This series is what all the work was about: support the "dual-/quad-pumped"
modes of the E-MU cards.
Oswald Buddenhagen (8):
ALSA: emu10k1: introduce alternative E-MU D.A.S. mode
ALSA: emu10k1: improve mixer control naming in E-MU D.A.S. mode
ALSA: emu10k1: set the "no filtering" bits on PCM voices
ALSA: emu10k1: make playback in E-MU D.A.S. mode 32-bit
ALSA: add snd_ctl_add_locked()
ALSA: emu10k1: add support for 2x/4x word clocks in E-MU D.A.S. mode
ALSA: emu10k1: add high-rate capture in E-MU D.A.S. mode
ALSA: emu10k1: add high-rate playback in E-MU D.A.S. mode
include/sound/control.h | 1 +
include/sound/emu10k1.h | 11 +
sound/core/control.c | 31 ++
sound/pci/emu10k1/emu10k1.c | 29 +-
sound/pci/emu10k1/emu10k1_main.c | 19 +-
sound/pci/emu10k1/emufx.c | 109 +++-
sound/pci/emu10k1/emumixer.c | 901 +++++++++++++++++++++++++++----
sound/pci/emu10k1/emupcm.c | 422 +++++++++++++--
sound/pci/emu10k1/emuproc.c | 5 +
sound/pci/emu10k1/io.c | 30 +-
sound/pci/emu10k1/voice.c | 6 +
11 files changed, 1383 insertions(+), 181 deletions(-)
Range-diff against v1:
1: c8c1fbba5e52 = 1: 7cb49147164f ALSA: emu10k1: introduce alternative E-MU D.A.S. mode
2: 879066428bee = 2: aa9ead00e045 ALSA: emu10k1: improve mixer control naming in E-MU D.A.S. mode
3: b663229a0f46 = 3: ac830e67322f ALSA: emu10k1: set the "no filtering" bits on PCM voices
4: a9de9a73571e = 4: 26e0b7c02c1d ALSA: emu10k1: make playback in E-MU D.A.S. mode 32-bit
5: 0f1950b03193 ! 5: 94b64e6c123d ALSA: add snd_ctl_add_locked()
@@ Commit message
This is in fact more symmetrical to snd_ctl_remove() than snd_ctl_add()
is - the former could be named snd_ctl_remove_locked() just as well.
+ One may argue that this is going in the wrong direction, as drivers have
+ no business managing the lock. This may be true in principle, but in
+ practice the vast majority of controls is created even before the device
+ was registered, and therefore before any locking is necessary at all.
+ That means that an even more radical approach of changing snd_ctl_add()
+ do do no locking, and converting the call sites that actually need
+ locking to a new function, would better match reality, and would be
+ somewhat more efficient at that. However, that seems a bit risky and way
+ too much work.
+
This will be used to dynamically change the available controls from
another control's put() callback, which is already locked.
One might want to add snd_ctl_replace_locked() for completeness, but I
have no use for it now.
Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@xxxxxx>
+ ---
+ v2:
+ - extended commit message
## include/sound/control.h ##
@@ include/sound/control.h: void snd_ctl_notify_one(struct snd_card * card, unsigned int mask, struct snd_kc
6: 511efe4ac7ad ! 6: 7bc314bae7f2 ALSA: emu10k1: add support for 2x/4x word clocks in E-MU D.A.S. mode
@@ Commit message
on playback, and throw away the excess ones on capture. Input-to-output
monitoring does actually use the full sample rate, though.
- Notably, add_ctls() now uses snd_ctl_add_locked(), so it doesn't
- deadlock when called from snd_emu1010_clock_shift_put(). This also
- affects the initial creation of the controls, which is OK, as that is
- done before the card is registered, so no concurrent access can occur.
+ Due to hardware constraints, changing the clock multiplier (CM) changes
+ the available audio ports and the number of available channels. This has
+ an impact on the channel routing mixer controls. One way to deal with
+ this would be presenting a union of all possibilities, and simply
+ ignoring currently inapplicable settings. However, this would be a
+ terrible user experience, and go against the spirit of prior patches
+ aimed at decluttering the mixer. Therefore, we do dynamic
+ reconfiguration (DR) of the mixer in response to changing the CM.
+
+ DR is somewhat controversial, as it has the potential to crash poorly
+ programmed applications. But that in itself isn't a very convincing
+ argument against it, as by that logic we'd have to ban all hot-plugging.
+ Such crashes would also not really qualify as regressions, as the D.A.S.
+ mode is a new opt-in feature, and therefore no previously stable setups
+ would be impacted. Also, pendantically, the driver already had DR via
+ SNDRV_EMU10K1_IOCTL_CODE_POKE. A somewhat valid concern is that changing
+ mixer settings is a non-privileged operation and therefore potential
+ crashes could be exploited for a somewhat more impactful nuisance attack
+ on another user than messing with the mixer per se. However, systemd &
+ co. limit device access to the user currently logged in on the seat
+ owning the device.
+
+ There is a specific concern about doing DR in response to changing a
+ mixer control's value, as an application may legitimately react to DR by
+ updating all mixer settings in turn. However, that update should write
+ the same value to the clock multiplier, thus terminating the recursion.
+
+ One may limit DR to merely disabling inapplicable controls, in the hope
+ that this would be better handled than completely tearing down and
+ re-creating controls as we do. However, there is no guarantee for that.
+ And because it is impossible to disable particular enum values within a
+ control, it would be necessary to have three complete sets of
+ per-channel controls. This would yield an extremely cluttered and
+ confusing UI if the application (reasonably) chose to merely visually
+ disable inactive controls rather than hiding them.
+
+ We do the DR synchronously from within snd_emu1010_clock_shift_put().
+ This was enabled by commit 5bbb1ab5bd ("control: use counting semaphore
+ as write lock for ELEM_WRITE operation"); we merely need to make
+ add_ctls() use snd_ctl_add_locked() instead of snd_ctl_add(), so it
+ doesn't deadlock. That also affects the initial creation of the
+ controls, which is OK, as that is done before the card is registered, so
+ no concurrent access can occur.
+
+ It would be possible to do the DR in a tasklet after the ioctl finishes.
+ However, it is not obvious what actual problem that would solve, and the
+ added asynchronicity would significantly complicate matters, esp. wrt.
+ the batch updates expected during mixer state restoration.
Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@xxxxxx>
+ ---
+ v2:
+ - expanded commit message
## include/sound/emu10k1.h ##
@@ include/sound/emu10k1.h: struct snd_emu1010 {
7: d5cb50ca707f = 7: 72a156fb32cd ALSA: emu10k1: add high-rate capture in E-MU D.A.S. mode
8: 319425a4ccb6 ! 8: 6d35891832b3 ALSA: emu10k1: add high-rate playback in E-MU D.A.S. mode
@@ Commit message
d948035a92 ("Remove PCM xfer_align sw params").
Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@xxxxxx>
+ ---
+ v2:
+ - fixed `sparse` warning re missing __user annotation
## sound/pci/emu10k1/emufx.c ##
@@ sound/pci/emu10k1/emufx.c: static int _snd_emu10k1_das_init_efx(struct snd_emu10k1 *emu)
@@ sound/pci/emu10k1/emupcm.c: static int snd_emu10k1_efx_playback_trigger(struct s
+ for (i = 0; i < channels; i++) {
+ for (j = 0; j < subchans; j++) {
+ u32 *dst = get_dma_ptr_x(runtime, shift, i, j, hwoff);
-+ u32 *src = (u32 *)buf + j * channels + i;
++ u32 __user *src = (u32 __user *)buf + j * channels + i;
+ for (k = 0; k < frames; k++, dst++, src += voices)
+ unsafe_get_user(*dst, src, faulted);
+ }
--
2.40.0.152.g15d061e6df
