Tegra194 supports maximum 64K bytes transfer per packet. Tegra186 and prior supports maximum 4K bytes transfer per packet. This includes 12 bytes of packet header and this limit is applicable irrespective of PIO or DMA mode transfers.
This patch fixes max write length to account for packet header size for transfers.
Cc: stable@vger.kernel.org
Reviewed-by: Dmitry Osipenko digetx@gmail.com Signed-off-by: Sowjanya Komatineni skomatineni@nvidia.com --- [V18] : Using Max of SZ_64K (65536) size for dma buffer instead of 65535 [V16/V17] : I2C core max message size is 65535. So, max_read_len of 65535 is NOP. Removed it leaving max_write_len [V15] : This is new patch in this series.
drivers/i2c/busses/i2c-tegra.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c index 3758c7a2c781..08bdefd2810e 100644 --- a/drivers/i2c/busses/i2c-tegra.c +++ b/drivers/i2c/busses/i2c-tegra.c @@ -125,6 +125,9 @@ #define I2C_MST_FIFO_STATUS_TX_MASK 0xff0000 #define I2C_MST_FIFO_STATUS_TX_SHIFT 16
+/* Packet header size in bytes */ +#define I2C_PACKET_HEADER_SIZE 12 + /* * msg_end_type: The bus control which need to be send at end of transfer. * @MSG_END_STOP: Send stop pulse at end of transfer. @@ -899,12 +902,13 @@ static const struct i2c_algorithm tegra_i2c_algo = { /* payload size is only 12 bit */ static const struct i2c_adapter_quirks tegra_i2c_quirks = { .flags = I2C_AQ_NO_ZERO_LEN, - .max_read_len = 4096, - .max_write_len = 4096, + .max_read_len = SZ_4K, + .max_write_len = SZ_4K - I2C_PACKET_HEADER_SIZE, };
static const struct i2c_adapter_quirks tegra194_i2c_quirks = { .flags = I2C_AQ_NO_ZERO_LEN, + .max_write_len = SZ_64K - I2C_PACKET_HEADER_SIZE, };
static const struct tegra_i2c_hw_feature tegra20_i2c_hw = {