I noticed i2c rx transfers were getting shortened to "1" on Zephyr. It seems to be because the Zephyr i2c driver sets the RX DMA len with the RX field write-enable bit set (bit 31) to avoid a read-modify-write. [1]
/* 0x1C : I2CM Master DMA Transfer Length Register */ I think we should be checking the write-enable bits on the incoming value, not checking the register array. I'm not sure we're even writing the write-enable bits to the register array, actually. [1] https://github.com/AspeedTech-BMC/zephyr/blob/db3dbcc9c52e67a47180890ac938ed380b33f91c/drivers/i2c/i2c_aspeed.c#L145-L148 Fixes: ba2cccd64e90f34 ("aspeed: i2c: Add new mode support") Signed-off-by: Peter Delevoryas <p...@fb.com> --- hw/i2c/aspeed_i2c.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/hw/i2c/aspeed_i2c.c b/hw/i2c/aspeed_i2c.c index ff33571954..cbaa7c96fc 100644 --- a/hw/i2c/aspeed_i2c.c +++ b/hw/i2c/aspeed_i2c.c @@ -644,18 +644,18 @@ static void aspeed_i2c_bus_new_write(AspeedI2CBus *bus, hwaddr offset, RX_BUF_LEN) + 1; break; case A_I2CM_DMA_LEN: - w1t = ARRAY_FIELD_EX32(bus->regs, I2CM_DMA_LEN, RX_BUF_LEN_W1T) || - ARRAY_FIELD_EX32(bus->regs, I2CM_DMA_LEN, TX_BUF_LEN_W1T); + w1t = FIELD_EX32(value, I2CM_DMA_LEN, RX_BUF_LEN_W1T) || + FIELD_EX32(value, I2CM_DMA_LEN, TX_BUF_LEN_W1T); /* If none of the w1t bits are set, just write to the reg as normal. */ if (!w1t) { bus->regs[R_I2CM_DMA_LEN] = value; break; } - if (ARRAY_FIELD_EX32(bus->regs, I2CM_DMA_LEN, RX_BUF_LEN_W1T)) { + if (FIELD_EX32(value, I2CM_DMA_LEN, RX_BUF_LEN_W1T)) { ARRAY_FIELD_DP32(bus->regs, I2CM_DMA_LEN, RX_BUF_LEN, FIELD_EX32(value, I2CM_DMA_LEN, RX_BUF_LEN)); } - if (ARRAY_FIELD_EX32(bus->regs, I2CM_DMA_LEN, TX_BUF_LEN_W1T)) { + if (FIELD_EX32(value, I2CM_DMA_LEN, TX_BUF_LEN_W1T)) { ARRAY_FIELD_DP32(bus->regs, I2CM_DMA_LEN, TX_BUF_LEN, FIELD_EX32(value, I2CM_DMA_LEN, TX_BUF_LEN)); } -- 2.30.2
