[alsa-devel] [PATCH 0/7] Runtime PM support (hda/tegra)
Background ========== The device power management operations can be controlled with the help of runtime power management (runtime PM) framework. In this case hda driver can register runtime PM callbacks with the power management core (PM core). Idea is to put the device in low power mode, when it is not getting used. The clocks and power domains can be turned off when no use case is running on the device. Current patch series adds necessary support to manage hda device at runtime.
Change log ========== v1: ---- Patch-1: "ALSA: hda/tegra: runtime power management support" * runtime PM enable/disable added in device probe/remove * runtime PM calls are forbidden if AZX_DCAPS_PM_RUNTIME is not enabled in driver flags * worker thread uses pm_runtime_get_sync to invoke ->runtime_resume and pm_runtime_put to invoke ->runtime_suspend. The callbacks are added in subsequent patches
Patch-2: "ALSA: hda/tegra: get clock handles early in probe" * Clock handles required for hda are acquired early in the probe. This is done to make use of runtime PM framework to enable/disable clocks in the callbacks.
Patch-3: "ALSA: hda/tegra: add runtime PM callbacks" * adds runtime PM callbacks for ->runtime_suspend(), ->runtime_resume() * only skeleton for the callbacks is added, implementation is done in the subsequent patches
Patch-4: "ALSA: hda/tegra: remove redundant clock enable API" * As worked thread is calling pm_runtime_get_sync() now, no need to enable the clock explicitly. This can be managed from callback. * Idea is to have clock enable and disable functionalities in runtime PM callbacks and the driver can make use of the above. Any device access should be preceded by ->runtime_resume() call.
Patch-5: "ALSA: hda/tegra: implement runtime suspend/resume" * clock enable and controller initialization is moved to ->runtime_reesume() and the reverse is done during ->runtime_suspend() * Also during system wide power transitions, pm_runtime_force_resume() is invoked in system resume() and similarly for suspend case.
Patch-6: "ALSA: hda/tegra: fix kernel panic" * kernel panic is happening befoe controller init is done * added a flag "probed" to indicate the completion of device init * this flag is checked before doing any device access.
Patch-7: "ALSA: hda/tegra: add driver flag for runtime PM" * driver flag AZX_DCAPS_PM_RUNTIME is added if CONFIG_PM is enabled. * otherwise runtime PM calls will be forbidden and act as dummy calls
=========
Sameer Pujar (7): ALSA: hda/tegra: runtime power management support ALSA: hda/tegra: get clock handles early in probe ALSA: hda/tegra: add runtime PM callbacks ALSA: hda/tegra: remove redundant clock enable API ALSA: hda/tegra: implement runtime suspend/resume ALSA: hda/tegra: fix kernel panic ALSA: hda/tegra: add driver flag for runtime PM
sound/pci/hda/hda_tegra.c | 120 +++++++++++++++++++++++++++++++++------------- 1 file changed, 88 insertions(+), 32 deletions(-)
This patch enables runtime power management(runtime PM) support for hda. pm_runtime_enable() and pm_runtime_disable() are added during device probe and remove respectively. The runtime PM callbacks will be forbidden if hda controller does not have support for runtime PM. pm_runtime_get_sync() and pm_runtime_put() are added for hda register access. The callbacks for above will be added in subsequent patches.
Signed-off-by: Sameer Pujar spujar@nvidia.com Reviewed-by: Ravindra Lokhande rlokhande@nvidia.com Reviewed-by: Mohan Kumar D mkumard@nvidia.com --- sound/pci/hda/hda_tegra.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/sound/pci/hda/hda_tegra.c b/sound/pci/hda/hda_tegra.c index 97a176d..2f9dd23 100644 --- a/sound/pci/hda/hda_tegra.c +++ b/sound/pci/hda/hda_tegra.c @@ -32,6 +32,7 @@ #include <linux/slab.h> #include <linux/time.h> #include <linux/string.h> +#include <linux/pm_runtime.h>
#include <sound/core.h> #include <sound/initval.h> @@ -512,6 +513,11 @@ static int hda_tegra_probe(struct platform_device *pdev) card->private_data = chip;
dev_set_drvdata(&pdev->dev, card); + + pm_runtime_enable(hda->dev); + if (!azx_has_pm_runtime(chip)) + pm_runtime_forbid(hda->dev); + schedule_work(&hda->probe_work);
return 0; @@ -528,6 +534,7 @@ static void hda_tegra_probe_work(struct work_struct *work) struct platform_device *pdev = to_platform_device(hda->dev); int err;
+ pm_runtime_get_sync(hda->dev); err = hda_tegra_first_init(chip, pdev); if (err < 0) goto out_free; @@ -549,12 +556,18 @@ static void hda_tegra_probe_work(struct work_struct *work) snd_hda_set_power_save(&chip->bus, power_save * 1000);
out_free: + pm_runtime_put(hda->dev); return; /* no error return from async probe */ }
static int hda_tegra_remove(struct platform_device *pdev) { - return snd_card_free(dev_get_drvdata(&pdev->dev)); + int ret; + + ret = snd_card_free(dev_get_drvdata(&pdev->dev)); + pm_runtime_disable(&pdev->dev); + + return ret; }
static void hda_tegra_shutdown(struct platform_device *pdev)
Moved devm_clk_get() API calls to a separate function and the same can be called early in the probe. This is done before runtime PM for the device is enabled. The runtime resume/suspend callbacks can later enable/disable clocks respectively(the support would be added in subsequent patches). Clock handles should be available by the time runtime suspend/resume calls can happen.
Signed-off-by: Sameer Pujar spujar@nvidia.com Reviewed-by: Ravindra Lokhande rlokhande@nvidia.com Reviewed-by: Mohan Kumar D mkumard@nvidia.com --- sound/pci/hda/hda_tegra.c | 43 +++++++++++++++++++++++++++---------------- 1 file changed, 27 insertions(+), 16 deletions(-)
diff --git a/sound/pci/hda/hda_tegra.c b/sound/pci/hda/hda_tegra.c index 2f9dd23..28e1656 100644 --- a/sound/pci/hda/hda_tegra.c +++ b/sound/pci/hda/hda_tegra.c @@ -306,22 +306,6 @@ static int hda_tegra_init_chip(struct azx *chip, struct platform_device *pdev) struct resource *res; int err;
- hda->hda_clk = devm_clk_get(dev, "hda"); - if (IS_ERR(hda->hda_clk)) { - dev_err(dev, "failed to get hda clock\n"); - return PTR_ERR(hda->hda_clk); - } - hda->hda2codec_2x_clk = devm_clk_get(dev, "hda2codec_2x"); - if (IS_ERR(hda->hda2codec_2x_clk)) { - dev_err(dev, "failed to get hda2codec_2x clock\n"); - return PTR_ERR(hda->hda2codec_2x_clk); - } - hda->hda2hdmi_clk = devm_clk_get(dev, "hda2hdmi"); - if (IS_ERR(hda->hda2hdmi_clk)) { - dev_err(dev, "failed to get hda2hdmi clock\n"); - return PTR_ERR(hda->hda2hdmi_clk); - } - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); hda->regs = devm_ioremap_resource(dev, res); if (IS_ERR(hda->regs)) @@ -341,6 +325,29 @@ static int hda_tegra_init_chip(struct azx *chip, struct platform_device *pdev) return 0; }
+static int hda_tegra_init_clk(struct hda_tegra *hda) +{ + struct device *dev = hda->dev; + + hda->hda_clk = devm_clk_get(dev, "hda"); + if (IS_ERR(hda->hda_clk)) { + dev_err(dev, "failed to get hda clock\n"); + return PTR_ERR(hda->hda_clk); + } + hda->hda2codec_2x_clk = devm_clk_get(dev, "hda2codec_2x"); + if (IS_ERR(hda->hda2codec_2x_clk)) { + dev_err(dev, "failed to get hda2codec_2x clock\n"); + return PTR_ERR(hda->hda2codec_2x_clk); + } + hda->hda2hdmi_clk = devm_clk_get(dev, "hda2hdmi"); + if (IS_ERR(hda->hda2hdmi_clk)) { + dev_err(dev, "failed to get hda2hdmi clock\n"); + return PTR_ERR(hda->hda2hdmi_clk); + } + + return 0; +} + static int hda_tegra_first_init(struct azx *chip, struct platform_device *pdev) { struct hdac_bus *bus = azx_bus(chip); @@ -507,6 +514,10 @@ static int hda_tegra_probe(struct platform_device *pdev) return err; }
+ err = hda_tegra_init_clk(hda); + if (err < 0) + goto out_free; + err = hda_tegra_create(card, driver_flags, hda); if (err < 0) goto out_free;
This patch adds skeleton of runtime suspend and resume callbacks.
Signed-off-by: Sameer Pujar spujar@nvidia.com Reviewed-by: Ravindra Lokhande rlokhande@nvidia.com Reviewed-by: Mohan Kumar D mkumard@nvidia.com --- sound/pci/hda/hda_tegra.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+)
diff --git a/sound/pci/hda/hda_tegra.c b/sound/pci/hda/hda_tegra.c index 28e1656..1189f97 100644 --- a/sound/pci/hda/hda_tegra.c +++ b/sound/pci/hda/hda_tegra.c @@ -265,8 +265,23 @@ static int hda_tegra_resume(struct device *dev) } #endif /* CONFIG_PM_SLEEP */
+#ifdef CONFIG_PM +static int hda_tegra_runtime_suspend(struct device *dev) +{ + return 0; +} + +static int hda_tegra_runtime_resume(struct device *dev) +{ + return 0; +} +#endif /* CONFIG_PM */ + static const struct dev_pm_ops hda_tegra_pm = { SET_SYSTEM_SLEEP_PM_OPS(hda_tegra_suspend, hda_tegra_resume) + SET_RUNTIME_PM_OPS(hda_tegra_runtime_suspend, + hda_tegra_runtime_resume, + NULL) };
static int hda_tegra_dev_disconnect(struct snd_device *device)
Explicit clock enable is not required during probe, as this would be managed by runtime PM calls. Clock can be enabled/disabled in runtime resume/suspend. This way it is easier to balance clock enable/disable counts.
Signed-off-by: Sameer Pujar spujar@nvidia.com Reviewed-by: Ravindra Lokhande rlokhande@nvidia.com Reviewed-by: Mohan Kumar D mkumard@nvidia.com --- sound/pci/hda/hda_tegra.c | 7 ------- 1 file changed, 7 deletions(-)
diff --git a/sound/pci/hda/hda_tegra.c b/sound/pci/hda/hda_tegra.c index 1189f97..f068b1e 100644 --- a/sound/pci/hda/hda_tegra.c +++ b/sound/pci/hda/hda_tegra.c @@ -319,7 +319,6 @@ static int hda_tegra_init_chip(struct azx *chip, struct platform_device *pdev) struct hdac_bus *bus = azx_bus(chip); struct device *dev = hda->dev; struct resource *res; - int err;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0); hda->regs = devm_ioremap_resource(dev, res); @@ -329,12 +328,6 @@ static int hda_tegra_init_chip(struct azx *chip, struct platform_device *pdev) bus->remap_addr = hda->regs + HDA_BAR0; bus->addr = res->start + HDA_BAR0;
- err = hda_tegra_enable_clocks(hda); - if (err) { - dev_err(dev, "failed to get enable clocks\n"); - return err; - } - hda_tegra_init(hda);
return 0;
This patch moves clock enable/disable from system resume/suspend to runtime resume/suspend respectively. Along with this hda controller chip init or stop is also moved. System resume/suspend can invoke runtime callbacks and do necessary setup.
Signed-off-by: Sameer Pujar spujar@nvidia.com Reviewed-by: Ravindra Lokhande rlokhande@nvidia.com Reviewed-by: Mohan Kumar D mkumard@nvidia.com --- sound/pci/hda/hda_tegra.c | 45 +++++++++++++++++++++++++++++---------------- 1 file changed, 29 insertions(+), 16 deletions(-)
diff --git a/sound/pci/hda/hda_tegra.c b/sound/pci/hda/hda_tegra.c index f068b1e..5546e29 100644 --- a/sound/pci/hda/hda_tegra.c +++ b/sound/pci/hda/hda_tegra.c @@ -233,32 +233,24 @@ static void hda_tegra_disable_clocks(struct hda_tegra *data) static int hda_tegra_suspend(struct device *dev) { struct snd_card *card = dev_get_drvdata(dev); - struct azx *chip = card->private_data; - struct hda_tegra *hda = container_of(chip, struct hda_tegra, chip); - struct hdac_bus *bus = azx_bus(chip); + int rc;
+ rc = pm_runtime_force_suspend(dev); + if (rc < 0) + return rc; snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
- azx_stop_chip(chip); - synchronize_irq(bus->irq); - azx_enter_link_reset(chip); - hda_tegra_disable_clocks(hda); - return 0; }
static int hda_tegra_resume(struct device *dev) { struct snd_card *card = dev_get_drvdata(dev); - struct azx *chip = card->private_data; - struct hda_tegra *hda = container_of(chip, struct hda_tegra, chip); - - hda_tegra_enable_clocks(hda); - - hda_tegra_init(hda); - - azx_init_chip(chip, 1); + int rc;
+ rc = pm_runtime_force_resume(dev); + if (rc < 0) + return rc; snd_power_change_state(card, SNDRV_CTL_POWER_D0);
return 0; @@ -268,11 +260,32 @@ static int hda_tegra_resume(struct device *dev) #ifdef CONFIG_PM static int hda_tegra_runtime_suspend(struct device *dev) { + struct snd_card *card = dev_get_drvdata(dev); + struct azx *chip = card->private_data; + struct hda_tegra *hda = container_of(chip, struct hda_tegra, chip); + struct hdac_bus *bus = azx_bus(chip); + + azx_stop_chip(chip); + synchronize_irq(bus->irq); + azx_enter_link_reset(chip); + hda_tegra_disable_clocks(hda); + return 0; }
static int hda_tegra_runtime_resume(struct device *dev) { + struct snd_card *card = dev_get_drvdata(dev); + struct azx *chip = card->private_data; + struct hda_tegra *hda = container_of(chip, struct hda_tegra, chip); + int rc; + + rc = hda_tegra_enable_clocks(hda); + if (rc != 0) + return rc; + hda_tegra_init(hda); + azx_init_chip(chip, 1); + return 0; } #endif /* CONFIG_PM */
Kernel panic is seen during device boot. It appears that before the probe completes, runtime callbacks happen and the device setup is not done yet. This could be initiated from framework through exposed callbacks. This issue can be fixed by having a flag to indicate completion of device probe. Hence 'probed' flag is introduced to notify completion of probe and runtime callbacks can check this flag before doing any device access.
Signed-off-by: Sameer Pujar spujar@nvidia.com Reviewed-by: Ravindra Lokhande rlokhande@nvidia.com Reviewed-by: Mohan Kumar D mkumard@nvidia.com --- sound/pci/hda/hda_tegra.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-)
diff --git a/sound/pci/hda/hda_tegra.c b/sound/pci/hda/hda_tegra.c index 5546e29..80c4042 100644 --- a/sound/pci/hda/hda_tegra.c +++ b/sound/pci/hda/hda_tegra.c @@ -76,6 +76,7 @@ struct hda_tegra { struct clk *hda2hdmi_clk; void __iomem *regs; struct work_struct probe_work; + bool probed; };
#ifdef CONFIG_PM @@ -265,9 +266,11 @@ static int hda_tegra_runtime_suspend(struct device *dev) struct hda_tegra *hda = container_of(chip, struct hda_tegra, chip); struct hdac_bus *bus = azx_bus(chip);
- azx_stop_chip(chip); - synchronize_irq(bus->irq); - azx_enter_link_reset(chip); + if (hda->probed) { + azx_stop_chip(chip); + synchronize_irq(bus->irq); + azx_enter_link_reset(chip); + } hda_tegra_disable_clocks(hda);
return 0; @@ -283,8 +286,10 @@ static int hda_tegra_runtime_resume(struct device *dev) rc = hda_tegra_enable_clocks(hda); if (rc != 0) return rc; - hda_tegra_init(hda); - azx_init_chip(chip, 1); + if (hda->probed) { + hda_tegra_init(hda); + azx_init_chip(chip, 1); + }
return 0; } @@ -527,6 +532,7 @@ static int hda_tegra_probe(struct platform_device *pdev) return -ENOMEM; hda->dev = &pdev->dev; chip = &hda->chip; + hda->probed = false;
err = snd_card_new(&pdev->dev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1, THIS_MODULE, 0, &card); @@ -585,6 +591,7 @@ static void hda_tegra_probe_work(struct work_struct *work) goto out_free;
chip->running = 1; + hda->probed = true; snd_hda_set_power_save(&chip->bus, power_save * 1000);
out_free:
On Mon, 21 Jan 2019 18:41:36 +0100, Sameer Pujar wrote:
Kernel panic is seen during device boot. It appears that before the probe completes, runtime callbacks happen and the device setup is not done yet. This could be initiated from framework through exposed callbacks. This issue can be fixed by having a flag to indicate completion of device probe. Hence 'probed' flag is introduced to notify completion of probe and runtime callbacks can check this flag before doing any device access.
Such a fix should be rather folded into the previous, especially if you know it's already broken :)
And, IMO, it's better to put such a check into runtime_idle callback instead of doing in each (runtime_)suspend/resume callback.
thanks,
Takashi
On 1/22/2019 2:58 AM, Takashi Iwai wrote:
On Mon, 21 Jan 2019 18:41:36 +0100, Sameer Pujar wrote:
Kernel panic is seen during device boot. It appears that before the probe completes, runtime callbacks happen and the device setup is not done yet. This could be initiated from framework through exposed callbacks. This issue can be fixed by having a flag to indicate completion of device probe. Hence 'probed' flag is introduced to notify completion of probe and runtime callbacks can check this flag before doing any device access.
Such a fix should be rather folded into the previous, especially if you know it's already broken :)
Ok, I will meld this with previous commit.
And, IMO, it's better to put such a check into runtime_idle callback instead of doing in each (runtime_)suspend/resume callback.
Check in runtime_idle would take care of suspend path. But how the check in runtime_resume can be avoided? Kernel panic happened during runtime_resume().
thanks,
Takashi
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On Tue, 22 Jan 2019 04:41:16 +0100, Sameer Pujar wrote:
On 1/22/2019 2:58 AM, Takashi Iwai wrote:
On Mon, 21 Jan 2019 18:41:36 +0100, Sameer Pujar wrote:
Kernel panic is seen during device boot. It appears that before the probe completes, runtime callbacks happen and the device setup is not done yet. This could be initiated from framework through exposed callbacks. This issue can be fixed by having a flag to indicate completion of device probe. Hence 'probed' flag is introduced to notify completion of probe and runtime callbacks can check this flag before doing any device access.
Such a fix should be rather folded into the previous, especially if you know it's already broken :)
Ok, I will meld this with previous commit.
And, IMO, it's better to put such a check into runtime_idle callback instead of doing in each (runtime_)suspend/resume callback.
Check in runtime_idle would take care of suspend path. But how the check in runtime_resume can be avoided? Kernel panic happened during runtime_resume().
Hm, right, we need the check in both places, since runtime PM is called from the system PM, too.
BTW, I guess we can check chip->running instead of adding a new flag.
thanks,
Takashi
AZX_DCAPS_PM_RUNTIME flag is added to indicate support for runtime PM. azx_has_pm_runtime() can be called to check if above is enabled. The flag is put under CONFIG_PM check.
Signed-off-by: Sameer Pujar spujar@nvidia.com Reviewed-by: Ravindra Lokhande rlokhande@nvidia.com Reviewed-by: Mohan Kumar D mkumard@nvidia.com --- sound/pci/hda/hda_tegra.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/sound/pci/hda/hda_tegra.c b/sound/pci/hda/hda_tegra.c index 80c4042..80b7a3b 100644 --- a/sound/pci/hda/hda_tegra.c +++ b/sound/pci/hda/hda_tegra.c @@ -521,12 +521,16 @@ MODULE_DEVICE_TABLE(of, hda_tegra_match);
static int hda_tegra_probe(struct platform_device *pdev) { - const unsigned int driver_flags = AZX_DCAPS_CORBRP_SELF_CLEAR; + unsigned int driver_flags = AZX_DCAPS_CORBRP_SELF_CLEAR; struct snd_card *card; struct azx *chip; struct hda_tegra *hda; int err;
+#ifdef CONFIG_PM + driver_flags |= AZX_DCAPS_PM_RUNTIME; +#endif + hda = devm_kzalloc(&pdev->dev, sizeof(*hda), GFP_KERNEL); if (!hda) return -ENOMEM;
On Mon, 21 Jan 2019 18:41:37 +0100, Sameer Pujar wrote:
AZX_DCAPS_PM_RUNTIME flag is added to indicate support for runtime PM. azx_has_pm_runtime() can be called to check if above is enabled. The flag is put under CONFIG_PM check.
Signed-off-by: Sameer Pujar spujar@nvidia.com Reviewed-by: Ravindra Lokhande rlokhande@nvidia.com Reviewed-by: Mohan Kumar D mkumard@nvidia.com
This can be more simply done in hda_controller.h. Namely, a change like:
--- a/sound/pci/hda/hda_controller.h +++ b/sound/pci/hda/hda_controller.h @@ -49,7 +49,11 @@ #define AZX_DCAPS_4K_BDLE_BOUNDARY (1 << 23) /* BDLE in 4k boundary */ /* 24 unused */ #define AZX_DCAPS_COUNT_LPIB_DELAY (1 << 25) /* Take LPIB as delay */ +#ifdef CONFIG_PM #define AZX_DCAPS_PM_RUNTIME (1 << 26) /* runtime PM support */ +#else +#define AZX_DCAPS_PM_RUNTIME 0 /* N/A */ +#endif /* 27 unused */ #define AZX_DCAPS_CORBRP_SELF_CLEAR (1 << 28) /* CORBRP clears itself after reset */ #define AZX_DCAPS_NO_MSI64 (1 << 29) /* Stick to 32-bit MSIs */
thanks,
Takashi
On 1/22/2019 3:01 AM, Takashi Iwai wrote:
On Mon, 21 Jan 2019 18:41:37 +0100, Sameer Pujar wrote:
AZX_DCAPS_PM_RUNTIME flag is added to indicate support for runtime PM. azx_has_pm_runtime() can be called to check if above is enabled. The flag is put under CONFIG_PM check.
Signed-off-by: Sameer Pujar spujar@nvidia.com Reviewed-by: Ravindra Lokhande rlokhande@nvidia.com Reviewed-by: Mohan Kumar D mkumard@nvidia.com
This can be more simply done in hda_controller.h. Namely, a change like:
--- a/sound/pci/hda/hda_controller.h +++ b/sound/pci/hda/hda_controller.h @@ -49,7 +49,11 @@ #define AZX_DCAPS_4K_BDLE_BOUNDARY (1 << 23) /* BDLE in 4k boundary */ /* 24 unused */ #define AZX_DCAPS_COUNT_LPIB_DELAY (1 << 25) /* Take LPIB as delay */ +#ifdef CONFIG_PM #define AZX_DCAPS_PM_RUNTIME (1 << 26) /* runtime PM support */ +#else +#define AZX_DCAPS_PM_RUNTIME 0 /* N/A */ +#endif /* 27 unused */ #define AZX_DCAPS_CORBRP_SELF_CLEAR (1 << 28) /* CORBRP clears itself after reset */ #define AZX_DCAPS_NO_MSI64 (1 << 29) /* Stick to 32-bit MSIs */
In one of the patches in the series, I am using azx_has_pm_runtime() to forbid runtime PM calls. I can use above as you suggested. Along with this, I would need to populate chip->driver_caps with above flag. Something like below,
--- a/sound/pci/hda/hda_tegra.c +++ b/sound/pci/hda/hda_tegra.c @@ -521,7 +521,8 @@ MODULE_DEVICE_TABLE(of, hda_tegra_match);
static int hda_tegra_probe(struct platform_device *pdev) { - unsigned int driver_flags = AZX_DCAPS_CORBRP_SELF_CLEAR; + unsigned int driver_flags = AZX_DCAPS_CORBRP_SELF_CLEAR | + AZX_DCAPS_PM_RUNTIME; struct snd_card *card; struct azx *chip; struct hda_tegra *hda;
Thanks, Sameer.
thanks,
Takashi
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On Tue, 22 Jan 2019 03:04:21 +0100, Sameer Pujar wrote:
On 1/22/2019 3:01 AM, Takashi Iwai wrote:
On Mon, 21 Jan 2019 18:41:37 +0100, Sameer Pujar wrote:
AZX_DCAPS_PM_RUNTIME flag is added to indicate support for runtime PM. azx_has_pm_runtime() can be called to check if above is enabled. The flag is put under CONFIG_PM check.
Signed-off-by: Sameer Pujar spujar@nvidia.com Reviewed-by: Ravindra Lokhande rlokhande@nvidia.com Reviewed-by: Mohan Kumar D mkumard@nvidia.com
This can be more simply done in hda_controller.h. Namely, a change like:
--- a/sound/pci/hda/hda_controller.h +++ b/sound/pci/hda/hda_controller.h @@ -49,7 +49,11 @@ #define AZX_DCAPS_4K_BDLE_BOUNDARY (1 << 23) /* BDLE in 4k boundary */ /* 24 unused */ #define AZX_DCAPS_COUNT_LPIB_DELAY (1 << 25) /* Take LPIB as delay */ +#ifdef CONFIG_PM #define AZX_DCAPS_PM_RUNTIME (1 << 26) /* runtime PM support */ +#else +#define AZX_DCAPS_PM_RUNTIME 0 /* N/A */ +#endif /* 27 unused */ #define AZX_DCAPS_CORBRP_SELF_CLEAR (1 << 28) /* CORBRP clears itself after reset */ #define AZX_DCAPS_NO_MSI64 (1 << 29) /* Stick to 32-bit MSIs */
In one of the patches in the series, I am using azx_has_pm_runtime() to forbid runtime PM calls. I can use above as you suggested. Along with this, I would need to populate chip->driver_caps with above flag. Something like below,
--- a/sound/pci/hda/hda_tegra.c +++ b/sound/pci/hda/hda_tegra.c @@ -521,7 +521,8 @@ MODULE_DEVICE_TABLE(of, hda_tegra_match);
static int hda_tegra_probe(struct platform_device *pdev) { - unsigned int driver_flags = AZX_DCAPS_CORBRP_SELF_CLEAR; + unsigned int driver_flags = AZX_DCAPS_CORBRP_SELF_CLEAR | + AZX_DCAPS_PM_RUNTIME; struct snd_card *card; struct azx *chip; struct hda_tegra *hda;
I see. On the second thought, the ifdef CONFIG_PM is likely superfluous. The whole pm_runtime_*() calls become no-ops without CONFIG_PM, so the compiler would optimize in anyway.
That said, I'd drop ugly ifdef but unconditionally add AZX_DCAPS_PM_RUNTIME in an oneliner above.
thanks,
Takashi
participants (2)
-
Sameer Pujar -
Takashi Iwai