RE: [PATCH 1/2] drivers:staging:ti-st: move TI_ST from staging

Savoy, Pavan
2010-10-06T22:36:39Z

Jiri,

> -----Original Message-----
> From: Jiri Slaby [mailto:jirislaby@gmail.com]
> Sent: Wednesday, October 06, 2010 5:18 PM
> To: Savoy, Pavan
> Cc: gregkh@suse.de; linux-kernel@vger.kernel.org; devel@driverdev.osuosl.org;
> alan@lxorguk.ukuu.org.uk
> Subject: Re: [PATCH 1/2] drivers:staging:ti-st: move TI_ST from staging
>
> On 10/06/2010 10:08 PM, Savoy, Pavan wrote:
> >> On 10/06/2010 06:18 PM, pavan_savoy@ti.com wrote:
> >>> --- /dev/null
> >>> +++ b/drivers/misc/ti-st/st_core.c
> >>> @@ -0,0 +1,1031 @@
> >> ...
> >>> +#define PROTO_ENTRY(type, name) name
> >>> +const unsigned char *protocol_strngs[] = {
> >>> + PROTO_ENTRY(ST_BT, "Bluetooth"),
> >>> + PROTO_ENTRY(ST_FM, "FM"),
> >>> + PROTO_ENTRY(ST_GPS, "GPS"),
> >>> +};
> >>
> >> Is this planned to be used somewhere?
> >
> > Yes- would go in the debugfs.
> > Doesn't it already? Will check up, & will remove if not required.
>
> The thing probably is that you have protocol_strngs here and
> protocol_names there.
>
> >>> + pr_err("protocol %d not registered, no data to send?",
> >>> + protoid);
> >>
> >> Missing \n. And all over the code.
> >
> > With pr_fmt defined in each source file, the "\n" is not necessary.
> > I don't see the logs getting all jumbled up in one line.
> >
> > However If I don't have a pr_fmt, I see the need for "\n" - Please suggest.
>
> I can't explain that, but I see no reason why you wouldn't need \n
> there. It expands to standard printk(KERN_ERR "(stc): " fmt) where fmt
> should contain \n. I remember Linus sending a patch to the list which
> added \n by default if <.> is about to be printed next. But I don't know
> if he pushed it out. You can check printk implementation.
>
> >>> +static inline int st_check_data_len(struct st_data_s *st_gdata,
> >>
> >> It doesn't look like a candidate for inlining.
> >
> > Because?
>
> Because it does too much to be an inline. The compiler will inline that
> itself on its own if it decides to. It can count the pros and cons more
> precisely than we can. Also note that gcc will un-inline that if it
> decides to (if the inlining penalty is too high).
>
> >>> +int st_core_init(struct st_data_s **core_data)
> >>> +{
> >>> + struct st_data_s *st_gdata;
> >>> + long err;
> >>> + static struct tty_ldisc_ops *st_ldisc_ops;
> >>> +
> >>> + /* populate and register to TTY line discipline */
> >>> + st_ldisc_ops = kzalloc(sizeof(*st_ldisc_ops), GFP_KERNEL);
> >>> + if (!st_ldisc_ops) {
> >>> + pr_err("no mem to allocate");
> >>> + return -ENOMEM;
> >>> + }
> >>> +
> >>> + st_ldisc_ops->magic = TTY_LDISC_MAGIC;
> >>> + st_ldisc_ops->name = "n_st"; /*"n_hci"; */
> >>> + st_ldisc_ops->open = st_tty_open;
> >>> + st_ldisc_ops->close = st_tty_close;
> >>> + st_ldisc_ops->receive_buf = st_tty_receive;
> >>> + st_ldisc_ops->write_wakeup = st_tty_wakeup;
> >>> + st_ldisc_ops->flush_buffer = st_tty_flush_buffer;
> >>> + st_ldisc_ops->owner = THIS_MODULE;
> >>
> >> This can be static structure, you don't need to allocate this on heap.
> >> It should be a singleton.
> >
> > Yes, I got this comment before, but is it just a style issue?
> > I want to keep this in heap because some day, I hope TTY ldics have their
> own
> > private_data, which I can pass around like the tty_struct's data.
> > and having them in heap, I plan to keep a reference to ops structure, so
> that I
> > can pass around and use ops->private_data everywhere ..
>
> I doubt ldisc ops will ever have ->private_data. What would you need it
> for? The ops generally work with ttys which have ->disc_data.

Yes, But in this case, I required something which can be set during ldisc_register, and can be picked up during tty_open.

In any case, I will put up a patch for rest of the comments,
Thanks.

> >>> +void kim_int_recv(struct kim_data_s *kim_gdata,
> >>> + const unsigned char *data, long count)
> >>> +{
> >>> + register char *ptr;
> >>> + struct hci_event_hdr *eh;
> >>> + register int len = 0, type = 0;
> >>
> >> registers
> >>
> >>> + pr_debug("%s", __func__);
> >>
> >> \n
> >>
> >>> + /* Decode received bytes here */
> >>> + ptr = (char *)data;
> >>
> >> Casting from const to non-const. It doesn't look correct.
> >
> > So, would I rather declare ptr as const?
>
> Yes, if that makes sense. Otherwise de-const data.
>
> >>> +long st_kim_start(void *kim_data)
> >>> +{
> >>> + long err = 0;
> >>> + long retry = POR_RETRY_COUNT;
> >>> + struct kim_data_s *kim_gdata = (struct kim_data_s *)kim_data;
> >>> +
> >>> + pr_info(" %s", __func__);
> >>> +
> >>> + do {
> >>> + /* TODO: this is only because rfkill sub-system
> >>> + * doesn't send events to user-space if the state
> >>> + * isn't changed
> >>> + */
> >>> + rfkill_set_hw_state(kim_gdata->rfkill[ST_BT], 1);
> >>> + /* Configure BT nShutdown to HIGH state */
> >>> + gpio_set_value(kim_gdata->gpios[ST_BT], GPIO_LOW);
> >>> + mdelay(5); /* FIXME: a proper toggle */
> >>> + gpio_set_value(kim_gdata->gpios[ST_BT], GPIO_HIGH);
> >>> + mdelay(100);
> >>
> >> You can sleep here instead (below you wait for completion). 100 ms of
> >> busy waiting is way too much.
> >
> > It's agreed upon from the process, since it is in a process context.
> > Like's a device's open or hci0's UP.
>
> Dunno if you got me right. I meant mdelay->msleep.
>
> regards,
> --
> js