From: David Lechner dlechner@baylibre.com
[ Upstream commit c8bec3355f08ddb887d5c13b7095dfa79e6db108 ]
This moves splitting transfers for CS_WORD software emulation to the same place where we split transfers for controller-specific reasons.
This fixes a few subtle bugs.
The calculation for maxsize was wrong for bit sizes between 17 and 24. This is fixed by making use of spi_split_transfers_maxwords() which already has the correct calculation.
Also, since this indirectly calls spi_res_alloc(), to avoid leaking resources, spi_finalize_current_message() would need to be called on all error paths in __spi_validate() and callers of __spi_validate() would need to do the same. This is fixed by moving the call to __spi_pump_transfer_message() where it is already splitting transfers for other reasons and correctly releases resources in the subsequent error paths.
Fixes: cbaa62e0094a ("spi: add software implementation for SPI_CS_WORD") Signed-off-by: David Lechner dlechner@baylibre.com Link: https://lore.kernel.org/r/20240126212358.3916280-2-dlechner@baylibre.com Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/spi/spi.c | 63 +++++++++++++++++++++++------------------------ 1 file changed, 31 insertions(+), 32 deletions(-)
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 8dfe635fffd63..d1b297f438f14 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1747,13 +1747,37 @@ static int __spi_pump_transfer_message(struct spi_controller *ctlr,
trace_spi_message_start(msg);
- ret = spi_split_transfers_maxsize(ctlr, msg, - spi_max_transfer_size(msg->spi), - GFP_KERNEL | GFP_DMA); - if (ret) { - msg->status = ret; - spi_finalize_current_message(ctlr); - return ret; + /* + * If an SPI controller does not support toggling the CS line on each + * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO + * for the CS line, we can emulate the CS-per-word hardware function by + * splitting transfers into one-word transfers and ensuring that + * cs_change is set for each transfer. + */ + if ((msg->spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) || + spi_is_csgpiod(msg->spi))) { + ret = spi_split_transfers_maxwords(ctlr, msg, 1, GFP_KERNEL); + if (ret) { + msg->status = ret; + spi_finalize_current_message(ctlr); + return ret; + } + + list_for_each_entry(xfer, &msg->transfers, transfer_list) { + /* Don't change cs_change on the last entry in the list */ + if (list_is_last(&xfer->transfer_list, &msg->transfers)) + break; + xfer->cs_change = 1; + } + } else { + ret = spi_split_transfers_maxsize(ctlr, msg, + spi_max_transfer_size(msg->spi), + GFP_KERNEL | GFP_DMA); + if (ret) { + msg->status = ret; + spi_finalize_current_message(ctlr); + return ret; + } }
if (ctlr->prepare_message) { @@ -4065,31 +4089,6 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message)
message->spi = spi;
- /* - * If an SPI controller does not support toggling the CS line on each - * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO - * for the CS line, we can emulate the CS-per-word hardware function by - * splitting transfers into one-word transfers and ensuring that - * cs_change is set for each transfer. - */ - if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) || - spi_is_csgpiod(spi))) { - size_t maxsize = BITS_TO_BYTES(spi->bits_per_word); - int ret; - - ret = spi_split_transfers_maxsize(ctlr, message, maxsize, - GFP_KERNEL); - if (ret) - return ret; - - list_for_each_entry(xfer, &message->transfers, transfer_list) { - /* Don't change cs_change on the last entry in the list */ - if (list_is_last(&xfer->transfer_list, &message->transfers)) - break; - xfer->cs_change = 1; - } - } - /* * Half-duplex links include original MicroWire, and ones with * only one data pin like SPI_3WIRE (switches direction) or where