[PATCH v3 4/4] drm/i915/dg2: Implement Wa_14022698537

Raag Jadav
2024-10-30T14:35:04Z

G8 power state entry is disabled due to a limitation on DG2, so we
enable it from driver with Wa_14022698537. For now we enable it for
all DG2 devices with the exception of a few, for which, we enable
only when paired with whitelisted CPU models. This works with Native
ASMP and reduces idle power consumption.

$ echo powersave > /sys/module/pcie_aspm/parameters/policy
$ lspci -s 0000:03:00.0 -vvv
LnkCtl: ASPM L1 Enabled; RCB 64 bytes, Disabled- CommClk-

v2: Fix Wa_ID and include it in subject (Badal)
Rephrase commit message (Jani)
v3: Move workaround to i915_pcode_init() (Badal, Anshuman)
Re-order macro (Riana)

Signed-off-by: Raag Jadav <raag.jadav@intel.com>
---
drivers/gpu/drm/i915/i915_driver.c | 15 +++++++++++++++
drivers/gpu/drm/i915/i915_reg.h | 1 +
2 files changed, 16 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_driver.c b/drivers/gpu/drm/i915/i915_driver.c
index 365329ff8a07..59c6124c9bc2 100644
--- a/drivers/gpu/drm/i915/i915_driver.c
+++ b/drivers/gpu/drm/i915/i915_driver.c
@@ -93,12 +93,14 @@
#include "i915_memcpy.h"
#include "i915_perf.h"
#include "i915_query.h"
+#include "i915_reg.h"
#include "i915_suspend.h"
#include "i915_switcheroo.h"
#include "i915_sysfs.h"
#include "i915_utils.h"
#include "i915_vgpu.h"
#include "intel_clock_gating.h"
+#include "intel_cpu_info.h"
#include "intel_gvt.h"
#include "intel_memory_region.h"
#include "intel_pci_config.h"
@@ -415,6 +417,18 @@ static int i915_set_dma_info(struct drm_i915_private *i915)
return ret;
}

+/* Wa_14022698537:dg2 */
+static void i915_enable_g8(struct drm_i915_private *i915)
+{
+ if (IS_DG2(i915)) {
+ if (IS_DG2_D(i915) && !intel_match_g8_cpu())
+ return;
+
+ snb_pcode_write_p(&i915->uncore, PCODE_POWER_SETUP,
+ POWER_SETUP_SUBCOMMAND_G8_ENABLE, 0, 0);
+ }
+}
+
static int i915_pcode_init(struct drm_i915_private *i915)
{
struct intel_gt *gt;
@@ -428,6 +442,7 @@ static int i915_pcode_init(struct drm_i915_private *i915)
}
}

+ i915_enable_g8(i915);
return 0;
}

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 89e4381f8baa..d400c77423a5 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -3617,6 +3617,7 @@
#define POWER_SETUP_I1_WATTS REG_BIT(31)
#define POWER_SETUP_I1_SHIFT 6 /* 10.6 fixed point format */
#define POWER_SETUP_I1_DATA_MASK REG_GENMASK(15, 0)
+#define POWER_SETUP_SUBCOMMAND_G8_ENABLE 0x6
#define GEN12_PCODE_READ_SAGV_BLOCK_TIME_US 0x23
#define XEHP_PCODE_FREQUENCY_CONFIG 0x6e /* pvc */
/* XEHP_PCODE_FREQUENCY_CONFIG sub-commands (param1) */
--
2.34.1