lkml.org 
[lkml]   [2006]   [Nov]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] ALSA: hda-intel - Disable MSI support by default
Takashi Iwai wrote:
> At Wed, 15 Nov 2006 14:15:45 -0500,
> Jeff Garzik wrote:
>> ACK the pci_intx() calls, NAK the obviously overweight spinlock changes.
>> The spinlock changes are completely unnecessary. Just look at any
>> other (non-ALSA) PCI driver. Existing "spin_lock()" is fine for both
>> PCI shared irq handlers and MSI irq handlers.
>>
>> It sounds like you are trying to work around a reentrancy problem that
>> does not exist.
>>
>> Only weird drivers like ps2kbd/mouse or IDE need spin_lock_irqsave(),
>> where separate interrupt sources call the same function.
>
> OK, I revised it, also referring to a similar patch by Yinghai.
> I think we can simplify the change like below.
> Olivier, could you test this patch, too?

Applied to 2.6.19-rc6, the module tries MSI but this time no IRQ get
disabled. The result is equivalent to 2.6.19-rc6


ALSA sound/pci/hda/hda_intel.c:543: hda_intel: No response from codec,
disabling MSI...
hda_codec: Unknown model for AD1988, trying auto-probe from BIOS...


Full details:
http://olivn.trollprod.com/19-rc6/19-rc6-takashi-routeirq1.dmesg
http://olivn.trollprod.com/19-rc6/19-rc6-takashi-routeirq1.irq

Olivier



>
> (Here the first chunk (enable_msi=1) is just for testing.
> The patch isn't for merge yet.)
>
>
> Takashi
>
> ---
> diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
> index e35cfd3..130ee12 100644
> --- a/sound/pci/hda/hda_intel.c
> +++ b/sound/pci/hda/hda_intel.c
> @@ -55,7 +55,7 @@ static char *model;
> static int position_fix;
> static int probe_mask = -1;
> static int single_cmd;
> -static int enable_msi;
> +static int enable_msi = 1;
>
> module_param(index, int, 0444);
> MODULE_PARM_DESC(index, "Index value for Intel HD audio interface.");
> @@ -1380,7 +1380,8 @@ static int __devinit azx_init_stream(str
>
> static int azx_acquire_irq(struct azx *chip, int do_disconnect)
> {
> - if (request_irq(chip->pci->irq, azx_interrupt, IRQF_DISABLED|IRQF_SHARED,
> + if (request_irq(chip->pci->irq, azx_interrupt,
> + chip->msi ? 0 : IRQF_SHARED,
> "HDA Intel", chip)) {
> printk(KERN_ERR "hda-intel: unable to grab IRQ %d, "
> "disabling device\n", chip->pci->irq);
> @@ -1389,6 +1390,7 @@ static int azx_acquire_irq(struct azx *c
> return -1;
> }
> chip->irq = chip->pci->irq;
> + pci_intx(chi->pci, !chip->msi);
> return 0;
> }
>


--
Laudator temporis acti (Horace, 173)
Donner c'est donner, repeindre ses volets
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2006-11-17 00:03    [W:0.128 / U:28.692 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site