On 12/11/23 15:42, James Clark wrote:
On 11/12/2023 07:51, Anshuman Khandual wrote:
On 12/8/23 11:09, Anshuman Khandual wrote:
Add support for the dynamic replicator device in the platform driver, which can then be used on ACPI based platforms. This change would now allow runtime power management for repliacator devices on ACPI based systems.
The driver would try to enable the APB clock if available. Also, rename the code to reflect the fact that it now handles both static and dynamic replicators.
Cc: Lorenzo Pieralisi lpieralisi@kernel.org Cc: Sudeep Holla sudeep.holla@arm.com Cc: Suzuki K Poulose suzuki.poulose@arm.com Cc: Mike Leach mike.leach@linaro.org Cc: James Clark james.clark@arm.com Cc: linux-acpi@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Cc: coresight@lists.linaro.org Tested-by: Sudeep Holla sudeep.holla@arm.com # Boot and driver probe only Acked-by: Sudeep Holla sudeep.holla@arm.com # For ACPI related changes Signed-off-by: Anshuman Khandual anshuman.khandual@arm.com
Changes in V3:
- Added commnets for 'drvdata->pclk'
- Used coresight_init_driver()/coresight_remove_driver() helpers instead
- Dropped pm_runtime_put() from replicator_probe()
- Added pm_runtime_put() on success path in dynamic_replicator_probe()
- Added pm_runtime_put() on success/error paths in replicator_platform_probe()
drivers/acpi/arm64/amba.c | 1 - .../coresight/coresight-replicator.c | 81 ++++++++++--------- 2 files changed, 42 insertions(+), 40 deletions(-)
diff --git a/drivers/acpi/arm64/amba.c b/drivers/acpi/arm64/amba.c index 171b5c2c7edd..270f4e3819a2 100644 --- a/drivers/acpi/arm64/amba.c +++ b/drivers/acpi/arm64/amba.c @@ -27,7 +27,6 @@ static const struct acpi_device_id amba_id_list[] = { {"ARMHC503", 0}, /* ARM CoreSight Debug */ {"ARMHC979", 0}, /* ARM CoreSight TPIU */ {"ARMHC97C", 0}, /* ARM CoreSight SoC-400 TMC, SoC-600 ETF/ETB */
- {"ARMHC98D", 0}, /* ARM CoreSight Dynamic Replicator */ {"ARMHC9CA", 0}, /* ARM CoreSight CATU */ {"ARMHC9FF", 0}, /* ARM CoreSight Dynamic Funnel */ {"", 0},
diff --git a/drivers/hwtracing/coresight/coresight-replicator.c b/drivers/hwtracing/coresight/coresight-replicator.c index b6be73034996..125b256cb8db 100644 --- a/drivers/hwtracing/coresight/coresight-replicator.c +++ b/drivers/hwtracing/coresight/coresight-replicator.c @@ -31,6 +31,7 @@ DEFINE_CORESIGHT_DEVLIST(replicator_devs, "replicator");
- @base: memory mapped base address for this component. Also indicates
whether this one is programmable or not.
- @atclk: optional clock for the core parts of the replicator.
- @pclk: APB clock if present, otherwise NULL
- @csdev: component vitals needed by the framework
- @spinlock: serialize enable/disable operations.
- @check_idfilter_val: check if the context is lost upon clock removal.
@@ -38,6 +39,7 @@ DEFINE_CORESIGHT_DEVLIST(replicator_devs, "replicator"); struct replicator_drvdata { void __iomem *base; struct clk *atclk;
- struct clk *pclk; struct coresight_device *csdev; spinlock_t spinlock; bool check_idfilter_val;
@@ -243,6 +245,10 @@ static int replicator_probe(struct device *dev, struct resource *res) return ret; }
- drvdata->pclk = coresight_get_enable_apb_pclk(dev);
- if (IS_ERR(drvdata->pclk))
return -ENODEV;
- /*
- Map the device base for dynamic-replicator, which has been
- validated by AMBA core
@@ -285,7 +291,6 @@ static int replicator_probe(struct device *dev, struct resource *res) } replicator_reset(drvdata);
- pm_runtime_put(dev);
out_disable_clk: if (ret && !IS_ERR_OR_NULL(drvdata->atclk)) @@ -301,29 +306,31 @@ static int replicator_remove(struct device *dev) return 0; } -static int static_replicator_probe(struct platform_device *pdev) +static int replicator_platform_probe(struct platform_device *pdev) {
- struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0); int ret;
pm_runtime_get_noresume(&pdev->dev); pm_runtime_set_active(&pdev->dev); pm_runtime_enable(&pdev->dev);
- /* Static replicators do not have programming base */
- ret = replicator_probe(&pdev->dev, NULL);
- if (ret) {
pm_runtime_put_noidle(&pdev->dev);
pm_runtime_disable(&pdev->dev);
- }
- ret = replicator_probe(&pdev->dev, res);
- pm_runtime_put(&pdev->dev);
I believe pm_runtime_disable() would still be needed on the error path. Otherwise pm_runtime_enable() will remain unbalanced on this error path when the replicator module could not be loaded.
--- a/drivers/hwtracing/coresight/coresight-replicator.c +++ b/drivers/hwtracing/coresight/coresight-replicator.c @@ -317,6 +317,8 @@ static int replicator_platform_probe(struct platform_device *pdev) ret = replicator_probe(&pdev->dev, res); pm_runtime_put(&pdev->dev);
if (ret)
pm_runtime_disable(&pdev->dev);
return ret; }
Similar constructs in this error path are also required in all other drivers (except cpu debug) as well.
Would that not need to be done as a fixes commit first with more detail about the issue if that's true? Maybe simulate the error and paste any error logs. For example etm4 already has this:
There are existing inconsistencies e.g between etm4 and replicator regarding whether pm_runtime_disable() is called or not. So the idea here was to get all remaining devices in line with replicator and debug devices method.
I don't have continuous access to an ACPI based coresight platform, creating some challenges - although still trying to get access to such a system. But wondering - it might be possible to simulate these success and error paths, without having real ACPI based coresight platform devices.
pm_runtime_get_noresume(&pdev->dev); pm_runtime_set_active(&pdev->dev); pm_runtime_enable(&pdev->dev);
ret = etm4_probe(&pdev->dev);
pm_runtime_put(&pdev->dev);
I'm wondering if the disable is already covered by the platform code if the probe fails so no change is required?
AFAICT pm_runtime_enable()/pm_runtime_disable() goes in a pair for them to remain balanced, there is a increasing/decreasing counter to ensure such a balance is established and so without a corresponding pm_runtime_disable() above etm4 path looks problematic. I guess this might just need fixing, as a pre-requisite.
if (drv->probe) { ret = drv->probe(dev); if (ret) dev_pm_domain_detach(_dev, true); }