From nobody Mon Feb 9 01:47:47 2026 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 E80CF1FD4 for ; Sun, 16 Nov 2025 15:56:00 +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=1763308562; cv=none; b=g7RUhYlfa6nQkrw/GyvfOONpMY1dZru82ZPLfmExESCTYCaf2k9Pi4JNv847g2QQ8vgYl8yFJQryomPHWbFqWkCRukIgEcqVCImp/JPLdhss+3CF+blhf3mV/0x8lqOJgTTqB1nxHKd5HJSuaaKEU9vi9CZLysIK/vpfDvDnOUo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763308562; c=relaxed/simple; bh=piiZABcIkPvCH85m5XqijCtUq+SBcVfDPS3VKibeIzs=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=NBiFXhaRg3eoU+iuZ/4RVzb1HjWsao3L7doUGEBZnbc89xsd1HbFhW2UgQla9Gb/9DVI5HHMJB6AWrR8G/EmphSOLH4zSgVzJG/e8xuHDarehpeMtUaF3aXt2GhA+px1Leg4XUb96yC73Ptbzow1uRG/Q7eBdJS0NNG77FJ0ulc= 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 1vKf6H-0006Dx-Vl; Sun, 16 Nov 2025 16:55:37 +0100 Received: from moin.white.stw.pengutronix.de ([2a0a:edc0:0:b01:1d::7b] helo=bjornoya.blackshift.org) 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 1vKf6G-000lfs-22; Sun, 16 Nov 2025 16:55:36 +0100 Received: from hardanger.blackshift.org (p54b152ce.dip0.t-ipconnect.de [84.177.82.206]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) (Authenticated sender: mkl-all@blackshift.org) by smtp.blackshift.org (Postfix) with ESMTPSA id 514694A0D69; Sun, 16 Nov 2025 15:55:36 +0000 (UTC) From: Marc Kleine-Budde Date: Sun, 16 Nov 2025 16:55:26 +0100 Subject: [PATCH can] can: sun4i_can: sun4i_can_interrupt(): fix max irq loop handling Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20251116-sun4i-fix-loop-v1-1-3d76d3f81950@pengutronix.de> X-B4-Tracking: v=1; b=H4sIAO7zGWkC/x2MQQqAIBAAvyJ7bqGVFOor0cFsq4XQUIpA+nvSc RhmCmROwhkGVSDxLVliqECNAr+7sDHKUhl0qw0RWcxX6ARXefCI8cRVW2M1zdb1PdToTFzdPxz BuwDT+36eMwq4ZQAAAA== X-Change-ID: 20251116-sun4i-fix-loop-f265621b6a99 To: Vincent Mailhol , Chen-Yu Tsai , Jernej Skrabec , Samuel Holland , Gerhard Bertelsmann , Maxime Ripard Cc: kernel@pengutronix.de, linux-can@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org, stable@vger.kernel.org, =?utf-8?q?Thomas_M=C3=BChlbacher?= , Marc Kleine-Budde X-Mailer: b4 0.15-dev-a6db3 X-Developer-Signature: v=1; a=openpgp-sha256; l=1639; i=mkl@pengutronix.de; h=from:subject:message-id; bh=piiZABcIkPvCH85m5XqijCtUq+SBcVfDPS3VKibeIzs=; b=owEBbQGS/pANAwAKAQx0Zd/5kJGcAcsmYgBpGfP1O2x1G+zpjpRJjKaXo54TmBgwthKqzmzGq fbf/sJiZTiJATMEAAEKAB0WIQSf+wzYr2eoX/wVbPMMdGXf+ZCRnAUCaRnz9QAKCRAMdGXf+ZCR nJaoB/4rjKBfJJSDQ4zQgHs1guSEV6YizBk5eiUmnvir8afm7j3J8t8qoG8bzJM8kaQ41q21AtI 7NqTPanSTdclNme3HWvizX4SWZFi4TRxMIy4Mw+3sO3nuXCtVN+vwr6pBKhqQZELQ8fPrOMvZli xmK/aJhJKiPZp2vm8raNr5WhWDPrTtVkftP2TM8MnYCLbNG2aCPbxjb55KPpc4EMxvQUkdjdyCp eNzWiqHIMRpjXWSwVtqhAy1IUqjm/m03ywNMA+kar6PQCgEwsSGgTBDD9Vg/hbQMWp/42Z5QDTT K81IIXmX1yuSs0lberkstH0VPRbX/9FvRoIE8RPdQ23NC+89 X-Developer-Key: i=mkl@pengutronix.de; a=openpgp; fpr=C1400BA0B3989E6FBC7D5B5C2B5EE211C58AEA54 X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: mkl@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 Reading the interrupt register `SUN4I_REG_INT_ADDR` causes all of its bits to be reset. If we ever reach the condition of handling more than `SUN4I_CAN_MAX_IRQ` IRQs, we will have read the register and reset all its bits but without actually handling the interrupt inside of the loop body. This may, among other issues, cause us to never `netif_wake_queue()` again after a transmission interrupt. Fixes: 0738eff14d81 ("can: Allwinner A10/A20 CAN Controller support - Kerne= l module") Cc: stable@vger.kernel.org Co-developed-by: Thomas M=C3=BChlbacher Signed-off-by: Thomas M=C3=BChlbacher Signed-off-by: Marc Kleine-Budde Acked-by: Jernej Skrabec --- I've ported the fix from the sja1000 driver to the sun4i_can, which based on the sja1000 driver. --- drivers/net/can/sun4i_can.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/can/sun4i_can.c b/drivers/net/can/sun4i_can.c index 53bfd873de9b..0a7ba0942839 100644 --- a/drivers/net/can/sun4i_can.c +++ b/drivers/net/can/sun4i_can.c @@ -657,8 +657,8 @@ static irqreturn_t sun4i_can_interrupt(int irq, void *d= ev_id) u8 isrc, status; int n =3D 0; =20 - while ((isrc =3D readl(priv->base + SUN4I_REG_INT_ADDR)) && - (n < SUN4I_CAN_MAX_IRQ)) { + while ((n < SUN4I_CAN_MAX_IRQ) && + (isrc =3D readl(priv->base + SUN4I_REG_INT_ADDR))) { n++; status =3D readl(priv->base + SUN4I_REG_STA_ADDR); =20 --- base-commit: 5442a9da69789741bfda39f34ee7f69552bf0c56 change-id: 20251116-sun4i-fix-loop-f265621b6a99 Best regards, -- =20 Marc Kleine-Budde