Patrick Rudolph (siro@das-labor.org) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/11059
-gerrit
commit a1ea28ec6b9f6dd577b1df325c1cf5eb4a80e30c Author: Patrick Rudolph siro@das-labor.org Date: Tue Jul 28 08:01:02 2015 +0200
intel sandybridge: enable PEG clock-gating on demand
Activate PEG clock-gating only if all PEG devices are disabled. Fixes system hang when trying to access PEG registers.
Test system: * Intel Pentium CPU G2130 * Gigabyte GA-B75M-D3H
Change-Id: I7d62fbb83c16741965639cea1a0e4978d4e3d6da Signed-off-by: Patrick Rudolph siro@das-labor.org --- src/northbridge/intel/sandybridge/northbridge.c | 48 ++++++++++++++++++++++ src/northbridge/intel/sandybridge/raminit.c | 8 ---- src/northbridge/intel/sandybridge/raminit_native.c | 7 ---- 3 files changed, 48 insertions(+), 15 deletions(-)
diff --git a/src/northbridge/intel/sandybridge/northbridge.c b/src/northbridge/intel/sandybridge/northbridge.c index 0e0ba00..76f03f3 100644 --- a/src/northbridge/intel/sandybridge/northbridge.c +++ b/src/northbridge/intel/sandybridge/northbridge.c @@ -361,6 +361,51 @@ static void northbridge_dmi_init(struct device *dev) DMIBAR32(0x88) = reg32; }
+/* Disable unused PEG devices based on devicetree */ +static void disable_peg(void) +{ + struct device *dev; + u32 reg; + + dev = dev_find_slot(0, PCI_DEVFN(0, 0)); + reg = pci_read_config32(dev, DEVEN); + + dev = dev_find_slot(0, PCI_DEVFN(1, 2)); + if (!dev || !dev->enabled) { + printk(BIOS_DEBUG, "Disabling PEG12.\n"); + reg &= ~DEVEN_PEG12; + } + dev = dev_find_slot(0, PCI_DEVFN(1, 1)); + if (!dev || !dev->enabled) { + printk(BIOS_DEBUG, "Disabling PEG11.\n"); + reg &= ~DEVEN_PEG11; + } + dev = dev_find_slot(0, PCI_DEVFN(1, 0)); + if (!dev || !dev->enabled) { + printk(BIOS_DEBUG, "Disabling PEG10.\n"); + reg &= ~DEVEN_PEG10; + } + dev = dev_find_slot(0, PCI_DEVFN(2, 0)); + if (!dev || !dev->enabled) { + printk(BIOS_DEBUG, "Disabling IGD.\n"); + reg &= ~DEVEN_IGD; + } + dev = dev_find_slot(0, PCI_DEVFN(6, 0)); + if (!dev || !dev->enabled) { + printk(BIOS_DEBUG, "Disabling PEG60.\n"); + reg &= ~DEVEN_PEG60; + } + + dev = dev_find_slot(0, PCI_DEVFN(0, 0)); + pci_write_config32(dev, DEVEN, reg); + if (!(reg & (DEVEN_PEG60 | DEVEN_PEG10 | DEVEN_PEG11 | DEVEN_PEG12))) { + /* Set the PEG clock gating bit. + * Disables the IO clock on all PEG devices. */ + MCHBAR32(0x7010) = MCHBAR32(0x7010) | 0x01; + printk(BIOS_DEBUG, "Disabling PEG IO clock.\n"); + } +} + static void northbridge_init(struct device *dev) { u8 bios_reset_cpl; @@ -411,6 +456,9 @@ static void northbridge_init(struct device *dev)
/* Set here before graphics PM init */ MCHBAR32(0x5500) = 0x00100001; + + /* Turn off unused devices */ + disable_peg(); }
static void northbridge_enable(device_t dev) diff --git a/src/northbridge/intel/sandybridge/raminit.c b/src/northbridge/intel/sandybridge/raminit.c index 053a487..1f6b75c 100644 --- a/src/northbridge/intel/sandybridge/raminit.c +++ b/src/northbridge/intel/sandybridge/raminit.c @@ -199,13 +199,6 @@ static void report_memory_config(void) } }
-static void post_system_agent_init(struct pei_data *pei_data) -{ - /* If PCIe init is skipped, set the PEG clock gating */ - if (!pei_data->pcie_init) - MCHBAR32(0x7010) = MCHBAR32(0x7010) | 0x01; -} - /** * Find PEI executable in coreboot filesystem and execute it. * @@ -288,6 +281,5 @@ void sdram_initialize(struct pei_data *pei_data) else intel_early_me_status();
- post_system_agent_init(pei_data); report_memory_config(); } diff --git a/src/northbridge/intel/sandybridge/raminit_native.c b/src/northbridge/intel/sandybridge/raminit_native.c index 790f47c..9df102a 100644 --- a/src/northbridge/intel/sandybridge/raminit_native.c +++ b/src/northbridge/intel/sandybridge/raminit_native.c @@ -234,12 +234,6 @@ static void report_memory_config(void) } }
-static void post_system_agent_init(void) -{ - /* If PCIe init is skipped, set the PEG clock gating */ - MCHBAR32(0x7010) = MCHBAR32(0x7010) | 0x01; -} - void read_spd(spd_raw_data * spd, u8 addr) { int j; @@ -3888,7 +3882,6 @@ void init_dram_ddr3(spd_raw_data * spds, int mobile, int min_tck, intel_early_me_init_done(ME_INIT_STATUS_SUCCESS); intel_early_me_status();
- post_system_agent_init(); report_memory_config();
cbmem_was_inited = !cbmem_recovery(s3resume);