Re: [PATCH next] phy: apple: atc: Actually check return value of devm_apple_tunable_parse

[Janne Grunau <j@jannau.net>]

On Sun, Jan 04, 2026 at 10:18:31PM +0100, Sven Peter wrote:
> Let's actually check the return value of devm_apple_tunable_parse
> instead of trying to check IS_ERR on a pointer to the return value which
> is always going to be valid. This prevent a oops when the tunables are
> invalid or when they don't exist:
> 
> [   42.819119] ------------[ cut here ]------------
> [   42.819121] WARNING: CPU: 6 PID: 88 at drivers/phy/apple/atc.c:2145 atcphy_mux_set+0xf60/0x1128 [phy_apple_atc]
> [   42.819302] CPU: 6 UID: 0 PID: 88 Comm: kworker/6:1 Tainted: G S                  6.18+unreleased-asahi #1 PREEMPTLAZY  Debian 6.18.2-0-1~exp1
> [   42.819311] Tainted: [S]=CPU_OUT_OF_SPEC
> [   42.819314] Hardware name: Apple Mac mini (M1, 2020) (DT)
> [   42.819316] Workqueue: events cd321x_update_work [tps6598x]
> [   42.819332] pstate: 81400009 (Nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
> [   42.819338] pc : atcphy_mux_set+0xf60/0x1128 [phy_apple_atc]
> [   42.819344] lr : atcphy_mux_set+0x30/0x1128 [phy_apple_atc]
> [   42.819348] sp : ffffc000813c7c00
> [   42.819350] x29: ffffc000813c7c00 x28: ffff800016babeb8 x27: ffff800016babc80
> [   42.819357] x26: 0000000000000001 x25: 0000000000000001 x24: 0000000000000000
> [   42.819364] x23: ffff800016babec0 x22: 00000000ffffffa1 x21: 0000000000000003
> [   42.819371] x20: ffff80000c1b3680 x19: ffff80000dcdd080 x18: 0000000000000000
> [   42.819376] x17: 0000000000000000 x16: ffffd42e6ede6e08 x15: 0000000000000000
> [   42.819382] x14: ffffd42e707b6980 x13: 0000000000025c68 x12: 726f703d54524f50
> [   42.819388] x11: 0000000000000040 x10: 0000000000000000 x9 : ffffd42e555ed9c0
> [   42.819394] x8 : 0000000000000006 x7 : ffff80000a000dd8 x6 : 0000000000000002
> [   42.819399] x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000001
> [   42.819404] x2 : 0000000000000005 x1 : 000000000000ff01 x0 : 0000000000000001
> [   42.819410] Call trace:
> [   42.819412]  atcphy_mux_set+0xf60/0x1128 [phy_apple_atc] (P)
> [   42.819419]  typec_mux_set+0x74/0xd8 [typec]
> [   42.819444]  cd321x_update_work+0x440/0x8a8 [tps6598x]
> [   42.819453]  process_one_work+0x170/0x3e0
> [   42.819466]  worker_thread+0x25c/0x390
> [   42.819473]  kthread+0x148/0x240
> [   42.819479]  ret_from_fork+0x10/0x20
> [   42.819488] ---[ end trace 0000000000000000 ]---
> 
> Reported-by: Thomas Glanzmann <thomas@glanzmann.de>
> Fixes: 8e98ca1e74db ("phy: apple: Add Apple Type-C PHY")
> Signed-off-by: Sven Peter <sven@kernel.org>
> ---
>  drivers/phy/apple/atc.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/phy/apple/atc.c b/drivers/phy/apple/atc.c
> index c8a58ee64b7aad3205df51cf16ae778471ad2c5d..716c1e70de38ca604803739fedaa543d91f7501b 100644
> --- a/drivers/phy/apple/atc.c
> +++ b/drivers/phy/apple/atc.c
> @@ -2178,10 +2178,10 @@ static int atcphy_load_tunables(struct apple_atcphy *atcphy)
>  	for (int i = 0; i < ARRAY_SIZE(tunables); i++) {
>  		*tunables[i].tunable = devm_apple_tunable_parse(
>  			atcphy->dev, atcphy->np, tunables[i].dt_name, tunables[i].res);
> -		if (IS_ERR(tunables[i].tunable)) {
> +		if (IS_ERR(*tunables[i].tunable)) {
>  			dev_err(atcphy->dev, "Failed to read tunable %s: %ld\n",
> -				tunables[i].dt_name, PTR_ERR(tunables[i].tunable));
> -			return PTR_ERR(tunables[i].tunable);
> +				tunables[i].dt_name, PTR_ERR(*tunables[i].tunable));
> +			return PTR_ERR(*tunables[i].tunable);
>  		}
>  	}

Reviewed-by: Janne Grunau <j@jannau.net>

Janne