[coreboot-gerrit] New patch to review for coreboot: skylake: Increase IGD stolen size to 64MB

[Patrick Georgi (pgeorgi@google.com)]

Patrick Georgi (pgeorgi at google.com) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/13833

-gerrit

commit 738d489a5a24dd6a37f5477ce0b05c59d8a8fcd9
Author: Duncan Laurie <dlaurie at chromium.org>
Date:   Sat Feb 20 09:10:53 2016 -0800

    skylake: Increase IGD stolen size to 64MB
    
    The FBC hardware for skylake does not have access to the bios_reserved
    range so it always assumes 8MB is used and so the kernel will
    therefore need to avoid using the last 8MB of the stolen window.
    With the default stolen size of 32MB(-8MB) there is not enough space
    for FBC to work with a high resolution panel.
    
    Kernel reference:
    http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=a9da512b3ed73045253afd778e40d4298f42905b
    
    BUG=chrome-os-partner:50396
    BRANCH=glados
    TEST=build and boot on chell DVT
    
    Change-Id: I3049d7d9e7c551aad5b8fd1630d5fbd88ccb2692
    Signed-off-by: Patrick Georgi <pgeorgi at google.com>
    Original-Commit-Id: fff1f4b35e23e77cdc72c5bcc290f199494cdbbb
    Original-Change-Id: If468cca5759a320f3cd2d7eb09f4bcc0117b24cb
    Original-Signed-off-by: Duncan Laurie <dlaurie at chromium.org>
    Original-Reviewed-on: https://chromium-review.googlesource.com/328813
    Original-Reviewed-by: Aaron Durbin <adurbin at chromium.org>
---
 src/soc/intel/skylake/romstage/romstage.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/soc/intel/skylake/romstage/romstage.c b/src/soc/intel/skylake/romstage/romstage.c
index 9b95f72..9c61095 100644
--- a/src/soc/intel/skylake/romstage/romstage.c
+++ b/src/soc/intel/skylake/romstage/romstage.c
@@ -85,6 +85,15 @@ void soc_memory_init_params(struct romstage_params *params,
 	dev = dev_find_slot(0, PCI_DEVFN(PCH_DEV_SLOT_LPC, 0));
 	config = dev->chip_info;
 
+	/*
+	 * Set IGD stolen size to 64MB.  The FBC hardware for skylake does not
+	 * have access to the bios_reserved range so it always assumes 8MB is
+	 * used and so the kernel will avoid the last 8MB of the stolen window.
+	 * With the default stolen size of 32MB(-8MB) there is not enough space
+	 * for FBC to work with a high resolution panel.
+	 */
+	upd->IgdDvmt50PreAlloc = 2;
+
 	upd->MmioSize = 0x800; /* 2GB in MB */
 	upd->TsegSize = CONFIG_SMM_TSEG_SIZE;
 	upd->IedSize = CONFIG_IED_REGION_SIZE;