On Thu, Jan 06, 2022 at 04:18:01PM +0800, Takashi Iwai wrote: > Well, 32bit DMA mask practically never fails on x86 (and other > architectures, IIRC). It's fine to add a sanity check, but it's > better to be mentioned that it never fails. Actually, I have already found many place check the 32bit DMA mask. For example: snd_ad1889_create() in `sound/pci/ad1889.c`, snd_vortex_create() in `sound/pci/au88x0/au88x0.c` tegra_pcm_dma_allocate() in `sound/soc/tegra/tegra_pcm.c`. Therefore, I think there must be some reason that 32bit may fail. So, to make the system more robust, it should be better to add the sanity check. Sincerely thanks, Jiang
