FAILED: patch "[PATCH] can: rcar_canfd: change the initializing flow for clocks and" failed to apply to 5.15-stable tree

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x bef9004c5b91debfceaea2841855a4ebe81ff2b3
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026080505-hazard-resale-b8c1@gregkh' --subject-prefix 'PATCH 5.15.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From bef9004c5b91debfceaea2841855a4ebe81ff2b3 Mon Sep 17 00:00:00 2001
From: Tu Nguyen <[email protected]>
Date: Thu, 25 Jun 2026 14:51:51 +0100
Subject: [PATCH] can: rcar_canfd: change the initializing flow for clocks and
 resets

Testing CANFD on RZ/G3E shows that many registers do not reset to their
initial values with the current flow of deasserting resets first and then
enabling clocks.

Based on the HW manual, clocks should be supplied first and the
resets deasserted afterward.

 section 7.4.3 Procedure for Activating Modules: RZ/G2L
 section 4.4.9.3 Procedure for Starting up Units: RZ/G3E

So, update the order of the initializing flow for resets and clocks
to match the hardware manual, resetting all CANFD registers to their
initial values. Also update rcar_canfd_global_deinit() to assert
resets before disabling clocks, so the teardown path mirrors the new
init ordering.

Fixes: 76e9353a80e9 ("can: rcar_canfd: Add support for RZ/G2L family")
Signed-off-by: Tu Nguyen <[email protected]>
Signed-off-by: Biju Das <[email protected]>
Tested-by: Claudiu Beznea <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: Vincent Mailhol <[email protected]>
Link: https://patch.msgid.link/[email protected]
Cc: [email protected]
Signed-off-by: Marc Kleine-Budde <[email protected]>

diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c
index eaf8cac78038..fcc37b73ed43 100644
--- a/drivers/net/can/rcar/rcar_canfd.c
+++ b/drivers/net/can/rcar/rcar_canfd.c
@@ -2003,20 +2003,12 @@ static int rcar_canfd_global_init(struct rcar_canfd_global *gpriv)
 	u32 ch, sts;
 	int err;
 
-	err = reset_control_reset(gpriv->rstc1);
-	if (err)
-		return err;
-
-	err = reset_control_reset(gpriv->rstc2);
-	if (err)
-		goto fail_reset1;
-
 	/* Enable peripheral clock for register access */
 	err = clk_prepare_enable(gpriv->clkp);
 	if (err) {
 		dev_err(dev, "failed to enable peripheral clock: %pe\n",
 			ERR_PTR(err));
-		goto fail_reset2;
+		return err;
 	}
 
 	/* Enable RAM clock */
@@ -2027,10 +2019,18 @@ static int rcar_canfd_global_init(struct rcar_canfd_global *gpriv)
 		goto fail_clk;
 	}
 
+	err = reset_control_reset(gpriv->rstc1);
+	if (err)
+		goto fail_ram_clk;
+
+	err = reset_control_reset(gpriv->rstc2);
+	if (err)
+		goto fail_reset1;
+
 	err = rcar_canfd_reset_controller(gpriv);
 	if (err) {
 		dev_err(dev, "reset controller failed: %pe\n", ERR_PTR(err));
-		goto fail_ram_clk;
+		goto fail_reset2;
 	}
 
 	/* Controller in Global reset & Channel reset mode */
@@ -2068,14 +2068,14 @@ static int rcar_canfd_global_init(struct rcar_canfd_global *gpriv)
 
 fail_mode:
 	rcar_canfd_disable_global_interrupts(gpriv);
-fail_ram_clk:
-	clk_disable_unprepare(gpriv->clk_ram);
-fail_clk:
-	clk_disable_unprepare(gpriv->clkp);
 fail_reset2:
 	reset_control_assert(gpriv->rstc2);
 fail_reset1:
 	reset_control_assert(gpriv->rstc1);
+fail_ram_clk:
+	clk_disable_unprepare(gpriv->clk_ram);
+fail_clk:
+	clk_disable_unprepare(gpriv->clkp);
 	return err;
 }
 
@@ -2090,10 +2090,10 @@ static void rcar_canfd_global_deinit(struct rcar_canfd_global *gpriv, bool full)
 		rcar_canfd_set_bit(gpriv->base, RCANFD_GCTR, RCANFD_GCTR_GSLPR);
 	}
 
-	clk_disable_unprepare(gpriv->clk_ram);
-	clk_disable_unprepare(gpriv->clkp);
 	reset_control_assert(gpriv->rstc2);
 	reset_control_assert(gpriv->rstc1);
+	clk_disable_unprepare(gpriv->clk_ram);
+	clk_disable_unprepare(gpriv->clkp);
 }
 
 static int rcar_canfd_probe(struct platform_device *pdev)