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From: Karl Beldan <karl.beldan@gmail.com>
To: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org,
	Karl Beldan <karl.beldan+oss@gmail.com>,
	stable@vger.kernel.org, Ralf Baechle <ralf@linux-mips.org>,
	Jonas Gorski <jogo@openwrt.org>
Subject: [RESEND PATCH] MIPS: head: Reorder instructions missing a delay slot
Date: Tue, 27 Jun 2017 19:22:16 +0000	[thread overview]
Message-ID: <20170627192216.29364-1-karl.beldan+oss@gmail.com> (raw)

In this sequence the 'move' is assumed in the delay slot of the 'beq',
but head.S is in reorder mode and the former gets pushed one 'nop'
farther by the assembler.

The corrected behavior made booting with an UHI supplied dtb erratic.

Fixes: 15f37e158892 ("MIPS: store the appended dtb address in a variable")
Cc: <stable@vger.kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Jonas Gorski <jogo@openwrt.org>
Signed-off-by: Karl Beldan <karl.beldan+oss@gmail.com>
---
 arch/mips/kernel/head.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/kernel/head.S b/arch/mips/kernel/head.S
index cf05220..d1bb506 100644
--- a/arch/mips/kernel/head.S
+++ b/arch/mips/kernel/head.S
@@ -106,8 +106,8 @@ NESTED(kernel_entry, 16, sp)			# kernel entry point
 	beq		t0, t1, dtb_found
 #endif
 	li		t1, -2
-	beq		a0, t1, dtb_found
 	move		t2, a1
+	beq		a0, t1, dtb_found
 
 	li		t2, 0
 dtb_found:
-- 
2.10.1

             reply	other threads:[~2017-06-27 19:22 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-06-27 19:22 Karl Beldan [this message]
2017-06-27 20:31 ` [RESEND PATCH] MIPS: head: Reorder instructions missing a delay slot James Hogan
2017-06-27 20:31   ` James Hogan
2017-06-27 21:40 ` Ralf Baechle

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