Re: [PATCH v3 08/14] ASoC: SOF: Add DSP HW abstraction operations

[Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>]

On 1/9/19 2:51 PM, Mark Brown wrote:
> On Tue, Dec 11, 2018 at 03:23:12PM -0600, Pierre-Louis Bossart wrote:
>
>> +int snd_sof_pci_update_bits_unlocked(struct snd_sof_dev *sdev, u32 offset,
>> +				     u32 mask, u32 value)
>> +{
>> +	bool change;
>> +	unsigned int old, new;
>> +	u32 ret = ~0; /* explicit init to remove uninitialized use warnings */
> This looks a lot like you want to write regmap_pci_config...

I think you made that note for the v2 a long time ago, not sure if I 
replied at the time.

We only use this for 4 cases (power/clock gating on/off, traffic class, 
etc) and only during the hardware initialization. This is similar to the 
legacy and Skylake driver, I don't see a significant benefit with a regmap?

intel/hda-ctrl.c:       snd_sof_pci_update_bits(sdev, PCI_CGCTL, 
PCI_CGCTL_MISCBDCGE_MASK, val);
intel/hda-ctrl.c:       snd_sof_pci_update_bits(sdev, PCI_CGCTL, 
PCI_CGCTL_ADSPDCGE, val);
intel/hda-ctrl.c:       snd_sof_pci_update_bits(sdev, PCI_PGCTL, 
PCI_PGCTL_ADSPPGD, val);
intel/hda-dsp.c:        snd_sof_pci_update_bits(sdev, PCI_PGCTL,
intel/hda-dsp.c:        snd_sof_pci_update_bits(sdev, PCI_TCSEL, 0x07, 0);

>
>> +/* control */
>> +static inline int snd_sof_dsp_run(struct snd_sof_dev *sdev)
>> +{
>> +	if (sdev->ops->run)
>> +		return sdev->ops->run(sdev);
>> +
>> +	return 0;
>> +}
> Do we really want to return 0 for all these ops if they're not
> implemented?  For some that seems sensible but there's others where it
> seems like the caller might want to know they got ignored and an error
> code like -ENOTSUPP might be better.
Good point indeed. There are a set of ops that are really mandatory, we 
should rework this instead. Thanks for the comment.