From f45d50ede6f9e6d76a218e6ed06cc352acad466f Mon Sep 17 00:00:00 2001 From: Michael Zaidman Date: Sat, 5 Nov 2022 23:11:39 +0200 Subject: HID: ft260: ft260_xfer_status routine cleanup After clarifying with FTDI's support, it turned out that the error condition (bit 1) in byte 1 of the i2c status HID report is a status bit reflecting all error conditions. When bits 2, 3, or 4 are raised to 1, bit 1 is set to 1 also. Since the ft260_xfer_status routine tests the error condition bit and exits in the case of an error, the program flow never reaches the conditional expressions for 2, 3, and 4 bits when any of them indicates an error state. Though these expressions are never evaluated to true, they are checked several times per IO, increasing the ft260_xfer_status polling cycle duration. The patch removes the conditional expressions for 2, 3, and 4 bits in byte 1 of the i2c status HID report. Signed-off-by: Michael Zaidman Tested-by: Guillaume Champagne Signed-off-by: Jiri Kosina --- drivers/hid/hid-ft260.c | 30 ++++++++++-------------------- 1 file changed, 10 insertions(+), 20 deletions(-) (limited to 'drivers/hid/hid-ft260.c') diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c index 79505c64dbfe..a35201d68b15 100644 --- a/drivers/hid/hid-ft260.c +++ b/drivers/hid/hid-ft260.c @@ -313,27 +313,17 @@ static int ft260_xfer_status(struct ft260_device *dev) if (report.bus_status & FT260_I2C_STATUS_CTRL_BUSY) return -EAGAIN; - if (report.bus_status & FT260_I2C_STATUS_BUS_BUSY) - return -EBUSY; - - if (report.bus_status & FT260_I2C_STATUS_ERROR) + /* + * The error condition (bit 1) is a status bit reflecting any + * error conditions. When any of the bits 2, 3, or 4 are raised + * to 1, bit 1 is also set to 1. + */ + if (report.bus_status & FT260_I2C_STATUS_ERROR) { + hid_err(hdev, "i2c bus error: %#02x\n", report.bus_status); return -EIO; + } - ret = -EIO; - - if (report.bus_status & FT260_I2C_STATUS_ADDR_NO_ACK) - ft260_dbg("unacknowledged address\n"); - - if (report.bus_status & FT260_I2C_STATUS_DATA_NO_ACK) - ft260_dbg("unacknowledged data\n"); - - if (report.bus_status & FT260_I2C_STATUS_ARBITR_LOST) - ft260_dbg("arbitration loss\n"); - - if (report.bus_status & FT260_I2C_STATUS_CTRL_IDLE) - ret = 0; - - return ret; + return 0; } static int ft260_hid_output_report(struct hid_device *hdev, u8 *data, @@ -376,7 +366,7 @@ static int ft260_hid_output_report_check_status(struct ft260_device *dev, break; } while (--try); - if (ret == 0 || ret == -EBUSY) + if (ret == 0) return 0; ft260_i2c_reset(hdev); -- cgit v1.2.3