So back when the i915 power well support landed in
commit 99a2008d0b32d72dfc2a54e7be1eb698dd2e3bd6
Author: Wang Xingchao <xingchao.wang@xxxxxxxxxxxxxxx>
Date: Thu May 30 22:07:10 2013 +0800
ALSA: hda - Add power-welll support for haswell HDA
the logic to handle the cross-module depencies was hand-rolled using a
async work item, and that just doesn't work.
The correct way to handle cross-module deps is either:
- request_module + failing when the other module isn't there
OR
- failing the module load with EPROBE_DEFER.
You can't mix them, if you do then the entire load path just
busy-spins blowing through cpu cycles forever with no way to stop
this.
snd-hda-intel does mix it, because the hda codec drivers are loaded
using request_module, but the i915 depency is handled using
PROBE_DEFER (or well, should be, but I haven't found any code at all).
This is a major pain when trying to debug i915 load failures.
This patch here is a horrible hackish attempt at somewhat correctly
wriing EPROBE_DEFER through. Stuff that's missing:
- Check all the other places where load errors are conveniently
dropped on the floor.
- Also fix up the firmware_cb path.
- Drop the debug noise I've left in to make it clear this isn't
anything for merging.
Cheers, Daniel
Cc: Jaroslav Kysela <perex@xxxxxxxx>
Cc: Takashi Iwai <tiwai@xxxxxxxx>
Cc: "GitAuthor: Daniel Vetter" <daniel.vetter@xxxxxxxx>
Cc: Guneshwor Singh <guneshwor.o.singh@xxxxxxxxx>
Cc: Hardik T Shah <hardik.t.shah@xxxxxxxxx>
Cc: Julia Lawall <Julia.Lawall@xxxxxxx>
Cc: Vinod Koul <vinod.koul@xxxxxxxxx>
Cc: "Subhransu S. Prusty" <subhransu.s.prusty@xxxxxxxxx>
Cc: Libin Yang <libin.yang@xxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
drivers/base/dd.c | 2 ++
sound/pci/hda/hda_bind.c | 6 +++---
sound/pci/hda/hda_controller.c | 8 +++++++-
sound/pci/hda/hda_intel.c | 13 +++++++++----
4 files changed, 21 insertions(+), 8 deletions(-)
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 4882f06d12df..842bc8782124 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -17,6 +17,8 @@
* This file is released under the GPLv2
*/
+#define DEBUG
+
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
diff --git a/sound/pci/hda/hda_bind.c b/sound/pci/hda/hda_bind.c
index 6efadbfb3fe3..0bc164a17493 100644
--- a/sound/pci/hda/hda_bind.c
+++ b/sound/pci/hda/hda_bind.c
@@ -253,7 +253,7 @@ static int codec_bind_generic(struct hda_codec *codec)
request_codec_module(codec);
if (codec_probed(codec))
return 0;
- return -ENODEV;
+ return -EPROBE_DEFER;
}
#if IS_ENABLED(CONFIG_SND_HDA_GENERIC)
@@ -289,8 +289,8 @@ int snd_hda_codec_configure(struct hda_codec *codec)
codec_bind_module(codec);
if (!codec->preset) {
err = codec_bind_generic(codec);
- if (err < 0) {
- codec_err(codec, "Unable to bind the codec\n");
+ if (WARN_ON(err < 0)) {
+ codec_err(codec, "Unable to bind the codec, err=%i\n", err);
goto error;
}
}
diff --git a/sound/pci/hda/hda_controller.c b/sound/pci/hda/hda_controller.c
index 3715a5725613..4b4262c72327 100644
--- a/sound/pci/hda/hda_controller.c
+++ b/sound/pci/hda/hda_controller.c
@@ -1337,9 +1337,15 @@ EXPORT_SYMBOL_GPL(azx_probe_codecs);
/* configure each codec instance */
int azx_codec_configure(struct azx *chip)
{
+ int ret;
+
struct hda_codec *codec;
list_for_each_codec(codec, &chip->bus) {
- snd_hda_codec_configure(codec);
+ ret = snd_hda_codec_configure(codec);
+ if (ret) {
+ printk("bailing real hard %i\n", ret);
+ return ret;
+ }
}
return 0;
}
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index 07ea7f48aa01..8241387cc8ca 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -1649,7 +1649,8 @@ static void azx_check_snoop_available(struct azx *chip)
static void azx_probe_work(struct work_struct *work)
{
struct hda_intel *hda = container_of(work, struct hda_intel, probe_work);
- azx_probe_continue(&hda->chip);
+
+ WARN_ON(1);
}
static int default_bdl_pos_adj(struct azx *chip)
@@ -2158,7 +2159,6 @@ static int azx_probe(struct pci_dev *pci,
azx_firmware_cb);
if (err < 0)
goto out_free;
- schedule_probe = false; /* continued in azx_firmware_cb() */
}
#endif /* CONFIG_SND_HDA_PATCH_LOADER */
@@ -2167,8 +2167,13 @@ static int azx_probe(struct pci_dev *pci,
dev_err(card->dev, "Haswell/Broadwell HDMI/DP must build in CONFIG_SND_HDA_I915\n");
#endif
- if (schedule_probe)
- schedule_work(&hda->probe_work);
+ if (schedule_probe) {
+ err = azx_probe_continue(chip);
+ if (err) {
+ printk("hit the right error return finally! err=%i\n", err);
+ goto out_free;
+ }
+ }
dev++;
if (chip->disabled)
--
2.5.5
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