Subject: [PATCH] mmc: dw_mmc-rockchip: Add missing private data for very old controllers

From: Heiko Stuebner <[email-masked]>
Date: Fri, 22 May 2026 20:43:07 +0200

The really old controllers (rk2928, rk3066, rk3188) do not support UHS
speeds at all, and thus never handled phase data.

For that reason it never had a parse_dt callback and no driver private
data at all.

Commit ff6f0286c896 ("mmc: dw_mmc-rockchip: Add memory clock auto-gating
support") makes the private data sort of mandatory, because the init
function checks whether phases are configured internally or through the
clock controller.

This results in the old SoCs then experiencing NULL-pointer dereferences
when they try to access that private-data struct.

While we could have if (priv) conditionals in all places, it's way less
cluttery to just give the old types their private-data struct.

Fixes: ff6f0286c896 ("mmc: dw_mmc-rockchip: Add memory clock auto-gating support")
Cc: [email-masked]
Signed-off-by: Heiko Stuebner <[email-masked]>
---
 drivers/mmc/host/dw_mmc-rockchip.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/mmc/host/dw_mmc-rockchip.c b/drivers/mmc/host/dw_mmc-rockchip.c
index c6eece4ec3fd..75c82ff20f17 100644
--- a/drivers/mmc/host/dw_mmc-rockchip.c
+++ b/drivers/mmc/host/dw_mmc-rockchip.c
@@ -441,6 +441,22 @@ static int dw_mci_common_parse_dt(struct dw_mci *host)
 	return 0;
 }
 
+static int dw_mci_rk2928_parse_dt(struct dw_mci *host)
+{
+	struct dw_mci_rockchip_priv_data *priv;
+	int err;
+
+	err = dw_mci_common_parse_dt(host);
+	if (err)
+		return err;
+
+	priv = host->priv;
+
+	priv->internal_phase = false;
+
+	return 0;
+}
+
 static int dw_mci_rk3288_parse_dt(struct dw_mci *host)
 {
 	struct dw_mci_rockchip_priv_data *priv;
@@ -514,6 +530,7 @@ static int dw_mci_rockchip_init(struct dw_mci *host)
 
 static const struct dw_mci_drv_data rk2928_drv_data = {
 	.init			= dw_mci_rockchip_init,
+	.parse_dt		= dw_mci_rk2928_parse_dt,
 };
 
 static const struct dw_mci_drv_data rk3288_drv_data = {
-- 
2.47.3