On Thu, Mar 23 2023, Dhruva Gole wrote:
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,
Right.
SPI NAND core doesn't set buswidth when using SPI_MEM_OP_NO_ADDR phase.
Fix the dtr checks in set_protocol() 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@ti.com Signed-off-by: Dhruva Gole d-gole@ti.com
drivers/spi/cadence_qspi.c | 11 +++++++++-- drivers/spi/cadence_qspi_apb.c | 9 ++++++++- 2 files changed, 17 insertions(+), 3 deletions(-)
diff --git a/drivers/spi/cadence_qspi.c b/drivers/spi/cadence_qspi.c index c7f10c501320..a858a62888e4 100644 --- a/drivers/spi/cadence_qspi.c +++ b/drivers/spi/cadence_qspi.c @@ -362,8 +362,15 @@ static bool cadence_spi_mem_supports_op(struct spi_slave *slave, { 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);
Looks good!
all_false = !op->cmd.dtr && !op->addr.dtr && !op->dummy.dtr && !op->data.dtr;
Since we treat DTR as "do not care" when the phase does not exist, you should check for that here as well. What if someone _sets_ DTR for a field with nbytes == 0? This check would fail.
Since no one reasonable should do this, I will not insist upon this. Fine by me if you don't do this. Your choice.
diff --git a/drivers/spi/cadence_qspi_apb.c b/drivers/spi/cadence_qspi_apb.c index 21fe2e655c5f..2b04b58124a5 100644 --- a/drivers/spi/cadence_qspi_apb.c +++ b/drivers/spi/cadence_qspi_apb.c @@ -120,7 +120,14 @@ static int cadence_qspi_set_protocol(struct cadence_spi_priv *priv, { int ret;
priv->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.*/priv->dtr = op->cmd.dtr &&(!op->addr.nbytes || op->addr.dtr) &&(!op->data.nbytes || op->data.dtr);
Why not check dummy? Since supports_op() already checks that _all_ or _none_ of the fields are DTR, you can get away with just checking for op->cmd.dtr here (do add a comment here or it can be a bit confusing).
BTW, I think it would be better if you get rid of cadence_qspi_set_protocol() entirely. I see no point in carrying the state around. Wherever you use priv->dtr or priv->inst_width, etc. you also have access to the spi_mem_op. You can derive that information from the op. Something to fix when you have some free time on your hands. Will make the driver a bit simpler.
ret = cadence_qspi_buswidth_to_inst_type(op->cmd.buswidth); if (ret < 0)-- 2.25.1