[PATCH v2 2/4] mmc: meson-gx: enable the bus pipeline clock on T7
From: Lucas Tanure <hidden>
Date: 2026-09-05 15:32:46
Also in:
linux-amlogic, linux-arm-kernel, linux-clk, linux-mmc, lkml
Subsystem:
arm/amlogic meson soc support, multimedia card (mmc), secure digital (sd) and sdio subsystem, the rest · Maintainers:
Neil Armstrong, Kevin Hilman, Ulf Hansson, Linus Torvalds
On the T7 SoC, the bus path between the SD/eMMC controllers and the NIC_MATRIX fabric goes through a pipeline stage inserted by the hardware design to help timing closure. The stage has its own gate clock and, when that clock is disabled, a controller that starts a DMA transfer can never complete it, hanging the storage devices and, from there, the whole system. Add a dedicated match data for the amlogic,t7-mmc compatible that makes the driver claim and enable the "pipeline" clock for as long as the device is bound. The clock is deliberately not optional: the hardware cannot do DMA without it, and failing the probe with a clear error is preferable to booting and hitting an undiagnosable DMA hang later. Assisted-by: Claude:claude-fable-5 Signed-off-by: Lucas Tanure <redacted> --- drivers/mmc/host/meson-gx-mmc.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)
diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index 694bb443d5f3..c0f1e929fc13 100644
--- a/drivers/mmc/host/meson-gx-mmc.c
+++ b/drivers/mmc/host/meson-gx-mmc.c@@ -139,6 +139,7 @@ struct meson_mmc_data { unsigned int always_on; unsigned int adjust; unsigned int irq_sdio_sleep; + bool has_pipeline_clk; }; struct sd_emmc_desc {
@@ -1204,6 +1205,15 @@ static int meson_mmc_probe(struct platform_device *pdev) if (IS_ERR(core_clk)) return PTR_ERR(core_clk); + if (host->data->has_pipeline_clk) { + struct clk *pipe_clk; + + pipe_clk = devm_clk_get_enabled(&pdev->dev, "pipeline"); + if (IS_ERR(pipe_clk)) + return dev_err_probe(&pdev->dev, PTR_ERR(pipe_clk), + "missing pipeline clock\n"); + } + ret = meson_mmc_clk_init(host); if (ret) return ret;
@@ -1322,12 +1332,22 @@ static const struct meson_mmc_data meson_axg_data = { .irq_sdio_sleep = CLK_V3_IRQ_SDIO_SLEEP, }; +static const struct meson_mmc_data meson_t7_data = { + .tx_delay_mask = CLK_V3_TX_DELAY_MASK, + .rx_delay_mask = CLK_V3_RX_DELAY_MASK, + .always_on = CLK_V3_ALWAYS_ON, + .adjust = SD_EMMC_V3_ADJUST, + .irq_sdio_sleep = CLK_V3_IRQ_SDIO_SLEEP, + .has_pipeline_clk = true, +}; + static const struct of_device_id meson_mmc_of_match[] = { { .compatible = "amlogic,meson-gx-mmc", .data = &meson_gx_data }, { .compatible = "amlogic,meson-gxbb-mmc", .data = &meson_gx_data }, { .compatible = "amlogic,meson-gxl-mmc", .data = &meson_gx_data }, { .compatible = "amlogic,meson-gxm-mmc", .data = &meson_gx_data }, { .compatible = "amlogic,meson-axg-mmc", .data = &meson_axg_data }, + { .compatible = "amlogic,t7-mmc", .data = &meson_t7_data }, {} }; MODULE_DEVICE_TABLE(of, meson_mmc_of_match);
--
2.55.0