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| author | Michael Zaidman <michael.zaidman@gmail.com> | 2022-11-06 00:11:39 +0300 |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.cz> | 2022-11-11 13:09:35 +0300 |
| commit | f45d50ede6f9e6d76a218e6ed06cc352acad466f (patch) | |
| tree | 714a4c09729662cd277ec643e353c5301cfbb4d0 /drivers/hid/hid-ft260.c | |
| parent | 334fe5d3a99aea2e92b934b4c58fffee9b056c5d (diff) | |
| download | linux-f45d50ede6f9e6d76a218e6ed06cc352acad466f.tar.xz | |
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 <michael.zaidman@gmail.com>
Tested-by: Guillaume Champagne <champagne.guillaume.c@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'drivers/hid/hid-ft260.c')
| -rw-r--r-- | drivers/hid/hid-ft260.c | 30 |
1 files changed, 10 insertions, 20 deletions
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); |