On 09/12/2018 10:45 PM, Cédric Le Goater wrote [ ... ]
--- qemu: diff --git a/hw/i2c/aspeed_i2c.c b/hw/i2c/aspeed_i2c.c index c762c73..0d4aa08 100644 --- a/hw/i2c/aspeed_i2c.c +++ b/hw/i2c/aspeed_i2c.c @@ -180,6 +180,33 @@ static uint8_t aspeed_i2c_get_state(AspeedI2CBus *bus) return (bus->cmd >> I2CD_TX_STATE_SHIFT) & I2CD_TX_STATE_MASK; }+static void aspeed_i2c_handle_rx_cmd(AspeedI2CBus *bus)+{ + int ret; + + if (!(bus->cmd & (I2CD_M_RX_CMD | I2CD_M_S_RX_CMD_LAST))) { + return; + }it deserves a comment to understand which scenario we are trying to handle.+ if (bus->intr_status & I2CD_INTR_RX_DONE) { + return; + }should be handled in aspeed_i2c_bus_handle_cmd() I think
I moved those two checks into the calling code.
+ aspeed_i2c_set_state(bus, I2CD_MRXD); + ret = i2c_recv(bus->bus); + if (ret < 0) { + qemu_log_mask(LOG_GUEST_ERROR, "%s: read failed\n", __func__); + ret = 0xff; + } else { + bus->intr_status |= I2CD_INTR_RX_DONE; + } + bus->buf = (ret & I2CD_BYTE_BUF_RX_MASK) << I2CD_BYTE_BUF_RX_SHIFT; + if (bus->cmd & I2CD_M_S_RX_CMD_LAST) { + i2c_nack(bus->bus); + } + bus->cmd &= ~(I2CD_M_RX_CMD | I2CD_M_S_RX_CMD_LAST); + aspeed_i2c_set_state(bus, I2CD_MACTIVE); +} + /* * The state machine needs some refinement. It is only used to track * invalid STOP commands for the moment. @@ -188,7 +215,7 @@ static void aspeed_i2c_bus_handle_cmd(AspeedI2CBus *bus, uint64_t value) { bus->cmd &= ~0xFFFF; bus->cmd |= value & 0xFFFF; - bus->intr_status = 0;> + bus->intr_status &= I2CD_INTR_RX_DONE;it deserves a comment to understand which scenario we are trying to handle.
Ok. FWIW, I wonder if intr_status should be touched here in the first place, but I neither have the hardware nor a datasheet, so I don't know if any bits are auto-cleared.
if (bus->cmd & I2CD_M_START_CMD) { uint8_t state = aspeed_i2c_get_state(bus) & I2CD_MACTIVE ? @@ -227,22 +254,7 @@ static void aspeed_i2c_bus_handle_cmd(AspeedI2CBus *bus, uint64_t value) }if (bus->cmd & (I2CD_M_RX_CMD | I2CD_M_S_RX_CMD_LAST)) {- int ret; - - aspeed_i2c_set_state(bus, I2CD_MRXD); - ret = i2c_recv(bus->bus); - if (ret < 0) { - qemu_log_mask(LOG_GUEST_ERROR, "%s: read failed\n", __func__); - ret = 0xff; - } else { - bus->intr_status |= I2CD_INTR_RX_DONE; - } - bus->buf = (ret & I2CD_BYTE_BUF_RX_MASK) << I2CD_BYTE_BUF_RX_SHIFT; - if (bus->cmd & I2CD_M_S_RX_CMD_LAST) { - i2c_nack(bus->bus); - } - bus->cmd &= ~(I2CD_M_RX_CMD | I2CD_M_S_RX_CMD_LAST); - aspeed_i2c_set_state(bus, I2CD_MACTIVE); + aspeed_i2c_handle_rx_cmd(bus); }if (bus->cmd & I2CD_M_STOP_CMD) {@@ -263,6 +275,7 @@ static void aspeed_i2c_bus_write(void *opaque, hwaddr offset, uint64_t value, unsigned size) { AspeedI2CBus *bus = opaque; + int status;switch (offset) {case I2CD_FUN_CTRL_REG: @@ -283,9 +296,16 @@ static void aspeed_i2c_bus_write(void *opaque, hwaddr offset, bus->intr_ctrl = value & 0x7FFF; break; case I2CD_INTR_STS_REG: + status = bus->intr_status; bus->intr_status &= ~(value & 0x7FFF); - bus->controller->intr_status &= ~(1 << bus->id); - qemu_irq_lower(bus->controller->irq); + if (!bus->intr_status) { + bus->controller->intr_status &= ~(1 << bus->id); + qemu_irq_lower(bus->controller->irq); + }That part below is indeed something to fix. I had a similar patch.
Should I split it out as separate patch ? Alternatively, if you submitted your patch already, I'll be happy to use it as base for mine. Thanks, Guenter
+ if ((status & I2CD_INTR_RX_DONE) && !(bus->intr_status & I2CD_INTR_RX_DONE)) { + aspeed_i2c_handle_rx_cmd(bus); + aspeed_i2c_bus_raise_interrupt(bus); + }ok. Thanks for looking into this. C.break; case I2CD_DEV_ADDR_REG: qemu_log_mask(LOG_UNIMP, "%s: slave mode not implemented\n",
