Some EC chip has larger flash sector size which requires longer erase time. During erase the CPU is usually stalled and can't even respond to interrupts. We sleep a while to block any EC command from executing during the flash erase period.
Signed-off-by: Wei-Ning Huang <[email protected]> --- drivers/mfd/cros_ec_i2c.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/drivers/mfd/cros_ec_i2c.c b/drivers/mfd/cros_ec_i2c.c index 9f70de1e4c70..8f23d5a8cc5b 100644 --- a/drivers/mfd/cros_ec_i2c.c +++ b/drivers/mfd/cros_ec_i2c.c @@ -23,6 +23,14 @@ #include <linux/platform_device.h> #include <linux/slab.h> +/* + * Some EC chip has larger flash sector size which requires longer erase time. + * During erase the CPU is usually stalled and can't even respond to + * interrupts. We sleep for a while to block any EC command from executing + * during the flash erase period to prevent i2c timeout. + */ +#define EC_FLASH_ERASE_DELAY_MS 5000 + /** * Request format for protocol v3 * byte 0 0xda (EC_COMMAND_PROTOCOL_3) @@ -177,6 +185,16 @@ static int cros_ec_pkt_xfer_i2c(struct cros_ec_device *ec_dev, ret = ec_response->data_len; + /* + * If we get EC_RES_IN_PROGRESS for EC_CMD_FLASH_ERASE this means EC + * need a long time to erase flash, during flash erase CPU is stalled + * and can't respond to interrupts, so we sleep for a while to stop new + * EC commands from communicating with EC. + */ + if (msg->command == EC_CMD_FLASH_ERASE && + msg->result == EC_RES_IN_PROGRESS) + msleep(EC_FLASH_ERASE_DELAY_MS); + done: if (msg->command == EC_CMD_REBOOT_EC) msleep(EC_REBOOT_DELAY_MS); -- 2.12.2
