspi.c @@ -1415,9 +1415,24 @@ 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);