From: Jamin Lin Date: Fri, 2 Jan 2026 09:07:45 +0000 (+0800) Subject: hw/i2c/aspeed: Fix wrong I2CC_DMA_LEN when I2CM_DMA_TX/RX_ADDR set first X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9cbd8ee7f67fceee51d3c993a282e5adc397b6b9;p=thirdparty%2Fqemu.git hw/i2c/aspeed: Fix wrong I2CC_DMA_LEN when I2CM_DMA_TX/RX_ADDR set first 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 Fixes: ba2cccd64e90 ("aspeed: i2c: Add new mode support") Reviewed-by: Cédric Le Goater Link: https://lore.kernel.org/qemu-devel/20260102090746.1130033-4-jamin_lin@aspeedtech.com Signed-off-by: Cédric Le Goater --- diff --git a/hw/i2c/aspeed_i2c.c b/hw/i2c/aspeed_i2c.c index faf2160c06..1b8ac561c3 100644 --- a/hw/i2c/aspeed_i2c.c +++ b/hw/i2c/aspeed_i2c.c @@ -656,8 +656,6 @@ 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, @@ -665,8 +663,6 @@ 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) || @@ -679,10 +675,16 @@ 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: