On Tue, Apr 16, 2024 at 08:55:34AM -0400, Parker Newman wrote:
> struct exar8250 {
> unsigned int nr;
> + unsigned int osc_freq;
> + struct pci_dev *pcidev;
> + struct device *dev;
Why do you need both a pci_dev and a device? Aren't they the same thing
here?
> +/**
> + * _cti_set_tristate() - Enable/Disable RS485 transciever tristate
> + * @priv: Device's private structure
> + * @port_num: Port number to set tristate on/off
> + * @enable: Enable tristate if true, disable if false
> + *
> + * Most RS485 capable cards have a power on tristate jumper/switch that ensures
> + * the RS422/RS485 transciever does not drive a multi-drop RS485 bus when it is
> + * not the master. When this jumper is installed the user must set the RS485
> + * mode to disable tristate prior to using the port.
> + *
> + * Some Exar UARTs have an auto-tristate feature while others require setting
> + * an MPIO to disable the tristate.
> + *
> + * Return: 0 on success, negative error code on failure
> + */
> +static int _cti_set_tristate(struct exar8250 *priv,
> + unsigned int port_num, bool enable)
> +{
> + int ret = 0;
> +
> + if (port_num >= priv->nr)
> + return -EINVAL;
> +
> + // Only Exar based cards use MPIO, return 0 otherwise
> + if (priv->pcidev->vendor != PCI_VENDOR_ID_EXAR)
> + return 0;
How can this ever happen? Only the exar devices will call this
function, or am I missing a path here?
> +
> + dev_dbg(priv->dev, "%s tristate for port %u\n",
> + str_enable_disable(enable), port_num);
> +
> + if (enable)
> + ret = exar_mpio_set_low(priv, port_num);
> + else
> + ret = exar_mpio_set_high(priv, port_num);
> + if (ret)
> + return ret;
> +
> + // Ensure MPIO is an output
> + ret = exar_mpio_config_output(priv, port_num);
> +
> + return ret;
> +}
> +
> +static int cti_tristate_disable(struct exar8250 *priv, unsigned int port_num)
> +{
> + return _cti_set_tristate(priv, port_num, false);
> +}
Do you ever call _cti_set_tristate() with "true"?
> +
> +/**
> + * _cti_set_plx_int_enable() - Enable/Disable PCI interrupts
> + * @priv: Device's private structure
> + * @enable: Enable interrupts if true, disable if false
But false is never used here, so why have this at all?
> + *
> + * Some older CTI cards require MPIO_0 to be set low to enable the PCI
> + * interupts from the UART to the PLX PCI->PCIe bridge.
> + *
> + * Return: 0 on success, negative error code on failure
> + */
> +static int _cti_set_plx_int_enable(struct exar8250 *priv, bool enable)
> +{
> + int ret = 0;
> +
> + // Only Exar based cards use MPIO, return 0 otherwise
> + if (priv->pcidev->vendor != PCI_VENDOR_ID_EXAR)
> + return 0;
Same question here.
> +
> + if (enable)
> + ret = exar_mpio_set_low(priv, 0);
> + else
> + ret = exar_mpio_set_high(priv, 0);
> + if (ret)
> + return ret;
> +
> + // Ensure MPIO is an output
> + ret = exar_mpio_config_output(priv, 0);
> +
> + return ret;
> +}
> +
> +static int cti_plx_int_enable(struct exar8250 *priv)
> +{
> + return _cti_set_plx_int_enable(priv, true);
Again, no wrapper needed if you never actually call that function with
"false", right? Or am I missing a path here?
thanks,
greg k-h
