Hi Wolfram,
On 31/12/2019 16:13, Wolfram Sang wrote:
> There is a pattern to check for existence of a client which is copied in
> i2c_detect_address() and i2c_new_scanned_device():
>
> 1) check if address is valid
> 2) check if address is already registered
> 3) send a message and check the reponse
s/reponse/response/
(My email client highlights spelling issues, sorry :-D)
> Because this pattern will be needed a third time soon, refactor it into
> its own function.
This looks reasonable to me, I see Laurent has a concern over the use of
a WARN to present a backtrace, but I think in this instance it will be
useful as it will facilitate identifying what code path provided the
incorrect address.
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
>
> Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
> ---
> drivers/i2c/i2c-core-base.c | 57 ++++++++++++++++---------------------
> 1 file changed, 25 insertions(+), 32 deletions(-)
>
> diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
> index a1eb28a3cc54..20a726dc78db 100644
> --- a/drivers/i2c/i2c-core-base.c
> +++ b/drivers/i2c/i2c-core-base.c
> @@ -2108,29 +2108,39 @@ static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr)
> return err >= 0;
> }
>
> -static int i2c_detect_address(struct i2c_client *temp_client,
> - struct i2c_driver *driver)
> +static int i2c_scan_for_client(struct i2c_adapter *adap, unsigned short addr,
> + int (*probe)(struct i2c_adapter *adap, unsigned short addr))
> {
> - struct i2c_board_info info;
> - struct i2c_adapter *adapter = temp_client->adapter;
> - int addr = temp_client->addr;
> int err;
>
> /* Make sure the address is valid */
> err = i2c_check_7bit_addr_validity_strict(addr);
> - if (err) {
> - dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n",
> - addr);
> + if (WARN(err, "Invalid probe address 0x%02x\n", addr))
> return err;
> - }
>
> /* Skip if already in use (7 bit, no need to encode flags) */
> - if (i2c_check_addr_busy(adapter, addr))
> - return 0;
> + if (i2c_check_addr_busy(adap, addr))
> + return -EBUSY;
>
> /* Make sure there is something at this address */
> - if (!i2c_default_probe(adapter, addr))
> - return 0;
> + if (!probe(adap, addr))
> + return -ENODEV;
> +
> + return 0;
> +}
> +
> +static int i2c_detect_address(struct i2c_client *temp_client,
> + struct i2c_driver *driver)
> +{
> + struct i2c_board_info info;
> + struct i2c_adapter *adapter = temp_client->adapter;
> + int addr = temp_client->addr;
> + int err;
> +
> + /* Only report broken addresses, busy addresses are no error */
> + err = i2c_scan_for_client(adapter, addr, i2c_default_probe);
> + if (err < 0)
> + return err == -EINVAL ? -EINVAL : 0;
>
> /* Finally call the custom detection function */
> memset(&info, 0, sizeof(struct i2c_board_info));
> @@ -2232,26 +2242,9 @@ i2c_new_scanned_device(struct i2c_adapter *adap,
> if (!probe)
> probe = i2c_default_probe;
>
> - for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) {
> - /* Check address validity */
> - if (i2c_check_7bit_addr_validity_strict(addr_list[i]) < 0) {
> - dev_warn(&adap->dev, "Invalid 7-bit address 0x%02x\n",
> - addr_list[i]);
> - continue;
> - }
> -
> - /* Check address availability (7 bit, no need to encode flags) */
> - if (i2c_check_addr_busy(adap, addr_list[i])) {
> - dev_dbg(&adap->dev,
> - "Address 0x%02x already in use, not probing\n",
> - addr_list[i]);
> - continue;
> - }
> -
> - /* Test address responsiveness */
> - if (probe(adap, addr_list[i]))
> + for (i = 0; addr_list[i] != I2C_CLIENT_END; i++)
> + if (i2c_scan_for_client(adap, addr_list[i], probe) == 0)
> break;
> - }
>
> if (addr_list[i] == I2C_CLIENT_END) {
> dev_dbg(&adap->dev, "Probing failed, no device found\n");
>
