3.2.69-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Stefan Lippers-Hollmann <s.l-h@xxxxxx> commit 80313b3078fcd2ca51970880d90757f05879a193 upstream. The ASRock Q1900DC-ITX mainboard (Baytrail-D) hangs randomly in both BIOS and UEFI mode while rebooting unless reboot=pci is used. Add a quirk to reboot via the pci method. The problem is very intermittent and hard to debug, it might succeed rebooting just fine 40 times in a row - but fails half a dozen times the next day. It seems to be slightly less common in BIOS CSM mode than native UEFI (with the CSM disabled), but it does happen in either mode. Since I've started testing this patch in late january, rebooting has been 100% reliable. Most of the time it already hangs during POST, but occasionally it might even make it through the bootloader and the kernel might even start booting, but then hangs before the mode switch. The same symptoms occur with grub-efi, gummiboot and grub-pc, just as well as (at least) kernel 3.16-3.19 and 4.0-rc6 (I haven't tried older kernels than 3.16). Upgrading to the most current mainboard firmware of the ASRock Q1900DC-ITX, version 1.20, does not improve the situation. ( Searching the web seems to suggest that other Bay Trail-D mainboards might be affected as well. ) -- Signed-off-by: Stefan Lippers-Hollmann <s.l-h@xxxxxx> Cc: Matt Fleming <matt.fleming@xxxxxxxxx> Link: http://lkml.kernel.org/r/20150330224427.0fb58e42@mir Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- --- a/arch/x86/kernel/reboot.c +++ b/arch/x86/kernel/reboot.c @@ -412,6 +412,15 @@ static struct dmi_system_id __initdata p DMI_MATCH(DMI_PRODUCT_NAME, "iMac9,1"), }, }, + /* ASRock */ + { /* Handle problems with rebooting on ASRock Q1900DC-ITX */ + .callback = set_pci_reboot, + .ident = "ASRock Q1900DC-ITX", + .matches = { + DMI_MATCH(DMI_BOARD_VENDOR, "ASRock"), + DMI_MATCH(DMI_BOARD_NAME, "Q1900DC-ITX"), + }, + }, /* Certec */ { /* Handle problems with rebooting on Certec BPC600 */ .callback = set_pci_reboot, -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html