From 2c2868a76667270b5f1373094d1bff8a000683ef Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Wed, 31 Jul 2024 19:05:15 +0200 Subject: [PATCH] ALSA: hda: Conditionally use snooping for AMD HDMI [ Upstream commit 478689b5990deb626a0b3f1ebf165979914d6be4 ] The recent regression report revealed that the use of WC pages for AMD HDMI device together with AMD IOMMU leads to unexpected truncation or noises. The issue seems triggered by the change in the kernel core memory allocation that enables IOMMU driver to use always S/G buffers. Meanwhile, the use of WC pages has been a workaround for the similar issue with standard pages in the past. So, now we need to apply the workaround conditionally, namely, only when IOMMU isn't in place. This patch modifies the workaround code to check the DMA ops at first and apply the snoop-off only when needed. Fixes: f5ff79fddf0e ("dma-mapping: remove CONFIG_DMA_REMAP") Link: https://bugzilla.kernel.org/show_bug.cgi?id=219087 Link: https://patch.msgid.link/20240731170521.31714-1-tiwai@suse.de Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- sound/pci/hda/hda_controller.h | 2 +- sound/pci/hda/hda_intel.c | 10 +++++++++- 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/sound/pci/hda/hda_controller.h b/sound/pci/hda/hda_controller.h index 8556031bcd68..f31cb31d4636 100644 --- a/sound/pci/hda/hda_controller.h +++ b/sound/pci/hda/hda_controller.h @@ -28,7 +28,7 @@ #else #define AZX_DCAPS_I915_COMPONENT 0 /* NOP */ #endif -/* 14 unused */ +#define AZX_DCAPS_AMD_ALLOC_FIX (1 << 14) /* AMD allocation workaround */ #define AZX_DCAPS_CTX_WORKAROUND (1 << 15) /* X-Fi workaround */ #define AZX_DCAPS_POSFIX_LPIB (1 << 16) /* Use LPIB as default */ #define AZX_DCAPS_AMD_WORKAROUND (1 << 17) /* AMD-specific workaround */ diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index a6a9d353fe63..d5c9f113e477 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -40,6 +40,7 @@ #ifdef CONFIG_X86 /* for snoop control */ +#include #include #include #endif @@ -301,7 +302,7 @@ enum { /* quirks for ATI HDMI with snoop off */ #define AZX_DCAPS_PRESET_ATI_HDMI_NS \ - (AZX_DCAPS_PRESET_ATI_HDMI | AZX_DCAPS_SNOOP_OFF) + (AZX_DCAPS_PRESET_ATI_HDMI | AZX_DCAPS_AMD_ALLOC_FIX) /* quirks for AMD SB */ #define AZX_DCAPS_PRESET_AMD_SB \ @@ -1715,6 +1716,13 @@ static void azx_check_snoop_available(struct azx *chip) if (chip->driver_caps & AZX_DCAPS_SNOOP_OFF) snoop = false; +#ifdef CONFIG_X86 + /* check the presence of DMA ops (i.e. IOMMU), disable snoop conditionally */ + if ((chip->driver_caps & AZX_DCAPS_AMD_ALLOC_FIX) && + !get_dma_ops(chip->card->dev)) + snoop = false; +#endif + chip->snoop = snoop; if (!snoop) { dev_info(chip->card->dev, "Force to non-snoop mode\n");