From b03ff2a23359d0dd6f0a1516c6a9e9c4760ed230 Mon Sep 17 00:00:00 2001 From: Sowjanya Komatineni Date: Tue, 12 Feb 2019 11:06:45 -0800 Subject: i2c: tegra: update maximum transfer size Tegra194 supports maximum 64K bytes per packet including 12 bytes of packet header irrespective of PIO or DMA mode transfer. This patch updates Tegra194 max write length to account for packet header size for transfers. Cc: stable@vger.kernel.org # 4.20+ Reviewed-by: Dmitry Osipenko Signed-off-by: Sowjanya Komatineni Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-tegra.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c index 036cab795426..f8265bd5d02c 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. @@ -900,12 +903,13 @@ 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 - 12, + .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 struct i2c_bus_recovery_info tegra_i2c_recovery_info = { -- cgit