linux-kernel - [PATCH 4.4 25/56] MIPS: netlogic: xlr: Remove erroneous check in nlm_fmn

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Date:   Fri, 20 Sep 2019 00:04:06 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Paul Burton <paul.burton@...s.com>,
        Ganesan Ramalingam <ganesanr@...adcom.com>,
        James Hogan <jhogan@...nel.org>,
        Jayachandran C <jnair@...iumnetworks.com>,
        John Crispin <john@...ozen.org>,
        Ralf Baechle <ralf@...ux-mips.org>, linux-mips@...ux-mips.org,
        Guenter Roeck <linux@...ck-us.net>
Subject: [PATCH 4.4 25/56] MIPS: netlogic: xlr: Remove erroneous check in nlm_fmn_send()

From: Paul Burton <paul.burton@...s.com>

commit 02eec6c9fc0cb13169cc97a6139771768791f92b upstream.

In nlm_fmn_send() we have a loop which attempts to send a message
multiple times in order to handle the transient failure condition of a
lack of available credit. When examining the status register to detect
the failure we check for a condition that can never be true, which falls
foul of gcc 8's -Wtautological-compare:

  In file included from arch/mips/netlogic/common/irq.c:65:
  ./arch/mips/include/asm/netlogic/xlr/fmn.h: In function 'nlm_fmn_send':
  ./arch/mips/include/asm/netlogic/xlr/fmn.h:304:22: error: bitwise
    comparison always evaluates to false [-Werror=tautological-compare]
     if ((status & 0x2) == 1)
                        ^~

If the path taken if this condition were true all we do is print a
message to the kernel console. Since failures seem somewhat expected
here (making the console message questionable anyway) and the condition
has clearly never evaluated true we simply remove it, rather than
attempting to fix it to check status correctly.

Signed-off-by: Paul Burton <paul.burton@...s.com>
Patchwork: https://patchwork.linux-mips.org/patch/20174/
Cc: Ganesan Ramalingam <ganesanr@...adcom.com>
Cc: James Hogan <jhogan@...nel.org>
Cc: Jayachandran C <jnair@...iumnetworks.com>
Cc: John Crispin <john@...ozen.org>
Cc: Ralf Baechle <ralf@...ux-mips.org>
Cc: linux-mips@...ux-mips.org
Cc: Guenter Roeck <linux@...ck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 arch/mips/include/asm/netlogic/xlr/fmn.h |    2 --
 1 file changed, 2 deletions(-)

--- a/arch/mips/include/asm/netlogic/xlr/fmn.h
+++ b/arch/mips/include/asm/netlogic/xlr/fmn.h
@@ -301,8 +301,6 @@ static inline int nlm_fmn_send(unsigned
 	for (i = 0; i < 8; i++) {
 		nlm_msgsnd(dest);
 		status = nlm_read_c2_status0();
-		if ((status & 0x2) == 1)
-			pr_info("Send pending fail!\n");
 		if ((status & 0x4) == 0)
 			return 0;
 	}