4.9-stable review patch. If anyone has any objections, please let me know.
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From: Takashi Iwai tiwai@suse.de
commit 20a1ea2222e7cbf96e9bf8579362e971491e6aea upstream.
I got the following kernel warning when loading snd-soc-skl module on Dell Latitude 7270 laptop: memremap attempted on mixed range 0x0000000000000000 size: 0x0 WARNING: CPU: 0 PID: 484 at kernel/memremap.c:98 memremap+0x8a/0x180 Call Trace: skl_nhlt_init+0x82/0xf0 [snd_soc_skl] skl_probe+0x2ee/0x7c0 [snd_soc_skl] ....
It seems that the machine doesn't support the SKL DSP gives the empty NHLT entry, and it triggers the warning. For avoiding it, let do the zero check before calling memremap().
Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- sound/soc/intel/skylake/skl-nhlt.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/sound/soc/intel/skylake/skl-nhlt.c +++ b/sound/soc/intel/skylake/skl-nhlt.c @@ -41,7 +41,8 @@ struct nhlt_acpi_table *skl_nhlt_init(st obj = acpi_evaluate_dsm(handle, OSC_UUID, 1, 1, NULL); if (obj && obj->type == ACPI_TYPE_BUFFER) { nhlt_ptr = (struct nhlt_resource_desc *)obj->buffer.pointer; - nhlt_table = (struct nhlt_acpi_table *) + if (nhlt_ptr->length) + nhlt_table = (struct nhlt_acpi_table *) memremap(nhlt_ptr->min_addr, nhlt_ptr->length, MEMREMAP_WB); ACPI_FREE(obj);