[PATCH 15/15] MIPS: smp-cps: Stop printing EJTAG exceptions to UART

From	Paul Burton <paul.burton@imgtec.com>
Newsgroups	linux.kernel
Subject	[PATCH 15/15] MIPS: smp-cps: Stop printing EJTAG exceptions to UART
Date	2016-02-03 04:30 +0100
Message-ID	<qXWiK-4Pu-7@gated-at.bofh.it> (permalink)
References	<qXW93-4Ls-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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When CONFIG_MIPS_CPS_NS16550 is enabled, some register state is dumped
to the UART when an exception is taken via the BEV on secondary cores.
EJTAG exceptions are architecturally expected to be handled by the BEV
even when Status.BEV is 0. This effectively means that if userland
executes an sdbbp instruction on a secondary core then the kernel dumps
register state to the UART even though the exception is perfectly normal
& expected. Prevent this by simply not dumping information to the UART
for EJTAG exceptions.

Fixes: 609cf6f2291a ("MIPS: CPS: Early debug using an ns16550-compatible UART")
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
---

 arch/mips/kernel/cps-vec.S | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/mips/kernel/cps-vec.S b/arch/mips/kernel/cps-vec.S
index c28138d..51b98dc 100644
--- a/arch/mips/kernel/cps-vec.S
+++ b/arch/mips/kernel/cps-vec.S
@@ -223,7 +223,6 @@ LEAF(excep_intex)
 
 .org 0x480
 LEAF(excep_ejtag)
-	DUMP_EXCEP("EJTAG")
 	PTR_LA	k0, ejtag_debug_handler
 	jr	k0
 	 nop
-- 
2.7.0

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[PATCH 00/15] Support for MIPSr6 Virtual Processors (multi-threading) Paul Burton <paul.burton@imgtec.com> - 2016-02-03 04:20 +0100
  [PATCH 08/15] irqchip: mips-gic: Provide VP ID accessor Paul Burton <paul.burton@imgtec.com> - 2016-02-03 04:20 +0100
  [PATCH 06/15] MIPS: CM: Fix mips_cm_max_vp_width for UP kernels Paul Burton <paul.burton@imgtec.com> - 2016-02-03 04:20 +0100
    Re: [PATCH 06/15] MIPS: CM: Fix mips_cm_max_vp_width for UP kernels James Hogan <james.hogan@imgtec.com> - 2016-02-03 16:00 +0100
      Re: [PATCH 06/15] MIPS: CM: Fix mips_cm_max_vp_width for UP kernels Paul Burton <paul.burton@imgtec.com> - 2016-02-03 16:50 +0100
        Re: [PATCH 06/15] MIPS: CM: Fix mips_cm_max_vp_width for UP kernels James Hogan <james.hogan@imgtec.com> - 2016-02-03 17:20 +0100
  [PATCH 15/15] MIPS: smp-cps: Stop printing EJTAG exceptions to UART Paul Burton <paul.burton@imgtec.com> - 2016-02-03 04:30 +0100

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