This is a note to let you know that I've just added the patch titled

ALSA: pcm: Use dma_bytes as size parameter in dma_mmap_coherent()

to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: alsa-pcm-use-dma_bytes-as-size-parameter-in-dma_mmap_coherent.patch and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From 9066ae7ff5d89c0b5daa271e2d573540097a94fa Mon Sep 17 00:00:00 2001

From: Stefan Roese sr@denx.de Date: Mon, 26 Mar 2018 16:10:21 +0200 Subject: ALSA: pcm: Use dma_bytes as size parameter in dma_mmap_coherent()

From: Stefan Roese sr@denx.de

commit 9066ae7ff5d89c0b5daa271e2d573540097a94fa upstream.

When trying to use the driver (e.g. aplay *.wav), the 4MiB DMA buffer will get mmapp'ed in 16KiB chunks. But this fails with the 2nd 16KiB area, as the page offset is outside of the VMA range (size), which is currently used as size parameter in snd_pcm_lib_default_mmap(). By using the DMA buffer size (dma_bytes) instead, the complete DMA buffer can be mmapp'ed and the issue is fixed.

This issue was detected on an ARM platform (TI AM57xx) using the RME HDSP MADI PCIe soundcard.

Fixes: 657b1989dacf ("ALSA: pcm - Use dma_mmap_coherent() if available") Signed-off-by: Stefan Roese sr@denx.de Cc: stable@vger.kernel.org Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- sound/core/pcm_native.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -3422,7 +3422,7 @@ int snd_pcm_lib_default_mmap(struct snd_ area, substream->runtime->dma_area, substream->runtime->dma_addr, - area->vm_end - area->vm_start); + substream->runtime->dma_bytes); #endif /* CONFIG_X86 */ /* mmap with fault handler */ area->vm_ops = &snd_pcm_vm_ops_data_fault;

Patches currently in stable-queue which might be from sr@denx.de are

queue-4.15/alsa-pcm-use-dma_bytes-as-size-parameter-in-dma_mmap_coherent.patch