Re: [PATCH v7 3/5] remoteproc: Add support for runtime PM

From: Paul Cercueil
Date: Fri May 22 2020 - 13:11:29 EST


Hi Suman,

Le ven. 22 mai 2020 à 11:47, Suman Anna <s-anna@xxxxxx> a écrit :
Hi Paul,

On 5/15/20 5:43 AM, Paul Cercueil wrote:
Call pm_runtime_get_sync() before the firmware is loaded, and
pm_runtime_put() after the remote processor has been stopped.

Even though the remoteproc device has no PM callbacks, this allows the
parent device's PM callbacks to be properly called.

I see this patch staged now for 5.8, and the latest -next branch has broken the pm-runtime autosuspend feature we have in the OMAP remoteproc driver. See commit 5f31b232c674 ("remoteproc/omap: Add support for runtime auto-suspend/resume").

What was the original purpose of this patch, because there can be differing backends across different SoCs.

Did you try pm_suspend_ignore_children()? It looks like it was made for your use-case.

Cheers,
-Paul


regards
Suman


Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
---

Notes:
v2-v4: No change
v5: Move calls to prepare/unprepare to rproc_fw_boot/rproc_shutdown
v6: Instead of prepare/unprepare callbacks, use PM runtime callbacks
v7: Check return value of pm_runtime_get_sync()

drivers/remoteproc/remoteproc_core.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index a7f96bc98406..e33d1ef27981 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -29,6 +29,7 @@
#include <linux/devcoredump.h>
#include <linux/rculist.h>
#include <linux/remoteproc.h>
+#include <linux/pm_runtime.h>
#include <linux/iommu.h>
#include <linux/idr.h>
#include <linux/elf.h>
@@ -1382,6 +1383,12 @@ static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
if (ret)
return ret;
+ ret = pm_runtime_get_sync(dev);
+ if (ret < 0) {
+ dev_err(dev, "pm_runtime_get_sync failed: %d\n", ret);
+ return ret;
+ }
+
dev_info(dev, "Booting fw image %s, size %zd\n", name, fw->size);
 /*
@@ -1391,7 +1398,7 @@ static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
ret = rproc_enable_iommu(rproc);
if (ret) {
dev_err(dev, "can't enable iommu: %d\n", ret);
- return ret;
+ goto put_pm_runtime;
}
 rproc->bootaddr = rproc_get_boot_addr(rproc, fw);
@@ -1435,6 +1442,8 @@ static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
rproc->table_ptr = NULL;
disable_iommu:
rproc_disable_iommu(rproc);
+put_pm_runtime:
+ pm_runtime_put(dev);
return ret;
}
@@ -1840,6 +1849,8 @@ void rproc_shutdown(struct rproc *rproc)
 rproc_disable_iommu(rproc);
+ pm_runtime_put(dev);
+
/* Free the copy of the resource table */
kfree(rproc->cached_table);
rproc->cached_table = NULL;
@@ -2118,6 +2129,9 @@ struct rproc *rproc_alloc(struct device *dev, const char *name,
 rproc->state = RPROC_OFFLINE;
+ pm_runtime_no_callbacks(&rproc->dev);
+ pm_runtime_enable(&rproc->dev);
+
return rproc;
}
EXPORT_SYMBOL(rproc_alloc);
@@ -2133,6 +2147,7 @@ EXPORT_SYMBOL(rproc_alloc);
*/
void rproc_free(struct rproc *rproc)
{
+ pm_runtime_disable(&rproc->dev);
put_device(&rproc->dev);
}
EXPORT_SYMBOL(rproc_free);