linux-kernel - [patch 17/35] net: sun3lance: Remove redundant checks in interrupt handler

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Message-Id: <20200927194921.547895614@linutronix.de>
Date:   Sun, 27 Sep 2020 21:49:03 +0200
From:   Thomas Gleixner <tglx@...utronix.de>
To:     LKML <linux-kernel@...r.kernel.org>
Cc:     Peter Zijlstra <peterz@...radead.org>,
        Linus Torvalds <torvalds@...uxfoundation.org>,
        Paul McKenney <paulmck@...nel.org>,
        Matthew Wilcox <willy@...radead.org>,
        Sebastian Andrzej Siewior <bigeasy@...utronix.de>,
        "David S. Miller" <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>, netdev@...r.kernel.org,
        Christian Benvenuti <benve@...co.com>,
        Govindarajulu Varadarajan <_govind@....com>,
        Dave Miller <davem@...emloft.net>,
        Jonathan Corbet <corbet@....net>,
        Mauro Carvalho Chehab <mchehab+huawei@...nel.org>,
        linux-doc@...r.kernel.org,
        Luc Van Oostenryck <luc.vanoostenryck@...il.com>,
        Jay Cliburn <jcliburn@...il.com>,
        Chris Snook <chris.snook@...il.com>,
        Vishal Kulkarni <vishal@...lsio.com>,
        Jeff Kirsher <jeffrey.t.kirsher@...el.com>,
        intel-wired-lan@...ts.osuosl.org,
        Shannon Nelson <snelson@...sando.io>,
        Pensando Drivers <drivers@...sando.io>,
        Andrew Lunn <andrew@...n.ch>,
        Heiner Kallweit <hkallweit1@...il.com>,
        Russell King <linux@...linux.org.uk>,
        Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
        Solarflare linux maintainers <linux-net-drivers@...arflare.com>,
        Edward Cree <ecree@...arflare.com>,
        Martin Habets <mhabets@...arflare.com>,
        Jon Mason <jdmason@...zu.us>, Daniel Drake <dsd@...too.org>,
        Ulrich Kunitz <kune@...ne-taler.de>,
        Kalle Valo <kvalo@...eaurora.org>,
        linux-wireless@...r.kernel.org, linux-usb@...r.kernel.org,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Arend van Spriel <arend.vanspriel@...adcom.com>,
        Franky Lin <franky.lin@...adcom.com>,
        Hante Meuleman <hante.meuleman@...adcom.com>,
        Chi-Hsien Lin <chi-hsien.lin@...ress.com>,
        Wright Feng <wright.feng@...ress.com>,
        brcm80211-dev-list.pdl@...adcom.com,
        brcm80211-dev-list@...ress.com,
        Stanislav Yakovlev <stas.yakovlev@...il.com>,
        Stanislaw Gruszka <stf_xl@...pl>,
        Johannes Berg <johannes.berg@...el.com>,
        Emmanuel Grumbach <emmanuel.grumbach@...el.com>,
        Luca Coelho <luciano.coelho@...el.com>,
        Intel Linux Wireless <linuxwifi@...el.com>,
        Jouni Malinen <j@...fi>,
        Amitkumar Karwar <amitkarwar@...il.com>,
        Ganapathi Bhat <ganapathi.bhat@....com>,
        Xinming Hu <huxinming820@...il.com>,
        libertas-dev@...ts.infradead.org,
        Pascal Terjan <pterjan@...gle.com>,
        Ping-Ke Shih <pkshih@...ltek.com>
Subject: [patch 17/35] net: sun3lance: Remove redundant checks in interrupt handler

From: Sebastian Andrzej Siewior <bigeasy@...utronix.de>

lance_interrupt() contains two pointless checks:

 - A check whether the 'dev_id' argument is NULL. 'dev_id' is the pointer
   which was handed in to request_irq() and the interrupt handler will
   always be invoked with that pointer as 'dev_id' argument by the core
   code.

 - A check for interrupt reentrancy. The core code already guarantees
   non-reentrancy of interrupt handlers.

Remove these check.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@...utronix.de>
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Cc: "David S. Miller" <davem@...emloft.net>
Cc: Jakub Kicinski <kuba@...nel.org>
Cc: netdev@...r.kernel.org
---
 drivers/net/ethernet/amd/sun3lance.c |   11 -----------
 1 file changed, 11 deletions(-)

--- a/drivers/net/ethernet/amd/sun3lance.c
+++ b/drivers/net/ethernet/amd/sun3lance.c
@@ -657,16 +657,6 @@ static irqreturn_t lance_interrupt( int
 	struct net_device *dev = dev_id;
 	struct lance_private *lp = netdev_priv(dev);
 	int csr0;
-	static int in_interrupt;
-
-	if (dev == NULL) {
-		DPRINTK( 1, ( "lance_interrupt(): invalid dev_id\n" ));
-		return IRQ_NONE;
-	}
-
-	if (in_interrupt)
-		DPRINTK( 2, ( "%s: Re-entering the interrupt handler.\n", dev->name ));
-	in_interrupt = 1;
 
  still_more:
 	flush_cache_all();
@@ -774,7 +764,6 @@ static irqreturn_t lance_interrupt( int
 
 	DPRINTK( 2, ( "%s: exiting interrupt, csr0=%#04x.\n",
 				  dev->name, DREG ));
-	in_interrupt = 0;
 	return IRQ_HANDLED;
 }