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ALSA: hda: Apply aligned MMIO access only conditionally
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It turned out that the recent simplification of HD-audio bus access
helpers caused a regression on the virtual HD-audio device on QEMU
with ARM platforms.  The driver got a CORB/RIRB timeout and couldn't
probe any codecs.

The essential difference that caused a problem was the enforced
aligned MMIO accesses by simplification.  Since snd-hda-tegra driver
is enabled on ARM, it enables CONFIG_SND_HDA_ALIGNED_MMIO, which makes
the all HD-audio drivers using the aligned MMIO accesses.  While this
is mandatory for snd-hda-tegra, it seems that snd-hda-intel on ARM
gets broken by this access pattern.

For addressing the regression, this patch introduces a new flag,
aligned_mmio, to hdac_bus object, and applies the aligned MMIO only
when this flag is set.  This change affects only platforms with
CONFIG_SND_HDA_ALIGNED_MMIO set, i.e. mostly only for ARM platforms.

Unfortunately the patch became a big bigger than it should be, just
because the former calls didn't take hdac_bus object in the argument,
hence we had to extend the call patterns.

Fixes: 19abfef ("ALSA: hda: Direct MMIO accesses")
BugLink: https://bugzilla.opensuse.org/show_bug.cgi?id=1161152
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200120104127.28985-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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Takashi Iwai committed Jan 20, 2020
1 parent e5dbdcb commit 4d024fe
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Showing 2 changed files with 54 additions and 24 deletions.
77 changes: 53 additions & 24 deletions include/sound/hdaudio.h
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Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,7 @@

#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/pm_runtime.h>
#include <linux/timecounter.h>
#include <sound/core.h>
Expand Down Expand Up @@ -330,6 +331,7 @@ struct hdac_bus {
bool chip_init:1; /* h/w initialized */

/* behavior flags */
bool aligned_mmio:1; /* aligned MMIO access */
bool sync_write:1; /* sync after verb write */
bool use_posbuf:1; /* use position buffer */
bool snoop:1; /* enable snooping */
Expand Down Expand Up @@ -405,34 +407,61 @@ void snd_hdac_bus_free_stream_pages(struct hdac_bus *bus);
unsigned int snd_hdac_aligned_read(void __iomem *addr, unsigned int mask);
void snd_hdac_aligned_write(unsigned int val, void __iomem *addr,
unsigned int mask);
#define snd_hdac_reg_writeb(v, addr) snd_hdac_aligned_write(v, addr, 0xff)
#define snd_hdac_reg_writew(v, addr) snd_hdac_aligned_write(v, addr, 0xffff)
#define snd_hdac_reg_readb(addr) snd_hdac_aligned_read(addr, 0xff)
#define snd_hdac_reg_readw(addr) snd_hdac_aligned_read(addr, 0xffff)
#else /* CONFIG_SND_HDA_ALIGNED_MMIO */
#define snd_hdac_reg_writeb(val, addr) writeb(val, addr)
#define snd_hdac_reg_writew(val, addr) writew(val, addr)
#define snd_hdac_reg_readb(addr) readb(addr)
#define snd_hdac_reg_readw(addr) readw(addr)
#endif /* CONFIG_SND_HDA_ALIGNED_MMIO */
#define snd_hdac_reg_writel(val, addr) writel(val, addr)
#define snd_hdac_reg_readl(addr) readl(addr)
#define snd_hdac_aligned_mmio(bus) (bus)->aligned_mmio
#else
#define snd_hdac_aligned_mmio(bus) false
#define snd_hdac_aligned_read(addr, mask) 0
#define snd_hdac_aligned_write(val, addr, mask) do {} while (0)
#endif

static inline void snd_hdac_reg_writeb(struct hdac_bus *bus, void __iomem *addr,
u8 val)
{
if (snd_hdac_aligned_mmio(bus))
snd_hdac_aligned_write(val, addr, 0xff);
else
writeb(val, addr);
}

static inline void snd_hdac_reg_writew(struct hdac_bus *bus, void __iomem *addr,
u16 val)
{
if (snd_hdac_aligned_mmio(bus))
snd_hdac_aligned_write(val, addr, 0xffff);
else
writew(val, addr);
}

static inline u8 snd_hdac_reg_readb(struct hdac_bus *bus, void __iomem *addr)
{
return snd_hdac_aligned_mmio(bus) ?
snd_hdac_aligned_read(addr, 0xff) : readb(addr);
}

static inline u16 snd_hdac_reg_readw(struct hdac_bus *bus, void __iomem *addr)
{
return snd_hdac_aligned_mmio(bus) ?
snd_hdac_aligned_read(addr, 0xffff) : readw(addr);
}

#define snd_hdac_reg_writel(bus, addr, val) writel(val, addr)
#define snd_hdac_reg_readl(bus, addr) readl(addr)

/*
* macros for easy use
*/
#define _snd_hdac_chip_writeb(chip, reg, value) \
snd_hdac_reg_writeb(value, (chip)->remap_addr + (reg))
snd_hdac_reg_writeb(chip, (chip)->remap_addr + (reg), value)
#define _snd_hdac_chip_readb(chip, reg) \
snd_hdac_reg_readb((chip)->remap_addr + (reg))
snd_hdac_reg_readb(chip, (chip)->remap_addr + (reg))
#define _snd_hdac_chip_writew(chip, reg, value) \
snd_hdac_reg_writew(value, (chip)->remap_addr + (reg))
snd_hdac_reg_writew(chip, (chip)->remap_addr + (reg), value)
#define _snd_hdac_chip_readw(chip, reg) \
snd_hdac_reg_readw((chip)->remap_addr + (reg))
snd_hdac_reg_readw(chip, (chip)->remap_addr + (reg))
#define _snd_hdac_chip_writel(chip, reg, value) \
snd_hdac_reg_writel(value, (chip)->remap_addr + (reg))
snd_hdac_reg_writel(chip, (chip)->remap_addr + (reg), value)
#define _snd_hdac_chip_readl(chip, reg) \
snd_hdac_reg_readl((chip)->remap_addr + (reg))
snd_hdac_reg_readl(chip, (chip)->remap_addr + (reg))

/* read/write a register, pass without AZX_REG_ prefix */
#define snd_hdac_chip_writel(chip, reg, value) \
Expand Down Expand Up @@ -540,17 +569,17 @@ int snd_hdac_get_stream_stripe_ctl(struct hdac_bus *bus,
*/
/* read/write a register, pass without AZX_REG_ prefix */
#define snd_hdac_stream_writel(dev, reg, value) \
snd_hdac_reg_writel(value, (dev)->sd_addr + AZX_REG_ ## reg)
snd_hdac_reg_writel((dev)->bus, (dev)->sd_addr + AZX_REG_ ## reg, value)
#define snd_hdac_stream_writew(dev, reg, value) \
snd_hdac_reg_writew(value, (dev)->sd_addr + AZX_REG_ ## reg)
snd_hdac_reg_writew((dev)->bus, (dev)->sd_addr + AZX_REG_ ## reg, value)
#define snd_hdac_stream_writeb(dev, reg, value) \
snd_hdac_reg_writeb(value, (dev)->sd_addr + AZX_REG_ ## reg)
snd_hdac_reg_writeb((dev)->bus, (dev)->sd_addr + AZX_REG_ ## reg, value)
#define snd_hdac_stream_readl(dev, reg) \
snd_hdac_reg_readl((dev)->sd_addr + AZX_REG_ ## reg)
snd_hdac_reg_readl((dev)->bus, (dev)->sd_addr + AZX_REG_ ## reg)
#define snd_hdac_stream_readw(dev, reg) \
snd_hdac_reg_readw((dev)->sd_addr + AZX_REG_ ## reg)
snd_hdac_reg_readw((dev)->bus, (dev)->sd_addr + AZX_REG_ ## reg)
#define snd_hdac_stream_readb(dev, reg) \
snd_hdac_reg_readb((dev)->sd_addr + AZX_REG_ ## reg)
snd_hdac_reg_readb((dev)->bus, (dev)->sd_addr + AZX_REG_ ## reg)

/* update a register, pass without AZX_REG_ prefix */
#define snd_hdac_stream_updatel(dev, reg, mask, val) \
Expand Down
1 change: 1 addition & 0 deletions sound/pci/hda/hda_tegra.c
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Original file line number Diff line number Diff line change
Expand Up @@ -398,6 +398,7 @@ static int hda_tegra_create(struct snd_card *card,
return err;

chip->bus.needs_damn_long_delay = 1;
chip->bus.core.aligned_mmio = 1;

err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops);
if (err < 0) {
Expand Down

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