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hw/i2c/aspeed: Fix wrong I2CC_DMA_LEN when I2CM_DMA_TX/RX_ADDR set first

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In the previous design, the I2C model would update I2CC_DMA_LEN (0x54) based on
the value of I2CM_DMA_LEN (0x1C) when the firmware set either I2CM_DMA_TX_ADDR
(0x30) or I2CM_DMA_RX_ADDR (0x34). However, this only worked correctly if the
firmware set I2CM_DMA_LEN before setting I2CM_DMA_TX_ADDR or I2CM_DMA_RX_ADDR.

If the firmware instead set I2CM_DMA_TX_ADDR or I2CM_DMA_RX_ADDR before setting
I2CM_DMA_LEN, the value written to I2CC_DMA_LEN would be incorrect.

To fix this issue, the model should be updated to set I2CC_DMA_LEN when the
firmware writes to the I2CM_DMA_LEN register, rather than when it writes to the
I2CM_DMA_RX_ADDR and I2CM_DMA_TX_ADDR registers.

Signed-off-by: Jamin Lin <jamin_lin@aspeedtech.com>
Fixes: ba2cccd64e ("aspeed: i2c: Add new mode support")
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/qemu-devel/20260102090746.1130033-4-jamin_lin@aspeedtech.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>
(cherry picked from commit 9cbd8ee7f67fceee51d3c993a282e5adc397b6b9)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
This commit is contained in:
Jamin Lin 2026-01-02 17:07:45 +08:00 • committed by Michael Tokarev
parent 146214796c
commit a66c02ea9d
1 changed files with 6 additions and 4 deletions
Download patch file Download diff file Expand all files Collapse all files

10
hw/i2c/aspeed_i2c.c
View file

@ -660,8 +660,6 @@ static void aspeed_i2c_bus_new_write(AspeedI2CBus *bus, hwaddr offset,
bus->dma_dram_offset =
deposit64(bus->dma_dram_offset, 0, 32,
FIELD_EX32(value, I2CM_DMA_TX_ADDR, ADDR));
bus->regs[R_I2CC_DMA_LEN] = ARRAY_FIELD_EX32(bus->regs, I2CM_DMA_LEN,
TX_BUF_LEN) + 1;
break;
case A_I2CM_DMA_RX_ADDR:
bus->regs[R_I2CM_DMA_RX_ADDR] = FIELD_EX32(value, I2CM_DMA_RX_ADDR,
@ -669,8 +667,6 @@ static void aspeed_i2c_bus_new_write(AspeedI2CBus *bus, hwaddr offset,
bus->dma_dram_offset =
deposit64(bus->dma_dram_offset, 0, 32,
FIELD_EX32(value, I2CM_DMA_RX_ADDR, ADDR));
bus->regs[R_I2CC_DMA_LEN] = ARRAY_FIELD_EX32(bus->regs, I2CM_DMA_LEN,
RX_BUF_LEN) + 1;
break;
case A_I2CM_DMA_LEN:
w1t = FIELD_EX32(value, I2CM_DMA_LEN, RX_BUF_LEN_W1T) ||
@ -683,10 +679,16 @@ static void aspeed_i2c_bus_new_write(AspeedI2CBus *bus, hwaddr offset,
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));
bus->regs[R_I2CC_DMA_LEN] = ARRAY_FIELD_EX32(bus->regs,
I2CM_DMA_LEN,
RX_BUF_LEN) + 1;
}
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));
bus->regs[R_I2CC_DMA_LEN] = ARRAY_FIELD_EX32(bus->regs,
I2CM_DMA_LEN,
TX_BUF_LEN) + 1;
}
break;
case A_I2CM_DMA_LEN_STS: