Messages in this thread | | | Date | Tue, 2 Jun 2009 19:21:18 -0400 | Subject | Re: [PATCH] tty: bfin_jtag_comm: emulate a TTY over the Blackfin EMUDAT/JTAG interface | From | Mike Frysinger <> |
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2009/6/2 Jiri Slaby <jirislaby@gmail.com>: > On 06/02/2009 09:25 PM, Mike Frysinger wrote: >> diff --git a/drivers/char/bfin_jtag_comm.c b/drivers/char/bfin_jtag_comm.c >> new file mode 100644 >> index 0000000..854f265 >> --- /dev/null >> +++ b/drivers/char/bfin_jtag_comm.c >> @@ -0,0 +1,365 @@ >> +#define pr_init(fmt, args...) ({ static const __initdata char __fmt[] = fmt; printk(__fmt, ## args); }) > > This should be __initconst.
looks like my earlier scan missed this driver, thanks
>> +#define debug(fmt, args...) pr_debug(DRV_NAME ": " fmt, ## args) > > Just define pr_fmt, instead of yet another debug macro.
i missed the new pr_fmt() macro addition
>> +static void >> +bfin_jc_wait_until_sent(struct tty_struct *tty, int timeout) >> +{ >> + unsigned long expire = jiffies + timeout; >> + while (!circ_empty(&bfin_jc_write_buf)) { >> + if (signal_pending(current)) >> + break; >> + if (time_after(jiffies, expire)) >> + break; > > Maybe some sort of sleep here?
i could add a schedule() call. the process has to stay running though because there is no async notification in the hardware that would be able to wake this guy up.
>> + } >> +} > > The tty handling is weird. You should take a reference before accessing > the structure.
tty documentation is non-existent. what reference exactly do you mean ? tty_driver_kref_get() and tty_driver_kref_put() ? no other tty driver uses that.
the tty handling is weird because of the hardware. we have to create a dedicated thread that constantly polls the hardware and this is all async to userspace accessing the tty. -mike -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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