On 09/14/14 at 07:42pm, Greg KH wrote: > On Mon, Sep 15, 2014 at 10:38:05AM +0800, Dave Young wrote: > > On 09/14/14 at 03:14pm, Matt Fleming wrote: > > > On Tue, 26 Aug, at 05:06:41PM, Dave Young wrote: > > > > 3.16 kernel boot fail with earlyprintk=efi, it keeps scrolling at the > > > > bottom line of screen. > > > > > > > > Bisected, the first bad commit is below: > > > > commit 86dfc6f339886559d80ee0d4bd20fe5ee90450f0 > > > > Author: Lv Zheng <lv.zheng@xxxxxxxxx> > > > > Date: Fri Apr 4 12:38:57 2014 +0800 > > > > > > > > ACPICA: Tables: Fix table checksums verification before installation. > > > > > > [...] > > > > > > > Quote reply from Lv.zheng about the early ioremap slot usage in this case: > > > > > > > > """ > > > > In early_efi_scroll_up(), 2 mapping entries will be used for the src/dst screen buffer. > > > > In drivers/acpi/acpica/tbutils.c, we've improved the early table loading code in acpi_tb_parse_root_table(). > > > > We now need 2 mapping entries: > > > > 1. One mapping entry is used for RSDT table mapping. Each RSDT entry contains an address for another ACPI table. > > > > 2. For each entry in RSDP, we need another mapping entry to map the table to perform necessary check/override before installing it. > > > > > > > > When acpi_tb_parse_root_table() prints something through EFI earlyprintk console, we'll have 4 mapping entries used. > > > > The current 4 slots setting of early_ioremap() seems to be too small for such a use case. > > > > """ > > > > > > > > Thus increase the slot to 8 in this patch to fix this issue. > > > > boot-time mappings become 512 page with this patch. > > > > > > This analysis and solution makes sense to me, but I was really hoping > > > for one of the x86 maintainers to ACK the below patch. I'm happy to take > > > it through the EFI tree if it's not picked up into tip meanwhile. > > > > > > Also, Dave, it sounds like this should be tagged for stable if the bug > > > has been around since v3.16? > > > > Matt, yes, it should be a stable issue, ccing Greg and stable list. > > <formletter> > > This is not the correct way to submit patches for inclusion in the > stable kernel tree. Please read Documentation/stable_kernel_rules.txt > for how to do this properly. > > </formletter> Frankly I did not know the exact work flow about stable patches. Thanks for pointing me the documentation. I was just assuming I should cc your guys about the issues which could be stable candidate even though it has not been accepted now, so it can get noticed by stable people. Thanks Dave -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
