Messages in this thread Patch in this message | | | Date | Fri, 13 Dec 2019 12:50:33 +0200 | From | Andy Shevchenko <> | Subject | Re: [PATCH] drivers: tty: serial: 8250: fintek: Can enable or disable irq sharing based on isa or pci bus |
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On Fri, Dec 13, 2019 at 01:17:17PM +0800, chengang@emindsoft.com.cn wrote: > From: Chen Gang <chengang@emindsoft.com.cn>
Thanks for the patch, my comments below.
> Sorry for this patch being too late, which is for linux-next 20151127 ( > about linux 4.4-rc2). After 4 years, much things have been changed. But > I think it might be still valuable for some old versions. Welcome anyone > to refact this patch for their own.
This part should go after '---' line below.
> Fintek serial ports can share irq, but they need be enabled firstly, so > enable or disable irq sharing based on isa or pci bus. From kconfig, it
irq -> IRQ isa -> ISA pci -> PCI kconfig -> Kconfig
> can be configured. > > For integrated 8250 drivers, kernel always calls pnp driver, which will > not use integrated fintek driver for ever. So let pnp driver try the
fintek -> Fintek or Fintek 8250
> other drivers firstly (e.g. fintek), if fail, try pnp driver its own.
Ditto.
...
> --- a/drivers/tty/serial/8250/8250.h > +++ b/drivers/tty/serial/8250/8250.h > @@ -14,6 +14,7 @@ > #include <linux/serial_8250.h> > #include <linux/serial_reg.h> > #include <linux/dmaengine.h>
> +#include <linux/pnp.h>
The changes below doesn't require a header. Pointers are known to the compiler. Names of data structures can be forward declared. Moreover, these declarations may go inside respective #ifdef.
...
> +#if IS_ENABLED(CONFIG_SERIAL_8250_FINTEK_IRQ_SHARING) > + > +static void set_icsr(u16 base_port, u8 index) > +{ > + uint8_t icsr = 0; > + > + outb(LDN, base_port + ADDR_PORT); > + outb(index, base_port + DATA_PORT); > + outb(ICSR, base_port + ADDR_PORT); > + icsr = inb(base_port + DATA_PORT); > +
> + if (icsr != 0xff) {
if (icsr == 0xff) return;
?
> + icsr |= IRQ_SHARING_MOD; > +#if IS_ENABLED(CONFIG_SERIAL_8250_FINTEK_IRQ_SHARING_ISA) > + icsr |= ISA_IRQ_SHARING; > +#else > + icsr |= PCI_IRQ_SHARING; > +#endif > + outb(ICSR, base_port + ADDR_PORT); > + outb(icsr, base_port + DATA_PORT); > + } > +} > + > +#endif
...
> aux |= inb(addr[i] + DATA_PORT) << 8; > if (aux != io_address) > continue;
> -
What the point?
> +#if IS_ENABLED(CONFIG_SERIAL_8250_FINTEK_IRQ_SHARING) > + set_icsr(addr[i], k); > +#endif > fintek_8250_exit_key(addr[i]); > *key = keys[j]; > *index = k; > @@ -179,53 +212,6 @@ static int fintek_8250_base_port(u16 io_address, u8 *key, u8 *index) > return -ENODEV; > } > > -static int > -fintek_8250_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)
Why did you move this function? It's now not only hard to follow what has been changed, and to review.
> --- a/drivers/tty/serial/8250/8250_pnp.c > +++ b/drivers/tty/serial/8250/8250_pnp.c > @@ -438,8 +438,13 @@ static int > serial_pnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id) > { > struct uart_8250_port uart, *port; > - int ret, line, flags = dev_id->driver_data; > + int ret, line, flags; >
> +#if IS_BUILTIN(CONFIG_SERIAL_8250_FINTEK) > + if (!fintek_8250_probe(dev, dev_id)) > + return 0; > +#endif > + flags = dev_id->driver_data;
Oh, I don't like this. It needs a bit more refactoring done first.
The idea that we are not going to pollute generic driver(s) with quirks anymore (only when it's really unavoidable).
-- With Best Regards, Andy Shevchenko
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