From: Joe Perches Subject: Re: [PATCH 3/4] of: Custom printk format specifier for device node Date: Thu, 15 Jun 2017 14:50:05 -0700 Message-ID: <1497563405.14396.17.camel@perches.com> References: <20170614203025.7581-1-robh@kernel.org> <20170614203025.7581-4-robh@kernel.org> <1497473808.18751.70.camel@perches.com> <20170615212616.2uakwphhphkdds4g@rob-hp-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170615212616.2uakwphhphkdds4g@rob-hp-laptop> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Rob Herring Cc: Frank Rowand , Mark Rutland , Pantelis Antoniou , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org On Thu, 2017-06-15 at 16:26 -0500, Rob Herring wrote: > On Wed, Jun 14, 2017 at 01:56:48PM -0700, Joe Perches wrote: > > On Wed, 2017-06-14 at 15:30 -0500, Rob Herring wrote: > > > From: Pantelis Antoniou [] > > > diff --git a/lib/vsprintf.c b/lib/vsprintf.c > > > [] > > > @@ -1470,6 +1471,123 @@ char *flags_string(char *buf, char *end, void *flags_ptr, const char *fmt) > > > return format_flags(buf, end, flags, names); > > > } > > > > > > +static noinline_for_stack > > > +char *device_node_gen_full_name(const struct device_node *np, char *buf, char *end) > > > +{ > > > + int len, ret; > > > + > > > + if (!np || !np->parent) > > > + return buf; > > > + > > > + buf = device_node_gen_full_name(np->parent, buf, end); > > > > This is recursive. How many levels of parents could there be? > > Perhaps there should be a recursion limit. > > Okay, unlike unflattening code, we can easily calculate the depth and > then allocate an array on the stack. So this is what I've ended up > with: > > static int device_node_calc_depth(const struct device_node *np) > { > int d; > > for (d = 0; np; d++) > np = np->parent; > > return d; > } > > static noinline_for_stack > char *device_node_gen_full_name(const struct device_node *np, char *buf, char *end) > { > int i; > int depth = device_node_calc_depth(np); > const struct device_node *nodes[depth]; > const struct printf_spec strspec = { > .field_width = -1, > .precision = -1, > }; static const struct printf_spec strspec = { etc... and please move strspec above *nodes > > if (!depth) > return buf; > /* special case for root node */ > if (depth == 1) > return string(buf, end, "/", strspec); > > depth--; > for (i = depth - 1; i >= 0; i--) { > nodes[i] = np; > np = np->parent; > } > for (i = 0; i < depth; i++) { > buf = string(buf, end, "/", strspec); > buf = string(buf, end, kbasename(nodes[i]->full_name), strspec); > } > return buf; > } -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html