ASoC: mediatek: use reserved memory or enable buffer pre-allocation

In commit 32c9c06adb5b ("ASoC: mediatek: disable buffer pre-allocation")
buffer pre-allocation was disabled to accommodate newer platforms that
have a limited reserved memory region for the audio frontend.

Turns out disabling pre-allocation across the board impacts platforms
that don't have this reserved memory region. Buffer allocation failures
have been observed on MT8173 and MT8183 based Chromebooks under low
memory conditions, which results in no audio playback for the user.

Since some MediaTek platforms already have dedicated reserved memory
pools for the audio frontend, the plan is to enable this for all of
them. This requires device tree changes. As a fallback, reinstate the
original policy of pre-allocating audio buffers at probe time of the
reserved memory pool cannot be found or used.

This patch covers the MT8173, MT8183, MT8186 and MT8192 platforms for
now, the reason being that existing MediaTek platform drivers that
supported reserved memory were all platforms that mainly supported
ChromeOS, and is also the set of devices that I can verify.

Fixes: 32c9c06adb5b ("ASoC: mediatek: disable buffer pre-allocation")
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
Link: https://patch.msgid.link/20250612074901.4023253-7-wenst@chromium.org
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/mediatek/common/mtk-afe-platform-driver.c b/sound/soc/mediatek/common/mtk-afe-platform-driver.c
index 6b63305839414056f4f0086eb3d6d9fd4d9e348c..70fd05d5ff486c6da7e648eaef90e0a4f1a6567f 100644 (file)
--- a/sound/soc/mediatek/common/mtk-afe-platform-driver.c
+++ b/sound/soc/mediatek/common/mtk-afe-platform-driver.c
@@ -120,7 +120,9 @@ int mtk_afe_pcm_new(struct snd_soc_component *component,
        struct mtk_base_afe *afe = snd_soc_component_get_drvdata(component);
 
        size = afe->mtk_afe_hardware->buffer_bytes_max;
-       snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV, afe->dev, 0, size);
+       snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV, afe->dev,
+                                      afe->preallocate_buffers ? size : 0,
+                                      size);
 
        return 0;
 }

diff --git a/sound/soc/mediatek/common/mtk-base-afe.h b/sound/soc/mediatek/common/mtk-base-afe.h
index f51578b6c50a3567f0b1009403162681d312f8b4..a406f2e3e7a8786984ad89f4b1402d402a4e2923 100644 (file)
--- a/sound/soc/mediatek/common/mtk-base-afe.h
+++ b/sound/soc/mediatek/common/mtk-base-afe.h
@@ -117,6 +117,7 @@ struct mtk_base_afe {
        struct mtk_base_afe_irq *irqs;
        int irqs_size;
        int memif_32bit_supported;
+       bool preallocate_buffers;
 
        struct list_head sub_dais;
        struct snd_soc_dai_driver *dai_drivers;

diff --git a/sound/soc/mediatek/mt8173/mt8173-afe-pcm.c b/sound/soc/mediatek/mt8173/mt8173-afe-pcm.c
index 04ed0cfec1741ee2c2dddd39c6d7c27f65445eb7..f93d6348fdf89aead9321926169c57d5439e52a0 100644 (file)
--- a/sound/soc/mediatek/mt8173/mt8173-afe-pcm.c
+++ b/sound/soc/mediatek/mt8173/mt8173-afe-pcm.c
@@ -13,6 +13,7 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
+#include <linux/of_reserved_mem.h>
 #include <linux/dma-mapping.h>
 #include <linux/pm_runtime.h>
 #include <sound/soc.h>
@@ -1070,6 +1071,12 @@ static int mt8173_afe_pcm_dev_probe(struct platform_device *pdev)
 
        afe->dev = &pdev->dev;
 
+       ret = of_reserved_mem_device_init(&pdev->dev);
+       if (ret) {
+               dev_info(&pdev->dev, "no reserved memory found, pre-allocating buffers instead\n");
+               afe->preallocate_buffers = true;
+       }
+
        irq_id = platform_get_irq(pdev, 0);
        if (irq_id <= 0)
                return irq_id < 0 ? irq_id : -ENXIO;

diff --git a/sound/soc/mediatek/mt8183/mt8183-afe-pcm.c b/sound/soc/mediatek/mt8183/mt8183-afe-pcm.c
index e8884354995cb154b7e06e163fb502683df654a4..9b6b45c646e69ea5c0b51074fbd1454f99c066cf 100644 (file)
--- a/sound/soc/mediatek/mt8183/mt8183-afe-pcm.c
+++ b/sound/soc/mediatek/mt8183/mt8183-afe-pcm.c
@@ -10,6 +10,7 @@
 #include <linux/mfd/syscon.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
+#include <linux/of_reserved_mem.h>
 #include <linux/pm_runtime.h>
 #include <linux/reset.h>
 
@@ -777,6 +778,12 @@ static int mt8183_afe_pcm_dev_probe(struct platform_device *pdev)
        afe->dev = &pdev->dev;
        dev = afe->dev;
 
+       ret = of_reserved_mem_device_init(dev);
+       if (ret) {
+               dev_info(dev, "no reserved memory found, pre-allocating buffers instead\n");
+               afe->preallocate_buffers = true;
+       }
+
        /* initial audio related clock */
        ret = mt8183_init_clock(afe);
        if (ret) {

diff --git a/sound/soc/mediatek/mt8186/mt8186-afe-pcm.c b/sound/soc/mediatek/mt8186/mt8186-afe-pcm.c
index db7c93401bee69e3b2970ed52b736bc770394f54..c73b4664e53e1b9ce4188750d350abab352799eb 100644 (file)
--- a/sound/soc/mediatek/mt8186/mt8186-afe-pcm.c
+++ b/sound/soc/mediatek/mt8186/mt8186-afe-pcm.c
@@ -10,6 +10,7 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
+#include <linux/of_reserved_mem.h>
 #include <linux/pm_runtime.h>
 #include <linux/reset.h>
 #include <sound/soc.h>
@@ -2835,6 +2836,12 @@ static int mt8186_afe_pcm_dev_probe(struct platform_device *pdev)
        afe_priv = afe->platform_priv;
        afe->dev = &pdev->dev;
 
+       ret = of_reserved_mem_device_init(dev);
+       if (ret) {
+               dev_info(dev, "no reserved memory found, pre-allocating buffers instead\n");
+               afe->preallocate_buffers = true;
+       }
+
        afe->base_addr = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(afe->base_addr))
                return PTR_ERR(afe->base_addr);

diff --git a/sound/soc/mediatek/mt8192/mt8192-afe-pcm.c b/sound/soc/mediatek/mt8192/mt8192-afe-pcm.c
index fd6af74d7995793a63e019cbec2075ea09da2b65..3d32fe46118ece974063ba8fded34958289d5ba7 100644 (file)
--- a/sound/soc/mediatek/mt8192/mt8192-afe-pcm.c
+++ b/sound/soc/mediatek/mt8192/mt8192-afe-pcm.c
@@ -12,6 +12,7 @@
 #include <linux/mfd/syscon.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
+#include <linux/of_reserved_mem.h>
 #include <linux/pm_runtime.h>
 #include <linux/reset.h>
 #include <sound/soc.h>
@@ -2179,6 +2180,12 @@ static int mt8192_afe_pcm_dev_probe(struct platform_device *pdev)
 
        afe->dev = dev;
 
+       ret = of_reserved_mem_device_init(dev);
+       if (ret) {
+               dev_info(dev, "no reserved memory found, pre-allocating buffers instead\n");
+               afe->preallocate_buffers = true;
+       }
+
        /* init audio related clock */
        ret = mt8192_init_clock(afe);
        if (ret) {