Commit 0d1d365d authored Nov 25, 2016 by Paul Burton Committed by Greg Kroah-Hartman Sep 19, 2018

MIPS: WARN_ON invalid DMA cache maintenance, not BUG_ON



[ Upstream commit d4da0e97baea8768b3d66ccef3967bebd50dfc3b ]

If a driver causes DMA cache maintenance with a zero length then we
currently BUG and kill the kernel. As this is a scenario that we may
well be able to recover from, WARN & return in the condition instead.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/14623/


Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 1181e868

arch/mips/mm/c-r4k.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -835,7 +835,8 @@ static void r4k_flush_icache_user_range(unsigned long start, unsigned long end)
		static void r4k_dma_cache_wback_inv(unsigned long addr, unsigned long size)
		{
		/* Catch bad driver code */
		BUG_ON(size == 0);
		if (WARN_ON(size == 0))
		return;

		preempt_disable();
		if (cpu_has_inclusive_pcaches) {
		@@ -871,7 +872,8 @@ static void r4k_dma_cache_wback_inv(unsigned long addr, unsigned long size)
		static void r4k_dma_cache_inv(unsigned long addr, unsigned long size)
		{
		/* Catch bad driver code */
		BUG_ON(size == 0);
		if (WARN_ON(size == 0))
		return;

		preempt_disable();
		if (cpu_has_inclusive_pcaches) {