On Mon 2019-09-02 11:32:39, Sakari Ailus wrote: > Add support for %pfw conversion specifier (with "f" and "P" modifiers) to > support printing full path of the node, including its name ("f") and only > the node's name ("P") in the printk family of functions. The two flags > have equivalent functionality to existing %pOF with the same two modifiers > ("f" and "P") on OF based systems. The ability to do the same on ACPI > based systems is added by this patch. > diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst > index 922a29eb70e6c..abba210f67567 100644 > --- a/Documentation/core-api/printk-formats.rst > +++ b/Documentation/core-api/printk-formats.rst > @@ -418,6 +418,30 @@ Examples:: > > Passed by reference. > > +Fwnode handles > +-------------- > + > +:: > + > + %pfw[fP] > + > +For printing information on fwnode handles. The default is to print the full > +node name, including the path. The modifiers are functionally equivalent to > +%pOF above. > + > + - f - full name of the node, including the path > + - P - the name of the node including an address (if there is one) > + > +Examples (ACPI): s/:/::/ for the .rst formar. > + > + %pfwf \_SB.PCI0.CIO2.port@1.endpoint@0 - Full node name > + %pfwP endpoint@0 - Node name > + > +Examples (OF): Same here. > + > + %pfwf /ocp@68000000/i2c@48072000/camera@10/port/endpoint - Full name > + %pfwP endpoint - Node name > + > Time and date (struct rtc_time) > ------------------------------- > > diff --git a/lib/vsprintf.c b/lib/vsprintf.c > index 4ad9332d54ba6..b9b4c835db063 100644 > --- a/lib/vsprintf.c > +++ b/lib/vsprintf.c > @@ -1981,6 +1981,36 @@ char *device_node_string(char *buf, char *end, struct device_node *dn, > return widen_string(buf, buf - buf_start, end, spec); > } > > +static noinline_for_stack > +char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode, > + struct printf_spec spec, const char *fmt) > +{ > + struct printf_spec str_spec = spec; > + char *buf_start = buf; > + > + str_spec.field_width = -1; > + > + if (*fmt != 'w') > + return error_string(buf, end, "(%pfw?)", spec); This means that only "%pfw" will dereference the pointer by fwnode_full_name_string() or fwnode_get_name(). All the other eventual misuses of the obsolete %pf format will result in this error message. OK, it is hard to imagine using "%pf" to get symbol name and always add 'w' suffix. Therefore it looks that reusing the obsolete %pf format modifier is pretty safe after all. > + if (check_pointer(&buf, end, fwnode, spec)) > + return buf; > + > + fmt++; > + > + switch (*fmt) { > + case 'f': /* full_name */ > + default: Using default: in the middle of switch might cause a lot of confusion. Please, make it the last label. > + buf = fwnode_full_name_string(fwnode, buf, end); > + break; > + case 'P': /* name */ > + buf = string(buf, end, fwnode_get_name(fwnode), str_spec); > + break; > + } > + > + return widen_string(buf, buf - buf_start, end, spec); > +} > + > /* > * Show a '%p' thing. A kernel extension is that the '%p' is followed > * by an extra set of alphanumeric characters that are extended format > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl > index a60c241112cd4..8df50911ff4e9 100755 > --- a/scripts/checkpatch.pl > +++ b/scripts/checkpatch.pl > @@ -5995,7 +5995,8 @@ sub process { > while ($fmt =~ /(\%[\*\d\.]*p(\w))/g) { > $specifier = $1; > $extension = $2; > - if ($extension !~ /[SsBKRraEhMmIiUDdgVCbGNOxt]/) { > + if ($extension !~ /[SsBKRraEhMmIiUDdgVCbGNOxtf]/ || > + $extension =~ /^f[^w]/) { This does not work. $extension seems to have only one character. Best Regards, Petr