The dsp_registers field of struct echoaduio has the volatile modifier, but it's basically superfluous; the field is accessed only for the base pointer of readl() and writel(), hence marking with __iomem alone should suffice. OTOH, having the volatile prefix causes a compile warning like: sound/pci/echoaudio/echoaudio.c:1878:14: warning: passing argument 1 of 'iounmap' discards 'volatile' qualifier from pointer target type [-Wdiscarded-qualifiers] So it's better to drop this superfluous modifier. Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> --- sound/pci/echoaudio/echoaudio.c | 3 +-- sound/pci/echoaudio/echoaudio.h | 2 +- 2 files changed, 2 insertions(+), 3 deletions(-) diff --git a/sound/pci/echoaudio/echoaudio.c b/sound/pci/echoaudio/echoaudio.c index 6aeb99aa2414..1b7a67ccabce 100644 --- a/sound/pci/echoaudio/echoaudio.c +++ b/sound/pci/echoaudio/echoaudio.c @@ -1950,8 +1950,7 @@ static int snd_echo_create(struct snd_card *card, snd_echo_free(chip); return -EBUSY; } - chip->dsp_registers = (volatile u32 __iomem *) - ioremap(chip->dsp_registers_phys, sz); + chip->dsp_registers = ioremap(chip->dsp_registers_phys, sz); if (!chip->dsp_registers) { dev_err(chip->card->dev, "ioremap failed\n"); snd_echo_free(chip); diff --git a/sound/pci/echoaudio/echoaudio.h b/sound/pci/echoaudio/echoaudio.h index 30c640931f1e..0afe13f7b6e5 100644 --- a/sound/pci/echoaudio/echoaudio.h +++ b/sound/pci/echoaudio/echoaudio.h @@ -419,7 +419,7 @@ struct echoaudio { short asic_code; /* Current ASIC code */ u32 comm_page_phys; /* Physical address of the * memory seen by DSP */ - volatile u32 __iomem *dsp_registers; /* DSP's register base */ + u32 __iomem *dsp_registers; /* DSP's register base */ u32 active_mask; /* Chs. active mask or * punks out */ #ifdef CONFIG_PM_SLEEP -- 2.16.4