Hi Wolfgang,
On Fri, 4 Sep 2020 at 08:16, Wolfgang Wallner wolfgang.wallner@br-automation.com wrote:
Hi Simon, Bin,
-----"Simon Glass" sjg@chromium.org schrieb: -----
Betreff: [PATCH v2 08/57] x86: acpi: Support external GNVS tables
At present U-Boot puts a magic number in the ASL for the GNVS table and searches for it later.
Add a Kconfig option to use a different approach, where the ASL files declare the table as an external symbol. U-Boot can then put it wherever it likes, without any magic numbers or searching.
Signed-off-by: Simon Glass sjg@chromium.org
[snip]
diff --git a/arch/x86/lib/acpi_table.c b/arch/x86/lib/acpi_table.c
[snip]
acpi_inc_align(ctx, dsdt->length - sizeof(struct acpi_table_header));
dsdt->length = ctx->current - (void *)dsdt;While testing the latest series of ACPI patches I saw strange behavior when booting Linux. Sometimes it would boot, sometimes it would hang, sometimes it would boot but show ACPI-related errors in dmesg.
Debugging showed that the reason is that the calculated length of the DSDT in the above code includes any additional bytes that were added for alignment, and those are not initialized. I gues the Linux ACPI implementation tries to decode those, and then something crashes.
Changing the above two lines to the following
acpi_inc(ctx, dsdt->length - sizeof(struct acpi_table_header)); dsdt->length = ctx->current - (void *)dsdt; acpi_align(ctx);
fixes the issue for me.
But the issue already exists in the previous code. Would it be better to send a patch which applies to the currrent master, or on top of the ACPI series?
I think to the current master would be better. I have seen that problem so thank you for figuring it out!
Regards, SImon