Messages in this thread | | | Date | Wed, 14 Nov 2007 14:51:22 +0800 | From | "eric miao" <> | Subject | Re: [patch/rfc 1/4] GPIO implementation framework |
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On Nov 14, 2007 12:36 PM, David Brownell <david-b@pacbell.net> wrote: > On Tuesday 13 November 2007, eric miao wrote: > > Subject: [PATCH 5/5] move per GPIO "requested" to "struct gpio_desc" > > > > > struct gpio_desc { > > struct gpio_chip *chip; > > unsigned is_out:1; > > + unsigned requested:1; > > +#ifdef CONFIG_DEBUG_FS > > + const char *requested_str; > > +#endif > > A better name for this would be "label", matching what's > passed from gpio_request(). Ndls abrviatns r bd. >
Fine.
> > Note that this means (on typical 32-bit embedded hardware) > twelve bytes per GPIO, which if you assume 256 GPIOs means > an extra 3 KB static memory compared to the patch I sent. >
Note this reduces the memory in gpio_chip, so it consumes almost same memory as the patch you sent.
> > > @@ -43,20 +43,19 @@ static inline int gpio_is_onchip(unsigned gpio, > > struct gpio_chip *chip) > > /* Warn when drivers omit gpio_request() calls -- legal but > > * ill-advised when setting direction, and otherwise illegal. > > */ > > -static void gpio_ensure_requested(struct gpio_chip *chip, unsigned offset) > > +static void gpio_ensure_requested(unsigned gpio) > > Simpler to pass a gpio_desc pointer ... > > > > if (!requested) > > - printk(KERN_DEBUG "GPIO-%d autorequested\n", > > - chip->base + offset); > > + pr_debug("GPIO-%d autorequested\n", gpio); > > Leave the printk in ... this is the sort of thing we want > to see fixed, which becomes unlikely once you hide such > diagnostics. And for that matter, what would be enabling > the "-DDEBUG" that would trigger a pr_debug() message? >
line length issue, just ignore this if you prefer.
> > > ... overall the main downside of these patches seems to > be that it consumes more static memory. >
Not really, since it reduces the holes. That all depend on your ARCH_NR_GPIOS.
-- Cheers - eric - 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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