From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E8F061CAA4; Wed, 4 Jun 2025 00:51:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748998314; cv=none; b=M/tsVoDnzBwA+H2tpkZiQ7AWIdbFctuNtnbfzY7emMTGfNQzMzXHu0qsHj7+yF7gNl0/ANqqOluqYrDJYeVsFkeRwLK+kfdhJ9i1q3gCSoy/7Bs1ma4YZlB83wQdVt2wvXnrA5siOvolfnSbuD1I2udcmvorRB054p082f/BT4U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748998314; c=relaxed/simple; bh=KQRPWiVIirFM5HlqIdlbktPx3zZ+EkbTpPF8djX4G4I=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=X4BY/fNDD6+KJj6zEjR7AZusU3+HrgtuI4Uwcwf5Zym9aM931mfUF1Pe9scoptgOhSN2U4LXxDPeNPYHwweQoF2AckdMIp+dzmPpeqbiu6WnU9rDCs3Xua9A3oX5uEM+iDGTn4DF+r7+hssQLTDlS6SQLB/E29Uoy5KCX8MAge0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=F1+zSFVB; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="F1+zSFVB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D886AC4CEF1; Wed, 4 Jun 2025 00:51:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1748998313; bh=KQRPWiVIirFM5HlqIdlbktPx3zZ+EkbTpPF8djX4G4I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=F1+zSFVBNfUIC9vLfCMo8uqHv2WsFrb2wvRUwcgKSUsIEvZ+/Y4xEIJQ1kjnVslUc 4R4CoRqEG6uOf6njrxf9YkJfBui2tp/hf766naypq1FwskHmawSOAjShiz1cn4mvOW W7QqP8MHyjVW6p+HqpFNBIEjN31PjhfFUxUXslop0J3yAIbuigQ9wJdw90a9NkbVev hD0hHNe3GrgAEgszqIUCAgA2X1toNI0F1XZOBxqiY/YnoBX5PHbhVxLogMrpTEiarg ob5RbAyQFQi+mf6d8Z/jofMUXS/RBHOc+mtJoQzbiikBk9Rt5NbtxCpBQR4LaKqGGU gCHe61RIZXTQA== From: Sasha Levin To: patches@lists.linux.dev, stable@vger.kernel.org Cc: Frank Wunderlich , Jakub Kicinski , Sasha Levin , daniel@makrotopia.org, dqfext@gmail.com, SkyLake.Huang@mediatek.com, matthias.bgg@gmail.com, angelogioacchino.delregno@collabora.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org Subject: [PATCH AUTOSEL 6.15 029/118] net: phy: mediatek: do not require syscon compatible for pio property Date: Tue, 3 Jun 2025 20:49:20 -0400 Message-Id: <20250604005049.4147522-29-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250604005049.4147522-1-sashal@kernel.org> References: <20250604005049.4147522-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.15 Content-Transfer-Encoding: 8bit From: Frank Wunderlich [ Upstream commit 15d7b3dfafa98270eade6c77d2336790dde0a40d ] Current implementation requires syscon compatible for pio property which is used for driving the switch leds on mt7988. Replace syscon_regmap_lookup_by_phandle with of_parse_phandle and device_node_to_regmap to get the regmap already assigned by pinctrl driver. Signed-off-by: Frank Wunderlich Link: https://patch.msgid.link/20250510174933.154589-1-linux@fw-web.de Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- **YES** This commit should be backported to stable kernel trees. ## Analysis ### Core Issue Being Fixed The commit addresses a **device tree compatibility problem** in the MediaTek MT7988 PHY driver. The original code used `syscon_regmap_lookup_by_phandle()` which **requires** the target device node to have a "syscon" compatible string. This created an artificial requirement that forced users to modify their device trees even when the pinctrl driver already provided the necessary regmap. ### Code Changes Analysis The change is minimal but significant: ```c // OLD: Forces syscon compatible requirement regmap = syscon_regmap_lookup_by_phandle(np, "mediatek,pio"); // NEW: Works with any regmap provider pio_np = of_parse_phandle(np, "mediatek,pio", 0); regmap = device_node_to_regmap(pio_np); of_node_put(pio_np); ``` **Key differences:** - `syscon_regmap_lookup_by_phandle()` requires "syscon" compatible - `device_node_to_regmap()` works with any device that has registered a regmap - Proper error handling maintained with `of_node_put()` ### Why This Should Be Backported **1. Fixes Real User Issues:** - MT7988 hardware is actively deployed (BananaPi R4, networking devices) - Users cannot use PHY LED functionality without modifying device trees - This affects real hardware in production, not just development boards **2. Low Risk Change:** - Only 9 insertions, 1 deletion - No functional behavior change - same register access, same error paths - Uses well-established kernel APIs - **Backward compatible:** Still works with DTs that have syscon compatible - **Forward compatible:** Also works with DTs that don't have syscon compatible **3. High Impact Fix:** - Removes artificial device tree constraints - Enables legitimate hardware configurations without DT hacks - Prevents fragmentation of MT7988 ecosystem across kernel versions - LED functionality is important for networking hardware visibility **4. Fits Stable Criteria:** - Fixes important functionality for users - Does not introduce new features - No architectural changes - Confined to one driver/subsystem - Minimal regression risk ### Comparison to Similar Commits Looking at the historical examples provided, this commit is similar to "clk: mediatek: Get regmap without syscon compatible check" which also moved from `syscon_node_to_regmap()` to `device_node_to_regmap()` for the same compatibility reasons. The pattern of removing unnecessary syscon requirements is well-established and safe. ### Real-World Impact Without this fix, users with legitimate device trees (where pinctrl doesn't have syscon compatible) cannot use MT7988 PHY LED functionality. This forces them to either: 1. Patch their device trees (not always possible in production) 2. Use older kernel versions 3. Lose LED functionality entirely The commit solves a **compatibility regression** rather than adding new functionality, making it an ideal stable backport candidate. drivers/net/phy/mediatek/mtk-ge-soc.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/net/phy/mediatek/mtk-ge-soc.c b/drivers/net/phy/mediatek/mtk-ge-soc.c index 175cf5239bba8..21975ef946d5b 100644 --- a/drivers/net/phy/mediatek/mtk-ge-soc.c +++ b/drivers/net/phy/mediatek/mtk-ge-soc.c @@ -7,6 +7,7 @@ #include #include #include +#include #include "../phylib.h" #include "mtk.h" @@ -1319,6 +1320,7 @@ static int mt7988_phy_probe_shared(struct phy_device *phydev) { struct device_node *np = dev_of_node(&phydev->mdio.bus->dev); struct mtk_socphy_shared *shared = phy_package_get_priv(phydev); + struct device_node *pio_np; struct regmap *regmap; u32 reg; int ret; @@ -1336,7 +1338,13 @@ static int mt7988_phy_probe_shared(struct phy_device *phydev) * The 4 bits in TPBANK0 are kept as package shared data and are used to * set LED polarity for each of the LED0. */ - regmap = syscon_regmap_lookup_by_phandle(np, "mediatek,pio"); + pio_np = of_parse_phandle(np, "mediatek,pio", 0); + if (!pio_np) + return -ENODEV; + + regmap = device_node_to_regmap(pio_np); + of_node_put(pio_np); + if (IS_ERR(regmap)) return PTR_ERR(regmap); -- 2.39.5