From: Kaustabh Chakraborty <kauschluss@disroot.org>
To: Ulf Hansson <ulfh@kernel.org>, Rob Herring <robh@kernel.org>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Conor Dooley <conor+dt@kernel.org>,
Jaehoon Chung <jh80.chung@samsung.com>,
Shawn Lin <shawn.lin@rock-chips.com>,
Krzysztof Kozlowski <krzk@kernel.org>,
Alim Akhtar <alim.akhtar@samsung.com>
Cc: linux-mmc@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-samsung-soc@vger.kernel.org,
Kaustabh Chakraborty <kauschluss@disroot.org>
Subject: [PATCH v3 2/2] mmc: dw_mmc: exynos: increase DMA threshold value for exynos7870
Date: Wed, 15 Apr 2026 20:32:09 +0530 [thread overview]
Message-ID: <20260415-dwmmc-dma-thr-v3-2-31014d36b6ee@disroot.org> (raw)
In-Reply-To: <20260415-dwmmc-dma-thr-v3-0-31014d36b6ee@disroot.org>
Exynos 7870 compatible controllers, such as SDIO ones are not able to
perform DMA transfers for small sizes of data (~16 to ~512 bytes),
resulting in cache issues in subsequent transfers. Increase the DMA
transfer threshold to 512 to allow the shorter transfers to take place,
bypassing DMA.
Signed-off-by: Kaustabh Chakraborty <kauschluss@disroot.org>
---
drivers/mmc/host/dw_mmc-exynos.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
index 261344d3a8cfe..4b76b997ddc15 100644
--- a/drivers/mmc/host/dw_mmc-exynos.c
+++ b/drivers/mmc/host/dw_mmc-exynos.c
@@ -141,6 +141,7 @@ static int dw_mci_exynos_priv_init(struct dw_mci *host)
priv->ctrl_type == DW_MCI_TYPE_EXYNOS7870_SMU) {
/* Quirk needed for certain Exynos SoCs */
host->quirks |= DW_MMC_QUIRK_FIFO64_32;
+ host->dma_threshold = 512;
}
if (priv->ctrl_type == DW_MCI_TYPE_ARTPEC8) {
--
2.53.0
next prev parent reply other threads:[~2026-04-15 15:03 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-15 15:02 [PATCH v3 0/2] Configuring DMA threshold value for DW-MMC controllers Kaustabh Chakraborty
2026-04-15 15:02 ` [PATCH v3 1/2] mmc: dw_mmc: implement option for configuring DMA threshold Kaustabh Chakraborty
2026-04-16 0:27 ` Shawn Lin
2026-04-15 15:02 ` Kaustabh Chakraborty [this message]
2026-04-16 0:29 ` [PATCH v3 2/2] mmc: dw_mmc: exynos: increase DMA threshold value for exynos7870 Shawn Lin
2026-05-07 14:28 ` [PATCH v3 0/2] Configuring DMA threshold value for DW-MMC controllers Kaustabh Chakraborty
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