MIPS: WARN_ON invalid DMA cache maintenance, not BUG_ON (d4da0e97) · Commits · 戴 / test

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

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) {

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