On Thu, Aug 11, 2016 at 06:31:41PM +0300, Aleksey Makarov wrote: > +/** > + * pl011_console_match - non-standard console matching > + * @co: registering console > + * @name: name from console command line > + * @idx: index from console command line > + * @options: ptr to option string from console command line > + * > + * Only attempts to match console command lines of the form: > + * console=pl011,mmio|mmio32,<addr>[,<options>] > + * console=pl011,0x<addr>[,<options>] > + * This form is used to register an initial earlycon boot console and > + * replace it with the amba_console at pl011 driver init. > + * > + * Performs console setup for a match (as required by interface) > + * If no <options> are specified, then assume the h/w is already setup. > + * > + * Returns 0 if console matches; otherwise non-zero to use default matching > + */ > +static int __init pl011_console_match(struct console *co, char *name, int idx, > + char *options) > +{ > + char match[] = "pl011"; /* pl011-specific earlycon name */ This is inefficient - the compiler will probably store "pl011" in the rodata section, then allocate an array on the stack, and them memcpy() it onto the stack. This is really a false optimisation. > + unsigned char iotype; > + unsigned long addr; > + int i; > + > + if (strncmp(name, match, 5) != 0) Just do: if (strncmp(name, "pl011", 5) != 0) here, and let the compiler work it out - it'll probably place "pl011" in the rodata section, and use a pointer to it rather than messing around with the stack. What if "console=pl011x,..." is passed? Should this be matched too? Maybe this should compare with "pl011," to ensure that the name is correctly terminated? -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html