[PATCH 5.13 022/127] spi: cadence-quadspi: Fix check condition for DTR ops

From: Sasha Levin
Date: Tue Aug 24 2021 - 12:57:22 EST


From: Apurva Nandan <a-nandan@xxxxxx>

[ Upstream commit 0395be967b067d99494113d78470574e86a02ed4 ]

buswidth and dtr fields in spi_mem_op are only valid when the
corresponding spi_mem_op phase has a non-zero length. For example,
SPI NAND core doesn't set buswidth when using SPI_MEM_OP_NO_ADDR
phase.

Fix the dtr checks in set_protocol() and suppports_mem_op() to
ignore empty spi_mem_op phases, as checking for dtr field in
empty phase will result in false negatives.

Signed-off-by: Apurva Nandan <a-nandan@xxxxxx>
Link: https://lore.kernel.org/r/20210716232504.182-3-a-nandan@xxxxxx
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/spi/spi-cadence-quadspi.c | 21 ++++++++++++++++++---
1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c
index d62d69dd72b9..73d4f0a1558d 100644
--- a/drivers/spi/spi-cadence-quadspi.c
+++ b/drivers/spi/spi-cadence-quadspi.c
@@ -325,7 +325,15 @@ static int cqspi_set_protocol(struct cqspi_flash_pdata *f_pdata,
f_pdata->inst_width = CQSPI_INST_TYPE_SINGLE;
f_pdata->addr_width = CQSPI_INST_TYPE_SINGLE;
f_pdata->data_width = CQSPI_INST_TYPE_SINGLE;
- f_pdata->dtr = op->data.dtr && op->cmd.dtr && op->addr.dtr;
+
+ /*
+ * For an op to be DTR, cmd phase along with every other non-empty
+ * phase should have dtr field set to 1. If an op phase has zero
+ * nbytes, ignore its dtr field; otherwise, check its dtr field.
+ */
+ f_pdata->dtr = op->cmd.dtr &&
+ (!op->addr.nbytes || op->addr.dtr) &&
+ (!op->data.nbytes || op->data.dtr);

switch (op->data.buswidth) {
case 0:
@@ -1227,8 +1235,15 @@ static bool cqspi_supports_mem_op(struct spi_mem *mem,
{
bool all_true, all_false;

- all_true = op->cmd.dtr && op->addr.dtr && op->dummy.dtr &&
- op->data.dtr;
+ /*
+ * op->dummy.dtr is required for converting nbytes into ncycles.
+ * Also, don't check the dtr field of the op phase having zero nbytes.
+ */
+ all_true = op->cmd.dtr &&
+ (!op->addr.nbytes || op->addr.dtr) &&
+ (!op->dummy.nbytes || op->dummy.dtr) &&
+ (!op->data.nbytes || op->data.dtr);
+
all_false = !op->cmd.dtr && !op->addr.dtr && !op->dummy.dtr &&
!op->data.dtr;

--
2.30.2