[PATCH 2/2] spi: cadence-quadspi: Fix check condition for DTR ops

[Apurva Nandan]

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>
---
 drivers/spi/spi-cadence-quadspi.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c
index a2e1f4ce8b3e..a884678e8dff 100644
--- a/drivers/spi/spi-cadence-quadspi.c
+++ b/drivers/spi/spi-cadence-quadspi.c
@@ -322,7 +322,9 @@ 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;
+	f_pdata->dtr = op->cmd.dtr &&
+		       (op->addr.dtr || !op->addr.nbytes) &&
+		       (op->data.dtr || !op->data.nbytes);
 
 	switch (op->data.buswidth) {
 	case 0:
@@ -1225,8 +1227,12 @@ 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 checked when converting nbytes into ncycles.*/
+	all_true = op->cmd.dtr &&
+		   (op->addr.dtr || !op->addr.nbytes) &&
+		   (op->dummy.dtr || !op->dummy.nbytes) &&
+		   (op->data.dtr || !op->data.nbytes);
+
 	all_false = !op->cmd.dtr && !op->addr.dtr && !op->dummy.dtr &&
 		    !op->data.dtr;
 
-- 
2.17.1