[alsa-devel] Codec driver gets probed prior to the machine driver
Hi,
When running linux-next 20130607 on a mx6qsabrelite I see that the audio drivers fail to probe. Added some printk's to better illustrate the problem:
mmcblk0: mmc0:b5a1 SD04G 3.69 GiB **** reading the chip ID sgtl5000: probe of 0-000a failed with error -5 ****** enabling the codec clock imx-sgtl5000 sound.13: ASoC: CODEC (null) not registered imx-sgtl5000 sound.13: snd_soc_register_card failed (-517) platform sound.13: Driver imx-sgtl5000 requests probe defer
The problem here is that the codec driver (sgtl5000) is being probed prior to the machine driver (imx-sgtl5000).
The reading of the chip ID fails because at this point in time there is no codec clock, which is turned on by imx-sgtl5000.
Running 3.10-rc4, the order of the events is as expected: imx-sgtl5000 is called first and sgtl5000 is called later. In this case the probe works as usual.
Tried doing a bisect, but this was not succesful due to several bisect breakages (build issues and non-booting kernels) on its way.
Would anyone have some suggestion as to why the codec driver is getting probed first?
Thanks,
Fabio Estevam
On 06/09/2013 04:50 PM, Fabio Estevam wrote:
Hi,
When running linux-next 20130607 on a mx6qsabrelite I see that the audio drivers fail to probe. Added some printk's to better illustrate the problem:
mmcblk0: mmc0:b5a1 SD04G 3.69 GiB **** reading the chip ID sgtl5000: probe of 0-000a failed with error -5 ****** enabling the codec clock imx-sgtl5000 sound.13: ASoC: CODEC (null) not registered imx-sgtl5000 sound.13: snd_soc_register_card failed (-517) platform sound.13: Driver imx-sgtl5000 requests probe defer
The problem here is that the codec driver (sgtl5000) is being probed prior to the machine driver (imx-sgtl5000).
The reading of the chip ID fails because at this point in time there is no codec clock, which is turned on by imx-sgtl5000.
This sounds as if the CODEC driver should enable the CODEC clock and not the machine driver.
Running 3.10-rc4, the order of the events is as expected: imx-sgtl5000 is called first and sgtl5000 is called later. In this case the probe works as usual.
There are two probe functions one for the i2c driver, one for the codec. The I2C driver probe will be called as soon as the I2C device gets registered. The codec probe will be called once all components for the ASoC sound card (CPU DAI, codec, platform) are ready. Since you are checking the ID in the I2C probe callback there is no guarantee that it will be called before or after the machine driver will be probed.
Tried doing a bisect, but this was not succesful due to several bisect breakages (build issues and non-booting kernels) on its way.
Well, your commit b871f1ad ("ASoC: sgtl5000: Read SGTL5000_CHIP_ID in i2c_probe") moved things around. From one probe callback to the other.
- Lars
Hi Lars-Peter,
On Sun, Jun 9, 2013 at 12:12 PM, Lars-Peter Clausen lars@metafoo.de wrote:
This sounds as if the CODEC driver should enable the CODEC clock and not the machine driver.
Thanks, this works fine. Will send the patches soon.
Thanks for your help.
Fabio Estevam
On Sun, Jun 09, 2013 at 05:12:57PM +0200, Lars-Peter Clausen wrote:
On 06/09/2013 04:50 PM, Fabio Estevam wrote:
The reading of the chip ID fails because at this point in time there is no codec clock, which is turned on by imx-sgtl5000.
This sounds as if the CODEC driver should enable the CODEC clock and not the machine driver.
Well, probably both. Remember that we don't actually have a standard clock API, even the generic clock API is not available on most platforms. Though frankly I'm getting fed up enough with this to just start using the API and getting platforms that haven't provided one to deal with the issue since otherwise I'm getting very little traction.
participants (3)
-
Fabio Estevam -
Lars-Peter Clausen -
Mark Brown