From 2519439b4b5f6ee95879b1a44fc373127291b1e4 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Wed, 2 Sep 2026 09:55:59 +0200 Subject: [PATCH] ASoC: ux500: Program the MSP FIFO watermarks The DMA engine is configured for four-element bursts, but the MSP driver never programs the FIFO watermark register and instead depends on its previous or reset value. The DB8500 DMA request protocol requires the peripheral watermark to match the DMA packet size. Program four-element receive and transmit watermarks when configuring the first direction, before enabling MSP DMA requests. Fixes: 3592b7f69a54 ("ASoC: Ux500: Add MSP I2S-driver") Assisted-by: LLM Signed-off-by: Linus Walleij Link: https://patch.msgid.link/20260902-ux500-msp-fixes-v2-9-4b60b002d55a@kernel.org Signed-off-by: Mark Brown --- sound/soc/ux500/ux500_msp_i2s.c | 2 ++ sound/soc/ux500/ux500_msp_i2s.h | 5 +++++ 2 files changed, 7 insertions(+) diff --git a/sound/soc/ux500/ux500_msp_i2s.c b/sound/soc/ux500/ux500_msp_i2s.c index 43dc9b3aa4ef..683b485fb570 100644 --- a/sound/soc/ux500/ux500_msp_i2s.c +++ b/sound/soc/ux500/ux500_msp_i2s.c @@ -507,6 +507,8 @@ int ux500_msp_i2s_open(struct ux500_msp *msp, old_reg &= ~mask; new_reg |= old_reg; writel(new_reg, msp->registers + MSP_GCR); + writel(MSP_WMRK_TX_4_ELEMENTS | MSP_WMRK_RX_4_ELEMENTS, + msp->registers + MSP_WMRK); } res = enable_msp(msp, config, first); diff --git a/sound/soc/ux500/ux500_msp_i2s.h b/sound/soc/ux500/ux500_msp_i2s.h index 17b5c37a7e5d..2bf2699bdc49 100644 --- a/sound/soc/ux500/ux500_msp_i2s.h +++ b/sound/soc/ux500/ux500_msp_i2s.h @@ -62,6 +62,7 @@ enum msp_direction { #define MSP_SRG 0x10 #define MSP_FLR 0x14 #define MSP_DMACR 0x18 +#define MSP_WMRK 0x1c #define MSP_IMSC 0x20 #define MSP_RIS 0x24 @@ -228,6 +229,10 @@ enum msp_direction { #define RDMAE_SHIFT 0 #define TDMAE_SHIFT 1 +/* FIFO watermark register */ +#define MSP_WMRK_RX_4_ELEMENTS BIT(0) +#define MSP_WMRK_TX_4_ELEMENTS BIT(3) + /* Interrupt Register */ #define RX_SERVICE_INT BIT(0) #define RX_OVERRUN_ERROR_INT BIT(1)