Messages in this thread | | | Date | Wed, 04 Feb 2015 17:38:25 +0800 | From | Hanjun Guo <> | Subject | Re: [PATCH v8 09/21] ARM64 / ACPI: Disable ACPI if FADT revision is less than 5.1 |
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On 2015年02月04日 01:20, Catalin Marinas wrote: > On Mon, Feb 02, 2015 at 12:45:37PM +0000, Hanjun Guo wrote: >> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c >> index afe10b4..b9f64ec 100644 >> --- a/arch/arm64/kernel/acpi.c >> +++ b/arch/arm64/kernel/acpi.c >> @@ -13,6 +13,8 @@ >> * published by the Free Software Foundation. >> */ >> >> +#define pr_fmt(fmt) "ACPI: " fmt >> + >> #include <linux/acpi.h> >> #include <linux/bootmem.h> >> #include <linux/cpumask.h> >> @@ -49,10 +51,32 @@ void __init __acpi_unmap_table(char *map, unsigned long size) >> early_memunmap(map, size); >> } >> >> +static int __init acpi_parse_fadt(struct acpi_table_header *table) >> +{ >> + struct acpi_table_fadt *fadt = (struct acpi_table_fadt *)table; >> + >> + /* >> + * Revision in table header is the FADT Major revision, and there >> + * is a minor revision of FADT which was introduced by ACPI 5.1, >> + * we only deal with ACPI 5.1 or newer revision to get GIC and SMP >> + * boot protocol configuration data, or we will disable ACPI. >> + */ >> + if (table->revision > 5 || >> + (table->revision == 5 && fadt->minor_revision >= 1)) >> + return 0; >> + >> + pr_warn("Unsupported FADT revision %d.%d, should be 5.1+, will disable ACPI\n", >> + table->revision, fadt->minor_revision); >> + disable_acpi(); >> + >> + return -EINVAL; >> +} >> + >> /* >> * acpi_boot_table_init() called from setup_arch(), always. >> * 1. find RSDP and get its address, and then find XSDT >> * 2. extract all tables and checksums them all >> + * 3. check ACPI FADT revision >> * >> * We can parse ACPI boot-time tables such as MADT after >> * this function is called. >> @@ -64,8 +88,16 @@ void __init acpi_boot_table_init(void) >> return; >> >> /* Initialize the ACPI boot-time table parser. */ >> - if (acpi_table_init()) >> + if (acpi_table_init()) { >> + disable_acpi(); >> + return; >> + } >> + >> + if (acpi_table_parse(ACPI_SIG_FADT, acpi_parse_fadt)) { >> + /* disable ACPI if no FADT is found */ >> disable_acpi(); >> + pr_err("Can't find FADT\n"); >> + } >> } > > It looks fine to call disable_acpi() here but a bit weird to call it > again in acpi_parse_fadt(). I guess that's because acpi_table_parse() > ignores the return value of the handler() call. I think it's better to > fix the core code (can be an additional patch on top of this series).
I checked all the code calling acpi_table_parse() and I found that it will be no functional change if we return the value of handler(), but I need Rafael's confirm on it.
Thanks Hanjun
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