Peter Hurley, First of all, thank you for your reviewing. Please see my answers below.
On Tue, May 26, 2015 at 01:12:34PM -0400, Peter Hurley wrote: > Hi Bin, > > Please don't drop lists (or other addressees) from patch revisions. > > [ +cc linux-serial] Will fix this. > Please update Documentation/kernel-parameters.txt with pci-specific > earlycon parameter formats. Will do. > Please move this hunk to patch 2/2. It's already in 2/2. Or I'm not quite understanding? > FYI, there is a proposal to evaluate "earlyprintk=" earlier than > parse_early_params(), which this would break. > > https://lkml.org/lkml/2015/5/18/127 No, it wouldn't. The proposal only moves earlyprintk=serial(legacy 0x3f8). If you look into arch/x86/kernel/early_printk.c, you'll find many other options other than serial, e.g. vga, dbgp, xen, efi, pciserial, etc. uart8250(previously pciserial) is one of these "others". > > +static int parse_bdf(char *options, char **endp, char delimiter, u8 *val) > > If this function is only used from parse_pci_options(), please enclose it > in #ifdef CONFIG_PCI_EARLY scope with parse_pci_options(). Yes, will fix it. > > > +{ > > + char str[4]; /* max 3 chars, plus a NULL terminator */ > > + char *p = options; > > + int i = 0; > > + > > + while (*p) { > > + if (i >= 4) > > + return -EINVAL; > > + > > + if (*p == delimiter) { > > + str[i++] = 0; > > + if (endp) > > + *endp = p + 1; > > + return kstrtou8(str, 10, val); /* decimal, no hex */ > > + } > > + > > + str[i++] = *p++; > > + } > > Is all this to avoid using simple_strtoul()? > If yes, I'd rather you use simple_strtoul() like the rest of the console > code and ignore the (misguided) advice that simple_strtoul() is obsolete. Then scripts/checkpatch.pl should be updated to avoid this kind of "misguiding". Also the kstrto* API descriptions should be updated... > The code above is exactly what is wrong with the kstrto* api. Can you elaborate a little bit? Thanks. > > + if (!early_pci_allowed()) { > > + pr_err("earlycon pci not available(early pci not allowed)\n"); > > Error message is redundant. "early pci not allowed" is the reason of "earlycon pci not available". > > + /* > > + * On these platforms class code in pci config is broken, > ^^^^^^^^^^^^^^^ > which platforms? On platforms where this code will run on. Do you prefer something like: On platforms with early pci serial class code in pci config is broken, > > + pr_info("Use 8250 uart at PCI 0000:%02u:%02u.%01u as early console\n", > > + bus, dev, func); > > I think one earlycon banner is sufficient; you could make this pr_debug() > instead. Existing convention for earlycon messages is > > "earlycon: ...." Will use pr_debug(). > > * @options: ptr for <options> field; NULL if not present (out) > > * > > * Decodes earlycon kernel command line parameters of the form > > - * earlycon=<name>,io|mmio|mmio32,<addr>,<options> > > + * earlycon=<name>,io|mmio|mmio32|pci|pci32,<addr>,<options> > > Document the pci/pci32 format separately because > earlycon=uart8250,pci32,<addr>,<options> is not a valid form. Why it's not a valid form? It follows the existed syntax like this: earlycon=uart8250,<io type>,<addr>,<options> > > @@ -1829,12 +1939,23 @@ uart_get_console(struct uart_port *ports, int nr, > > struct console *co) > > int uart_parse_earlycon(char *p, unsigned char *iotype, unsigned long > > *addr, > > char **options) > > { > > + int pci = 0, ret; > > + unsigned long phys; > > + > > if (strncmp(p, "mmio,", 5) == 0) { > > *iotype = UPIO_MEM; > > p += 5; > > } else if (strncmp(p, "mmio32,", 7) == 0) { > > *iotype = UPIO_MEM32; > > p += 7; > > + } else if (strncmp(p, "pci,", 4) == 0) { > > + pci = 1; > > + p += 4; > > + ret = parse_pci_options(p, &phys); > > + } else if (strncmp(p, "pci32,", 6) == 0) { > > + pci = 2; > > + p += 6; > > + ret = parse_pci_options(p, &phys); > > } else if (strncmp(p, "io,", 3) == 0) { > > *iotype = UPIO_PORT; > > p += 3; > > @@ -1844,7 +1965,27 @@ int uart_parse_earlycon(char *p, unsigned char > > *iotype, unsigned long *addr, > > return -EINVAL; > > } > > > > - *addr = simple_strtoul(p, NULL, 0); > > + if (pci) { > > + if (ret < 0) /* error */ > > + return ret; > > + > > + /* > > + * Once PCI mem/io is read from PCI BAR, we can reuse > > + * mmio/mmio32/io type to minimize code change. > > + */ > > + if (ret > 0) /* PCI io */ > > + *iotype = UPIO_PORT; > > + else { /* ret = 0: PCI mem */ > > + if (pci == 2) > > + *iotype = UPIO_MEM32; > > + else > > + *iotype = UPIO_MEM; > > + } > > + > > + *addr = phys; > > + } else > > + *addr = simple_strtoul(p, NULL, 0); > > + > > I'd like to see this refactored without the logic steering locals. > Like this: > > if (strncmp(p, "mmio,", 5) == 0) { > *iotype = UPIO_MEM; > p += 5; > + *addr = simple_strtoul(p, NULL, 0); > } else if (strncmp(p, "mmio32,", 7) == 0) { > *iotype = UPIO_MEM32; > p += 7; > + *addr = simple_strtoul(p, NULL, 0); > + } else if (strncmp(p, "pci,", 4) == 0) { > + pci = 1; > + p += 4; > + ret = parse_pci_options(p, addr); > + if (ret < 0) > + return ret; > + *iotype = (ret > 0) ? UPIO_PORT : UPIO_MEM; > + } else if (strncmp(p, "pci32,", 6) == 0) { > + pci = 2; > + p += 6; > + ret = parse_pci_options(p, addr); > + if (ret < 0) > + return ret; > + *iotype = (ret > 0) ? UPIO_PORT : UPIO_MEM32; > } else if (strncmp(p, "io,", 3) == 0) { > *iotype = UPIO_PORT; > p += 3; > + *addr = simple_strtoul(p, NULL, 0); > > > Regards, > Peter Hurley > > > - *addr = simple_strtoul(p, NULL, 0); > > p = strchr(p, ','); > > if (p) > > p++; > > Ah, this is kind of coding style. But I agree with your suggestion. Will fix it. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
