On 12/12/15 23:39, Andy Shevchenko wrote:
> On Wed, Dec 2, 2015 at 11:33 AM, Vladimir Murzin
> <vladimir.murzin@xxxxxxx> wrote:
>> This driver adds support to the UART controller found on ARM MPS2
>> platform.
>
> Just few comments (have neither time not big desire to do full review).
>
Still better than nothing ;) I'm mostly agree on points you had, so I've
just left some I'm doubt about...
>> +
>> +static void mps2_uart_enable_ms(struct uart_port *port)
>> +{
>> +}
>> +
>> +static void mps2_uart_break_ctl(struct uart_port *port, int ctl)
>> +{
>> +}
>
> Are those required to be present? If not, remove them until you have
> alive code there.
A quick grep shows that core calls mps2_uart_break_ctl()
unconditionally, but, yes, it checks for presence of
mps2_uart_enable_ms() before jumping there, so it is safe to remove latter.
>> +static irqreturn_t mps2_uart_oerrirq(int irq, void *data)
>> +{
>> + irqreturn_t handled = IRQ_NONE;
>> + struct uart_port *port = data;
>> + u8 irqflag = mps2_uart_read8(port, UARTn_INT);
>> +
>> + spin_lock(&port->lock);
>> +
>> + if (irqflag & UARTn_INT_RX_OVERRUN) {
>> + struct tty_port *tport = &port->state->port;
>> +
>> + mps2_uart_write8(port, UARTn_INT_RX_OVERRUN, UARTn_INT);
>> + tty_insert_flip_char(tport, 0, TTY_OVERRUN);
>> + port->icount.overrun++;
>> + handled = IRQ_HANDLED;
>> + }
>> +
>> + /* XXX: this shouldn't happen? */
>
> If shouldn't why it's there? Otherwise better to explain which
> conditions may lead to this.
>
In practice I've never seen that happened and I think it never *should*
happen since we check if there is room in TX buffer. However, I could be
wrong here, so it is why that statement has question mark.
>> + if (irqflag & UARTn_INT_TX_OVERRUN) {
>> + mps2_uart_write8(port, UARTn_INT_TX_OVERRUN, UARTn_INT);
>> + handled = IRQ_HANDLED;
>> + }
>> +
>> + spin_unlock(&port->lock);
>> +
>> + return handled;
>> +}
>> +
...
>> +static void mps2_uart_release_port(struct uart_port *port)
>> +{
>> +}
>> +
>> +static int mps2_uart_request_port(struct uart_port *port)
>> +{
>> + return 0;
>> +}
>> +
>
> Same question about empty stubs.
Looks like they called unconditionally by the core.
>> +static int __init mps2_uart_init(void)
>> +{
>> + int ret;
>> +
>> + ret = uart_register_driver(&mps2_uart_driver);
>> + if (ret)
>> + return ret;
>> +
>> + ret = platform_driver_register(&mps2_serial_driver);
>> + if (ret)
>> + uart_unregister_driver(&mps2_uart_driver);
>> +
>> + pr_info("MPS2 UART driver initialized\n");
>> +
>> + return ret;
>> +}
>> +module_init(mps2_uart_init);
>> +
>> +static void __exit mps2_uart_exit(void)
>> +{
>> + platform_driver_unregister(&mps2_serial_driver);
>> + uart_unregister_driver(&mps2_uart_driver);
>> +}
>> +module_exit(mps2_uart_exit);
>
> module_platform_driver();
> And move uart_*register calls to probe/remove.
>
With this move we'll get uart_*register for every device probed, no?
Thanks
Vladimir
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