Re: [PATCH 2/2 v2] ALSA: hda - Deferred probing with request_firmware_nowait()

[Takashi Iwai]

At Thu, 09 Aug 2012 15:54:04 +0200,
David Henningsson wrote:
> 
> On 08/09/2012 03:36 PM, Takashi Iwai wrote:
> > +/* callback from request_firmware_nowait() */
> > +static void azx_firmware_cb(const struct firmware *fw, void *context)
> > +{
> > +   struct snd_card *card = context;
> > +   struct azx *chip = card->private_data;
> > +   struct pci_dev *pci = chip->pci;
> > +
> > +   if (!fw) {
> > +   snd_printk(KERN_ERR SFX "Cannot load firmware, aborting\n");
> > +   goto error;
> > +   }
> 
> Another thing, aren't you missing a
> 
> chip->fw = fw;
> 
> here?

Ah, yes.


> > +
> > +   if (!chip->disabled) {
> > +   /* continue probing */
> > +   if (azx_probe_continue(chip))
> > +   goto error;
> > +   }
> > +   return; /* OK */
> > +
> > + error:
> > +   snd_card_free(card);
> > +   pci_set_drvdata(pci, NULL);
> > +}
> > +
> >   static int __devinit azx_probe(struct pci_dev *pci,
> >const struct pci_device_id *pci_id)
> >   {
> > static int dev;
> > struct snd_card *card;
> > struct azx *chip;
> > +   bool probe_deferred;
> > int err;
> >
> > if (dev >= SNDRV_CARDS)
> > @@ -3182,18 +3211,22 @@ static int __devinit azx_probe(struct pci_dev *pci,
> > if (err < 0)
> > goto out_free;
> > card->private_data = chip;
> 
> Right, this patch has the race removed, as the variable is no longer set 
> in azx_firmware_cb. To be picky, it's slightly confusing that 
> probe_deferred is also used for signalling a disabled chip. Maybe 
> "probe_now" (inverted) would have been even better, like this:

Yeah, this looks slightly more straightforward.

I'm going to send a revised version shortly.


thanks,

Takashi
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Re: [PATCH 2/2 v2] ALSA: hda - Deferred probing with request_firmware_nowait()

[Thierry Reding]

On Thu, Aug 09, 2012 at 03:54:04PM +0200, David Henningsson wrote:
> On 08/09/2012 03:36 PM, Takashi Iwai wrote:
> >+/* callback from request_firmware_nowait() */
> >+static void azx_firmware_cb(const struct firmware *fw, void *context)
> >+{
> >+struct snd_card *card = context;
> >+struct azx *chip = card->private_data;
> >+struct pci_dev *pci = chip->pci;
> >+
> >+if (!fw) {
> >+snd_printk(KERN_ERR SFX "Cannot load firmware, aborting\n");
> >+goto error;
> >+}
> 
> Another thing, aren't you missing a
> 
> chip->fw = fw;
> 
> here?

Adding that line here fixes the problem for me.

Thierry


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Re: [PATCH 2/2 v2] ALSA: hda - Deferred probing with request_firmware_nowait()

[David Henningsson]

On 08/09/2012 03:36 PM, Takashi Iwai wrote:

+/* callback from request_firmware_nowait() */
+static void azx_firmware_cb(const struct firmware *fw, void *context)
+{
+   struct snd_card *card = context;
+   struct azx *chip = card->private_data;
+   struct pci_dev *pci = chip->pci;
+
+   if (!fw) {
+   snd_printk(KERN_ERR SFX "Cannot load firmware, aborting\n");
+   goto error;
+   }


Another thing, aren't you missing a

chip->fw = fw;

here?


+
+   if (!chip->disabled) {
+   /* continue probing */
+   if (azx_probe_continue(chip))
+   goto error;
+   }
+   return; /* OK */
+
+ error:
+   snd_card_free(card);
+   pci_set_drvdata(pci, NULL);
+}
+
  static int __devinit azx_probe(struct pci_dev *pci,
   const struct pci_device_id *pci_id)
  {
static int dev;
struct snd_card *card;
struct azx *chip;
+   bool probe_deferred;
int err;

if (dev >= SNDRV_CARDS)
@@ -3182,18 +3211,22 @@ static int __devinit azx_probe(struct pci_dev *pci,
if (err < 0)
goto out_free;
card->private_data = chip;


Right, this patch has the race removed, as the variable is no longer set 
in azx_firmware_cb. To be picky, it's slightly confusing that 
probe_deferred is also used for signalling a disabled chip. Maybe 
"probe_now" (inverted) would have been even better, like this:



+   probe_deferred = chip->disabled;


probe_now = !chip->disabled;



  #ifdef CONFIG_SND_HDA_PATCH_LOADER
if (patch[dev] && *patch[dev]) {


(maybe we should not ask for firmware for a disabled chip either)


snd_printk(KERN_ERR SFX "Applying patch firmware '%s'\n",
   patch[dev]);
-   err = request_firmware(>fw, patch[dev], >dev);
+   err = request_firmware_nowait(THIS_MODULE, true, patch[dev],
+ >dev, GFP_KERNEL, card,
+ azx_firmware_cb);
if (err < 0)
goto out_free;
+   probe_deferred = true;


probe_now = false;


}
  #endif /* CONFIG_SND_HDA_PATCH_LOADER */

-   if (!chip->disabled) {
+   if (!probe_deferred) {


if (probe_now) {


err = azx_probe_continue(chip);
if (err < 0)
goto out_free;



--
David Henningsson, Canonical Ltd.
https://launchpad.net/~diwic
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Re: [PATCH 2/2 v2] ALSA: hda - Deferred probing with request_firmware_nowait()

[David Henningsson]

On 08/09/2012 03:36 PM, Takashi Iwai wrote:

+/* callback from request_firmware_nowait() */
+static void azx_firmware_cb(const struct firmware *fw, void *context)
+{
+   struct snd_card *card = context;
+   struct azx *chip = card-private_data;
+   struct pci_dev *pci = chip-pci;
+
+   if (!fw) {
+   snd_printk(KERN_ERR SFX Cannot load firmware, aborting\n);
+   goto error;
+   }


Another thing, aren't you missing a

chip-fw = fw;

here?


+
+   if (!chip-disabled) {
+   /* continue probing */
+   if (azx_probe_continue(chip))
+   goto error;
+   }
+   return; /* OK */
+
+ error:
+   snd_card_free(card);
+   pci_set_drvdata(pci, NULL);
+}
+
  static int __devinit azx_probe(struct pci_dev *pci,
   const struct pci_device_id *pci_id)
  {
static int dev;
struct snd_card *card;
struct azx *chip;
+   bool probe_deferred;
int err;

if (dev = SNDRV_CARDS)
@@ -3182,18 +3211,22 @@ static int __devinit azx_probe(struct pci_dev *pci,
if (err  0)
goto out_free;
card-private_data = chip;


Right, this patch has the race removed, as the variable is no longer set 
in azx_firmware_cb. To be picky, it's slightly confusing that 
probe_deferred is also used for signalling a disabled chip. Maybe 
probe_now (inverted) would have been even better, like this:



+   probe_deferred = chip-disabled;


probe_now = !chip-disabled;



  #ifdef CONFIG_SND_HDA_PATCH_LOADER
if (patch[dev]  *patch[dev]) {


(maybe we should not ask for firmware for a disabled chip either)


snd_printk(KERN_ERR SFX Applying patch firmware '%s'\n,
   patch[dev]);
-   err = request_firmware(chip-fw, patch[dev], pci-dev);
+   err = request_firmware_nowait(THIS_MODULE, true, patch[dev],
+ pci-dev, GFP_KERNEL, card,
+ azx_firmware_cb);
if (err  0)
goto out_free;
+   probe_deferred = true;


probe_now = false;


}
  #endif /* CONFIG_SND_HDA_PATCH_LOADER */

-   if (!chip-disabled) {
+   if (!probe_deferred) {


if (probe_now) {


err = azx_probe_continue(chip);
if (err  0)
goto out_free;



--
David Henningsson, Canonical Ltd.
https://launchpad.net/~diwic
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Re: [PATCH 2/2 v2] ALSA: hda - Deferred probing with request_firmware_nowait()

[Thierry Reding]

On Thu, Aug 09, 2012 at 03:54:04PM +0200, David Henningsson wrote:
 On 08/09/2012 03:36 PM, Takashi Iwai wrote:
 +/* callback from request_firmware_nowait() */
 +static void azx_firmware_cb(const struct firmware *fw, void *context)
 +{
 +struct snd_card *card = context;
 +struct azx *chip = card-private_data;
 +struct pci_dev *pci = chip-pci;
 +
 +if (!fw) {
 +snd_printk(KERN_ERR SFX Cannot load firmware, aborting\n);
 +goto error;
 +}
 
 Another thing, aren't you missing a
 
 chip-fw = fw;
 
 here?

Adding that line here fixes the problem for me.

Thierry


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Re: [PATCH 2/2 v2] ALSA: hda - Deferred probing with request_firmware_nowait()

[Takashi Iwai]

At Thu, 09 Aug 2012 15:54:04 +0200,
David Henningsson wrote:
 
 On 08/09/2012 03:36 PM, Takashi Iwai wrote:
  +/* callback from request_firmware_nowait() */
  +static void azx_firmware_cb(const struct firmware *fw, void *context)
  +{
  +   struct snd_card *card = context;
  +   struct azx *chip = card-private_data;
  +   struct pci_dev *pci = chip-pci;
  +
  +   if (!fw) {
  +   snd_printk(KERN_ERR SFX Cannot load firmware, aborting\n);
  +   goto error;
  +   }
 
 Another thing, aren't you missing a
 
 chip-fw = fw;
 
 here?

Ah, yes.


  +
  +   if (!chip-disabled) {
  +   /* continue probing */
  +   if (azx_probe_continue(chip))
  +   goto error;
  +   }
  +   return; /* OK */
  +
  + error:
  +   snd_card_free(card);
  +   pci_set_drvdata(pci, NULL);
  +}
  +
static int __devinit azx_probe(struct pci_dev *pci,
 const struct pci_device_id *pci_id)
{
  static int dev;
  struct snd_card *card;
  struct azx *chip;
  +   bool probe_deferred;
  int err;
 
  if (dev = SNDRV_CARDS)
  @@ -3182,18 +3211,22 @@ static int __devinit azx_probe(struct pci_dev *pci,
  if (err  0)
  goto out_free;
  card-private_data = chip;
 
 Right, this patch has the race removed, as the variable is no longer set 
 in azx_firmware_cb. To be picky, it's slightly confusing that 
 probe_deferred is also used for signalling a disabled chip. Maybe 
 probe_now (inverted) would have been even better, like this:

Yeah, this looks slightly more straightforward.

I'm going to send a revised version shortly.


thanks,

Takashi
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the body of a message to majord...@vger.kernel.org
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