From nobody Tue Oct 7 07:07:39 2025 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (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 1D76723E350 for ; Mon, 14 Jul 2025 09:52:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752486774; cv=none; b=QEwGs2zVO/IGgqTkS4qFtSuQJx9LW5fZt7Uq3I74xKTwRatlN3T/CeLQh5aDhGgtXF4sm75zLJLLrF2IEln6pv/Xhmn0jHUqs7pLqNv7QOi2HdnAEN0R5q72SmC8oQWjM9TXl1W/UZcAemzjDqhXzHhxuK5RkR9wtGXqgbT9jZ8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752486774; c=relaxed/simple; bh=ithmMftiixNrY/53uTAsUFJyE6dTO04R0+mJgZDYPZk=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=bXW2+knHXOwT06Q67tBOTWtKrZVaeWEQYHIEHdm5+W/9IQ5vCIBJDOdY3og5VJSXMuA6jOsz9H7qIdHOnpsI6i2YTSq87+RH2c57/BShASbVQfGoklx4KBuXoJMnsI29QivFdJxEwb95lmszC+J7ne3E/p2E9UbhLq1ldyFJiDI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.201.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1ubFrX-0006Hr-1I; Mon, 14 Jul 2025 11:52:43 +0200 Received: from dude04.red.stw.pengutronix.de ([2a0a:edc0:0:1101:1d::ac]) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1ubFrV-008OKX-2A; Mon, 14 Jul 2025 11:52:41 +0200 Received: from ore by dude04.red.stw.pengutronix.de with local (Exim 4.96) (envelope-from ) id 1ubFrV-00BmIG-1v; Mon, 14 Jul 2025 11:52:41 +0200 From: Oleksij Rempel To: Andrew Lunn , Heiner Kallweit , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: Oleksij Rempel , kernel@pengutronix.de, linux-kernel@vger.kernel.org, Russell King , netdev@vger.kernel.org, Andre Edich , Lukas Wunner Subject: [PATCH net v4 2/3] net: phy: allow drivers to disable polling via get_next_update_time() Date: Mon, 14 Jul 2025 11:52:39 +0200 Message-Id: <20250714095240.2807202-3-o.rempel@pengutronix.de> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250714095240.2807202-1-o.rempel@pengutronix.de> References: <20250714095240.2807202-1-o.rempel@pengutronix.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: ore@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Some PHY drivers can reliably report link-down events via IRQs, but may fail to generate reliable link-up IRQs. To support such cases, polling is often needed - but only selectively. Extend get_next_update_time() so drivers can return PHY_STATE_IRQ to indicate that polling is not needed and IRQs are sufficient. This allows finer control over PHY state machine behavior. Introduce PHY_STATE_IRQ (UINT_MAX) as a sentinel value, and move PHY_STATE_TIME to phy.h to allow consistent use across the codebase. This change complements the previous patch enabling polling when get_next_update_time() is present. Signed-off-by: Oleksij Rempel --- changes v4: - address -Wformat-security for WARN_ONCE() changes v3: - handle conflicting configuration if update_stats are supported changes v2: - this patch is added --- drivers/net/phy/phy.c | 27 ++++++++++++++++++++------- include/linux/phy.h | 15 ++++++++++++++- 2 files changed, 34 insertions(+), 8 deletions(-) diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c index 13df28445f02..8f6d5a95c777 100644 --- a/drivers/net/phy/phy.c +++ b/drivers/net/phy/phy.c @@ -39,8 +39,6 @@ #include "phylib-internal.h" #include "phy-caps.h" =20 -#define PHY_STATE_TIME HZ - #define PHY_STATE_STR(_state) \ case PHY_##_state: \ return __stringify(_state); \ @@ -1575,16 +1573,31 @@ static enum phy_state_work _phy_state_machine(struc= t phy_device *phydev) phy_process_state_change(phydev, old_state); =20 /* Only re-schedule a PHY state machine change if we are polling the - * PHY, if PHY_MAC_INTERRUPT is set, then we will be moving - * between states from phy_mac_interrupt(). + * PHY. If PHY_MAC_INTERRUPT is set or get_next_update_time() returns + * PHY_STATE_IRQ, then we rely on interrupts for state changes. * * In state PHY_HALTED the PHY gets suspended, so rescheduling the * state machine would be pointless and possibly error prone when * called from phy_disconnect() synchronously. */ - if (phy_polling_mode(phydev) && phy_is_started(phydev)) - phy_queue_state_machine(phydev, - phy_get_next_update_time(phydev)); + if (phy_polling_mode(phydev) && phy_is_started(phydev)) { + unsigned int next_time =3D phy_get_next_update_time(phydev); + + if (next_time =3D=3D PHY_STATE_IRQ) { + /* A driver requesting IRQ mode while also needing + * polling for stats has a conflicting configuration. + * Warn about this buggy driver and fall back to + * polling to ensure stats are updated. + */ + if (phydev->drv->update_stats) { + WARN_ONCE(1, "phy: %s: driver requested IRQ mode but needs polling for= stats\n", + phydev_name(phydev)); + phy_queue_state_machine(phydev, PHY_STATE_TIME); + } + } else { + phy_queue_state_machine(phydev, next_time); + } + } =20 return state_work; } diff --git a/include/linux/phy.h b/include/linux/phy.h index 2688c0435b9b..673477700416 100644 --- a/include/linux/phy.h +++ b/include/linux/phy.h @@ -66,6 +66,11 @@ extern const int phy_basic_ports_array[3]; #define PHY_ALWAYS_CALL_SUSPEND 0x00000008 #define MDIO_DEVICE_IS_PHY 0x80000000 =20 +/* Default polling interval */ +#define PHY_STATE_TIME HZ +/* disable polling, rely on IRQs */ +#define PHY_STATE_IRQ UINT_MAX + /** * enum phy_interface_t - Interface Mode definitions * @@ -1261,7 +1266,15 @@ struct phy_driver { * dynamically adjust polling intervals based on link state or other * conditions. * - * Returns the time in jiffies until the next update event. + * Returning PHY_STATE_IRQ disables polling for link state changes, + * indicating that the driver relies solely on IRQs for this purpose. + * Note that polling may continue at a default rate if needed for + * other callbacks like update_stats(). Requesting IRQ mode while + * implementing update_stats() is considered a driver bug and will + * trigger a kernel warning. + * + * Returns the time in jiffies until the next update event, or + * PHY_STATE_IRQ to disable polling. */ unsigned int (*get_next_update_time)(struct phy_device *dev); }; --=20 2.39.5