diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-09-08 12:51:58 -0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-09-08 12:51:58 -0400 |
| commit | b1d27aa3b16a4689d5598abc545a88e5cda93f1d (patch) | |
| tree | a8684e6018b14686258770ad137d331b3f9f9322 | |
| parent | 26b1224903b3fb66e8aa564868d0d57648c32b15 (diff) | |
| parent | f5723cfc01932c7a8d5c78dbf7e067e537c91439 (diff) | |
Merge tag 'regmap-fix-v6.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap
Pull regmap fix from Mark Brown:
"A fix for how we handle controller constraints on SPI message sizes,
only impacting systems with SPI controllers with very low limits like
the AMD controller used in the Steam Deck"
* tag 'regmap-fix-v6.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
regmap: spi: Reserve space for register address/padding
| -rw-r--r-- | drivers/base/regmap/regmap-spi.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/base/regmap/regmap-spi.c b/drivers/base/regmap/regmap-spi.c index 719323bc6c7f..37ab23a9d034 100644 --- a/drivers/base/regmap/regmap-spi.c +++ b/drivers/base/regmap/regmap-spi.c @@ -113,6 +113,7 @@ static const struct regmap_bus *regmap_get_spi_bus(struct spi_device *spi, const struct regmap_config *config) { size_t max_size = spi_max_transfer_size(spi); + size_t max_msg_size, reg_reserve_size; struct regmap_bus *bus; if (max_size != SIZE_MAX) { @@ -120,9 +121,16 @@ static const struct regmap_bus *regmap_get_spi_bus(struct spi_device *spi, if (!bus) return ERR_PTR(-ENOMEM); + max_msg_size = spi_max_message_size(spi); + reg_reserve_size = config->reg_bits / BITS_PER_BYTE + + config->pad_bits / BITS_PER_BYTE; + if (max_size + reg_reserve_size > max_msg_size) + max_size -= reg_reserve_size; + bus->free_on_exit = true; bus->max_raw_read = max_size; bus->max_raw_write = max_size; + return bus; } |