On Tue, Jul 29, 2014 at 11:21 PM, Lv Zheng <lv.zheng@xxxxxxxxx> wrote: > From: Tomasz Nowicki <tomasz.nowicki@xxxxxxxxxx> > > New fields and new subtables. Tomasz Nowicki. > tomasz.nowicki@xxxxxxxxxx > > Signed-off-by: Tomasz Nowicki <tomasz.nowicki@xxxxxxxxxx> > Signed-off-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx> > Signed-off-by: Bob Moore <robert.moore@xxxxxxxxx> > Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx> Hi, I know this patch is old, but something confuses me about it: > +/* Common GTDT subtable header */ > + > +struct acpi_gtdt_header { > + u8 type; > + u16 length; > +}; I'm trying to write a function that parses the watchdog structure (acpi_gtdt_watchdog). The first entry in that structure is acpi_gtdt_header. Looking at the ACPI specification, I see that this is correct: the type is one byte, and the length is two bytes. However, this means that I cannot use acpi_parse_entries() to parse the watchdog subtable: int __init acpi_parse_entries(char *id, unsigned long table_size, acpi_tbl_entry_handler handler, struct acpi_table_header *table_header, int entry_id, unsigned int max_entries) acpi_tbl_entry_handler takes an acpi_subtable_header as its first parameter. However, that structure looks like this: struct acpi_subtable_header { u8 type; u8 length; }; This is not compatible, so I'm confused now. How do I properly parse the watchdog subtable, if I cannot use acpi_parse_entries? For context, here is my patch: http://www.spinics.net/lists/linux-watchdog/msg06240.html Scroll down to function arm_sbsa_wdt_parse_gtdt(). The typecast in first line is invalid: + struct acpi_gtdt_watchdog *wdg = (struct acpi_gtdt_watchdog *)header; because of the mismatch. I don't know how to fix this. -- 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