@@ -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
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> --- drivers/spi/spi.c | 63 +++++++++++++++++++++++------------------------ 1 file changed, 31 insertions(+), 32 deletions(-)