This is a note to let you know that I've just added the patch titled drm/i915: Remove memory frequency calculation to the 5.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-i915-remove-memory-frequency-calculation.patch and it can be found in the queue-5.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 59be177a909ac320e5f4b2a461ac09e20f35b2d8 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Jos=C3=A9=20Roberto=20de=20Souza?= <jose.souza@xxxxxxxxx> Date: Tue, 12 Oct 2021 18:00:46 -0700 Subject: drm/i915: Remove memory frequency calculation MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: José Roberto de Souza <jose.souza@xxxxxxxxx> commit 59be177a909ac320e5f4b2a461ac09e20f35b2d8 upstream. This memory frequency calculated is only used to check if it is zero, what is not useful as it will never actually be zero. Also the calculation is wrong, we should be checking other bit to select the appropriate frequency multiplier while this code is stuck with a fixed multiplier. So here dropping it as whole. v2: - Also remove memory frequency calculation for gen9 LP platforms Cc: Yakui Zhao <yakui.zhao@xxxxxxxxx> Cc: Matt Roper <matthew.d.roper@xxxxxxxxx> Fixes: 5d0c938ec9cc ("drm/i915/gen11+: Only load DRAM information from pcode") Signed-off-by: José Roberto de Souza <jose.souza@xxxxxxxxx> Reviewed-by: Matt Roper <matthew.d.roper@xxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20211013010046.91858-1-jose.souza@xxxxxxxxx (cherry picked from commit 83f52364b15265aec47d07e02b0fbf4093ab8554) Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/i915/i915_reg.h | 8 -------- drivers/gpu/drm/i915/intel_dram.c | 30 ++---------------------------- 2 files changed, 2 insertions(+), 36 deletions(-) --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -11021,12 +11021,6 @@ enum skl_power_gate { #define DC_STATE_DEBUG_MASK_CORES (1 << 0) #define DC_STATE_DEBUG_MASK_MEMORY_UP (1 << 1) -#define BXT_P_CR_MC_BIOS_REQ_0_0_0 _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x7114) -#define BXT_REQ_DATA_MASK 0x3F -#define BXT_DRAM_CHANNEL_ACTIVE_SHIFT 12 -#define BXT_DRAM_CHANNEL_ACTIVE_MASK (0xF << 12) -#define BXT_MEMORY_FREQ_MULTIPLIER_HZ 133333333 - #define BXT_D_CR_DRP0_DUNIT8 0x1000 #define BXT_D_CR_DRP0_DUNIT9 0x1200 #define BXT_D_CR_DRP0_DUNIT_START 8 @@ -11057,9 +11051,7 @@ enum skl_power_gate { #define BXT_DRAM_TYPE_LPDDR4 (0x2 << 22) #define BXT_DRAM_TYPE_DDR4 (0x4 << 22) -#define SKL_MEMORY_FREQ_MULTIPLIER_HZ 266666666 #define SKL_MC_BIOS_DATA_0_0_0_MCHBAR_PCU _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x5E04) -#define SKL_REQ_DATA_MASK (0xF << 0) #define SKL_MAD_INTER_CHANNEL_0_0_0_MCHBAR_MCMAIN _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x5000) #define SKL_DRAM_DDR_TYPE_MASK (0x3 << 0) --- a/drivers/gpu/drm/i915/intel_dram.c +++ b/drivers/gpu/drm/i915/intel_dram.c @@ -244,7 +244,6 @@ static int skl_get_dram_info(struct drm_i915_private *i915) { struct dram_info *dram_info = &i915->dram_info; - u32 mem_freq_khz, val; int ret; dram_info->type = skl_get_dram_type(i915); @@ -255,17 +254,6 @@ skl_get_dram_info(struct drm_i915_privat if (ret) return ret; - val = intel_uncore_read(&i915->uncore, - SKL_MC_BIOS_DATA_0_0_0_MCHBAR_PCU); - mem_freq_khz = DIV_ROUND_UP((val & SKL_REQ_DATA_MASK) * - SKL_MEMORY_FREQ_MULTIPLIER_HZ, 1000); - - if (dram_info->num_channels * mem_freq_khz == 0) { - drm_info(&i915->drm, - "Couldn't get system memory bandwidth\n"); - return -EINVAL; - } - return 0; } @@ -350,24 +338,10 @@ static void bxt_get_dimm_info(struct dra static int bxt_get_dram_info(struct drm_i915_private *i915) { struct dram_info *dram_info = &i915->dram_info; - u32 dram_channels; - u32 mem_freq_khz, val; - u8 num_active_channels, valid_ranks = 0; + u32 val; + u8 valid_ranks = 0; int i; - val = intel_uncore_read(&i915->uncore, BXT_P_CR_MC_BIOS_REQ_0_0_0); - mem_freq_khz = DIV_ROUND_UP((val & BXT_REQ_DATA_MASK) * - BXT_MEMORY_FREQ_MULTIPLIER_HZ, 1000); - - dram_channels = val & BXT_DRAM_CHANNEL_ACTIVE_MASK; - num_active_channels = hweight32(dram_channels); - - if (mem_freq_khz * num_active_channels == 0) { - drm_info(&i915->drm, - "Couldn't get system memory bandwidth\n"); - return -EINVAL; - } - /* * Now read each DUNIT8/9/10/11 to check the rank of each dimms. */ Patches currently in stable-queue which might be from jose.souza@xxxxxxxxx are queue-5.14/drm-i915-remove-memory-frequency-calculation.patch