On Wed, Dec 19, 2018 at 08:04:35AM -0600, Pierre-Louis Bossart wrote:
On 12/19/18 7:07 AM, Stephan Gerhold wrote:
On Mon, Dec 17, 2018 at 08:13:36PM -0600, Pierre-Louis Bossart wrote:
> The quirks to get sound working with bytcr-rt5640 on that device are: > BYT_RT5640_SSP0_AIF1 | BYT_RT5640_IN1_MAP | BYT_RT5640_MCLK_EN > > I guess this means that SSP0 is being used? Yes indeed, and that makes me think we should force this device to look like Baytrail-CR.
You can do this with a DMI-based quirk (preferably in is_byt_cr directly so that I can reuse the code when I move it to a helper at some point).
Okay - thanks! One last question: I was looking at the ACPI DSDT tables of some similar devices and have found two others that look the same (only one IRQ listed). In this case, the BYT-T acpi_ipc_irq_index = 5 will never work, and we will definitely have a better chances with trying Baytrail-CR.
One of them actually had a similar patch proposed at [1] (although they did it in a weird way and also need an extra machine driver).
We could also detect this situation in a generic way with something like
if (platform_irq_count(pdev) == 1) { *bytcr = true;return 0; }
... instead of a DMI quirk. What do you think?
To avoid confusion: The existing PMIC-type based is_byt_cr() detection would be used in all other cases (i.e. if irq_count != 1), so it won't make any difference for the devices that are already working fine. (Most BYT-CR devices seem to have 5 IRQs listed)
So it's more like
if (platform_irq_count(pdev) == 1) { *bytcr = true; } else { // pmic-type based detection... }with platform_irq_count == 1 as condition for the "quirk".
The solution seems appealing but
- does it really work? I am not sure an index=5 means there are 5
interrupts.
Yes, I believe that it means that there need to be (at least) 5 interrupts.
I have checked the source code of platform_get_irq. When you do platform_get_irq(pdev, /* index = */ 5) (as done for BYT-T) it first calls
platform_get_resource(/* type = */ IORESOURCE_IRQ, /* num = */ 5)to lookup the resource. That method is really simple and looks like
for (i = 0; i < dev->num_resources; i++) { struct resource *r = &dev->resource[i];
if (type == resource_type(r) && num-- == 0) return r;}
So when you request an IRQ at index=5, it loops through all resources, skips the first 5 IRQs and returns the 6th one (on my device, it returns NULL because there are not enough IRQs listed).
There is a bit more magic in platform_irq_count (it looks up all IRQs and does not count invalid ones), so to be absolutely safe we could just check platform_get_resource(IRQ, 5) == NULL early. If it returns NULL, then platform_get_irq(pdev, 5) will also return -ENXIO, so treating the device as BYT-T is guaranteed to fail. In this case, we have better chances when we assume BYT-CR.
Example patch: (I have added it in probe instead of is_byt_cr() because it requires the platform device, plus I think it might be better to differentiate the messages in the kernel log..)
--- a/sound/soc/intel/atom/sst/sst_acpi.c +++ b/sound/soc/intel/atom/sst/sst_acpi.c @@ -337,6 +337,16 @@ static int sst_acpi_probe(struct platform_device *pdev) if (!((ret < 0) || (bytcr == false))) { dev_info(dev, "Detected Baytrail-CR platform\n");
/* override resource info */ byt_rvp_platform_data.res_info = &bytcr_res_info;
- } else if (platform_get_resource(pdev, IORESOURCE_IRQ, 5) == NULL) {
/** Some devices detected as BYT-T have only a single IRQ listed.* In this case, platform_get_irq with index 5 will return -ENXIO.* Fall back to the BYT-CR resource info to use the correct IRQ.*/dev_info(dev, "Falling back to Baytrail-CR platform\n");/* override resource info */byt_rvp_platform_data.res_info = &bytcr_res_info;
- the test would affect all existing devices, and there's so much hardware
proliferation that proving this change in harmless might be difficult. I personally only have one BYT-T (ASus T100) device left and it's not very reliable. Hans seems to have a ton of devices but they are mostly Byt-Cr?
With the updated patch above I believe there is literally no way this can break sound on any device. The condition only evaluates to true if SST would normally fail to probe later anyway.
I have tested the patch above on my device with:
- as-is, without any modifications: -> "Falling back to Baytrail-CR platform", sound now working
- a simulated "BYT-T" device: (copied the IRQs from the DSDT of the T100TA) -> "BYT-CR not detected" - uses 5th IRQ, sound working
- a simulated "BYT-CR" device (made is_byt_cr() return "true" and copied the IRQs from the DSDT of the T100TAF) -> "Detected Baytrail-CR platform" - uses IRQ at index 0, sound working
Let me know what you think!
Sounds good, playing with resources is what I had in mind rather than an interrupt count which isn't necessarily safe. The only improvement I would suggest is to add this test inside of is_byt_cr(). This routine will be moved as a helper outside of sst_acpi to be reused for SOF, so if we can make this test more self-contained it's more future-proof.
Hmm. Part of why I put it outside of is_byt_cr() is so that the pmic-type based detection always runs, and my new check is only used as a fallback. That allows us to see in the log if the device was detected as BYT-CR through the pmic detection or if BYT-CR is just used as fallback. (Might be useful for troubleshooting in the future..)
The design of is_byt_cr() with multiple returns (and even more so the SOF refactored version at [1]) makes it a bit difficult for me to apply this fallback after the detection, at least if this is supposed to be a single method.
So we can either
(1) Skip pmic-based detection if platform_get_resource(pdev, IORESOURCE_IRQ, 5) == NULL:
--- a/sound/soc/intel/atom/sst/sst_acpi.c +++ b/sound/soc/intel/atom/sst/sst_acpi.c @@ -255,10 +255,18 @@ static int is_byt(void) return status; }
-static int is_byt_cr(struct device *dev, bool *bytcr) +static int is_byt_cr(struct platform_device *pdev, bool *bytcr) { + struct device *dev = &pdev->dev; int status = 0;
+ if (platform_get_resource(pdev, IORESOURCE_IRQ, 5) == NULL) { + /* This message is even shown if the device would be detected as BYT-CR below */ + dev_info(dev, "Falling back to Baytrail-CR platform\n"); + *bytcr = true; + return status; + } + if (IS_ENABLED(CONFIG_IOSF_MBI)) { u32 bios_status;
or (2) Rename is_byt_cr() to something like is_bytcr_pmic() and wrap it with a new method:
static int is_byt_cr(struct platform_device *pdev, bool *bytcr) { int status = is_byt_cr_pmic(&pdev->dev, bytcr); if (!*bytcr && platform_get_resource(pdev, IORESOURCE_IRQ, 5) == NULL) { *bytcr = true; dev_info(&pdev->dev, "Falling back to Baytrail-CR platform\n"); return 0; } return status; }
The end result is the same. The only difference is if we also log the result of the pmic-based detection.
Which one do you prefer? (Or any other suggestions?)
[1]: https://github.com/thesofproject/linux/blob/43b4e383f85446a7f43f7fd19f382d34...