diff options
| author | Felix Held <felix-coreboot@felixheld.de> | 2021-12-10 18:38:16 +0100 |
|---|---|---|
| committer | Felix Held <felix-coreboot@felixheld.de> | 2021-12-15 22:39:21 +0000 |
| commit | 55dce1d55df554e684c87ab1baea9edfcb12aa09 (patch) | |
| tree | d779575821c070f50f18abdacea1c446ff433b9c | |
| parent | e3ae755575e0646f9dd47400a1dfc6018e16e9a8 (diff) | |
drivers/spi/spi-generic: document SPI_CNTRLR_DEDUCT_CMD_LEN better
This should make it a bit clearer what the differences between
SPI_CNTRLR_DEDUCT_OPCODE_LEN and SPI_CNTRLR_DEDUCT_CMD_LEN and the
corresponding functionality in spi_crop_chunk are.
Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: I809adebb182fc0866b93372b5b486117176da388
Reviewed-on: https://review.coreboot.org/c/coreboot/+/60122
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Raul Rangel <rrangel@chromium.org>
| -rw-r--r-- | src/drivers/spi/spi-generic.c | 4 | ||||
| -rw-r--r-- | src/include/spi-generic.h | 3 |
2 files changed, 6 insertions, 1 deletions
diff --git a/src/drivers/spi/spi-generic.c b/src/drivers/spi/spi-generic.c index 9796663da2..e6ec7bd8d5 100644 --- a/src/drivers/spi/spi-generic.c +++ b/src/drivers/spi/spi-generic.c @@ -98,6 +98,10 @@ unsigned int spi_crop_chunk(const struct spi_slave *slave, unsigned int cmd_len, if (deduct_opcode_len) cmd_len--; + /* Subtract command length from useable buffer size. If + deduct_opcode_len is set, only subtract the number command bytes + after the opcode. If the adjusted cmd_len is larger than ctrlr_max + return 0 to inidicate an error. */ if (deduct_cmd_len) { if (ctrlr_max >= cmd_len) { ctrlr_max -= cmd_len; diff --git a/src/include/spi-generic.h b/src/include/spi-generic.h index 77a3c09a79..acb22ec1d2 100644 --- a/src/include/spi-generic.h +++ b/src/include/spi-generic.h @@ -111,7 +111,8 @@ enum ctrlr_prot_type { enum { /* Deduct the command length from the spi_crop_chunk() calculation for - sizing a transaction. */ + sizing a transaction. If SPI_CNTRLR_DEDUCT_OPCODE_LEN is set, only + the bytes after the command byte will be deducted. */ SPI_CNTRLR_DEDUCT_CMD_LEN = 1 << 0, /* Remove the opcode size from the command length used in the spi_crop_chunk() calculation. Controllers which have a dedicated |