Re: [PATCH v5 2/4] x86: add support for earlyprintk via USB3 debug port

From: Ingo Molnar
Date: Thu Jan 19 2017 - 04:42:05 EST



* Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> wrote:

> index 8a12199..c4031b9 100644
> --- a/arch/x86/kernel/early_printk.c
> +++ b/arch/x86/kernel/early_printk.c
> @@ -17,6 +17,7 @@
> #include <asm/intel-mid.h>
> #include <asm/pgtable.h>
> #include <linux/usb/ehci_def.h>
> +#include <linux/usb/xhci-dbgp.h>
> #include <linux/efi.h>
> #include <asm/efi.h>
> #include <asm/pci_x86.h>
> @@ -381,6 +382,10 @@ static int __init setup_early_printk(char *buf)
> if (!strncmp(buf, "efi", 3))
> early_console_register(&early_efi_console, keep);
> #endif
> +#ifdef CONFIG_EARLY_PRINTK_XDBC
> + if (!strncmp(buf, "xdbc", 4))
> + early_xdbc_parse_parameter(buf + 4);
> +#endif
>
> buf++;
> }
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index 9c337b0..09d4a56 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -70,6 +70,8 @@
> #include <linux/tboot.h>
> #include <linux/jiffies.h>
>
> +#include <linux/usb/xhci-dbgp.h>
> +
> #include <video/edid.h>
>
> #include <asm/mtrr.h>
> @@ -1096,6 +1098,11 @@ void __init setup_arch(char **cmdline_p)
> memblock_set_current_limit(ISA_END_ADDRESS);
> memblock_x86_fill();
>
> +#ifdef CONFIG_EARLY_PRINTK_XDBC
> + if (!early_xdbc_setup_hardware())
> + early_xdbc_register_console();
> +#endif
> +
> reserve_bios_regions();
>
> if (efi_enabled(EFI_MEMMAP)) {
> --
> 2.1.4

Please create proper wrappers in xhci-dbgp.h to not litter generic code with these
#ifdefs.

Thanks,

Ingo