Re: [PATCH v4 3/7] staging: vchiq_core: Factor out bulk transfer for blocking mode
From: Stefan Wahren
Date: Sun Sep 08 2024 - 06:41:29 EST
Hi Umang,
Am 07.09.24 um 20:26 schrieb Umang Jain:
Hi Stefan
On 07/09/24 5:19 pm, Stefan Wahren wrote:
Hi Umang,
Am 06.09.24 um 09:25 schrieb Umang Jain:
Factor out bulk transfer for blocking mode into a separate dedicated
function bulk_xfer_blocking_interruptible(). It is suffixed by
"_interruptible" to denote that it can be interrupted and -EAGAIN
can be returned. It would be up to the users of the function to retry
the call in those cases.
Adjust the calls to vchiq-dev.c ioctl interface and vchiq_arm.c
for blocking bulk transfers.
Signed-off-by: Umang Jain <umang.jain@xxxxxxxxxxxxxxxx>
i applied this series on top of recent linux-next and the vchiq ping
test on Raspberry Pi 3 B Plus (multi_v7_defconfig) crashes or hanges
strangly.
This is really annoying. The behavior is non-deterministic
I tested this repeatedly and I see the hang on my 3rd ping test.
The first 2 ping tests completed successfully.
Here is the output for all 3 tries:
https://paste.debian.net/plain/1328739
I'll take a look and fix it in next version.
I was too imprecise with my information.
Just try "vchiq_test -p" which makes a big difference in reproducibility.
Best regards
I bisected the issue to this patch, but it's possible the root cause
might be introduced before.
But i'm pretty sure that the series introduced the regression.
Sorry, i don't have the time analyse this issue deeper.
Best regards
---
.../interface/vchiq_arm/vchiq_arm.c | 5 +--
.../interface/vchiq_arm/vchiq_core.c | 42
++++++++++++++++---
.../interface/vchiq_arm/vchiq_core.h | 5 +++
.../interface/vchiq_arm/vchiq_dev.c | 6 +++
4 files changed, 49 insertions(+), 9 deletions(-)
diff --git
a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
index c4d97dbf6ba8..688c9b1be868 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
@@ -968,9 +968,8 @@ vchiq_blocking_bulk_transfer(struct
vchiq_instance *instance, unsigned int handl
return -ENOMEM;
}
- ret = vchiq_bulk_transfer(instance, handle, data, NULL, size,
- &waiter->bulk_waiter,
- VCHIQ_BULK_MODE_BLOCKING, dir);
+ ret = vchiq_bulk_xfer_blocking_interruptible(instance, handle,
data, NULL, size,
+ &waiter->bulk_waiter, dir);
if ((ret != -EAGAIN) || fatal_signal_pending(current) ||
!waiter->bulk_waiter.bulk) {
struct vchiq_bulk *bulk = waiter->bulk_waiter.bulk;
diff --git
a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
index f36044bab194..43f951fa4b89 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
@@ -2985,6 +2985,42 @@ vchiq_remove_service(struct vchiq_instance
*instance, unsigned int handle)
return status;
}
+int
+vchiq_bulk_xfer_blocking_interruptible(struct vchiq_instance
*instance, unsigned int handle,
+ void *offset, void __user *uoffset, int size,
+ void __user *userdata, enum vchiq_bulk_dir dir)
+{
+ struct vchiq_service *service =
find_service_by_handle(instance, handle);
+ struct bulk_waiter *bulk_waiter;
+ enum vchiq_bulk_mode mode = VCHIQ_BULK_MODE_BLOCKING;
+ int status = -EINVAL;
+
+ if (!service)
+ return -EINVAL;
+
+ if (service->srvstate != VCHIQ_SRVSTATE_OPEN)
+ goto error_exit;
+
+ if (!offset && !uoffset)
+ goto error_exit;
+
+ if (vchiq_check_service(service))
+ goto error_exit;
+
+ bulk_waiter = userdata;
+ init_completion(&bulk_waiter->event);
+ bulk_waiter->actual = 0;
+ bulk_waiter->bulk = NULL;
+
+ status = vchiq_bulk_xfer_queue_msg_interruptible(service,
offset, uoffset, size,
+ userdata, mode, dir);
+
+error_exit:
+ vchiq_service_put(service);
+
+ return status;
+}
+
/*
* This function may be called by kernel threads or user threads.
* User threads may receive -EAGAIN to indicate that a signal has
been
@@ -3018,12 +3054,6 @@ int vchiq_bulk_transfer(struct vchiq_instance
*instance, unsigned int handle,
case VCHIQ_BULK_MODE_NOCALLBACK:
case VCHIQ_BULK_MODE_CALLBACK:
break;
- case VCHIQ_BULK_MODE_BLOCKING:
- bulk_waiter = userdata;
- init_completion(&bulk_waiter->event);
- bulk_waiter->actual = 0;
- bulk_waiter->bulk = NULL;
- break;
default:
goto error_exit;
}
diff --git
a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h
b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h
index 985d9ea3a06a..2dd89101c1c6 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h
@@ -474,6 +474,11 @@ extern int
vchiq_bulk_xfer_waiting_interruptible(struct vchiq_instance
*instance,
unsigned int handle, struct bulk_waiter
*userdata);
+extern int
+vchiq_bulk_xfer_blocking_interruptible(struct vchiq_instance
*instance, unsigned int handle,
+ void *offset, void __user *uoffset, int size,
+ void __user *userdata, enum vchiq_bulk_dir
dir);
+
extern int
vchiq_bulk_transfer(struct vchiq_instance *instance, unsigned int
handle, void *offset,
void __user *uoffset, int size, void *userdata, enum
vchiq_bulk_mode mode,
diff --git
a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_dev.c
b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_dev.c
index 550838d2863b..830633f2326b 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_dev.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_dev.c
@@ -304,6 +304,12 @@ static int vchiq_irq_queue_bulk_tx_rx(struct
vchiq_instance *instance,
}
userdata = &waiter->bulk_waiter;
+
+ status = vchiq_bulk_xfer_blocking_interruptible(instance,
args->handle,
+ NULL, args->data, args->size,
+ userdata, dir);
+
+ goto bulk_transfer_handled;
} else if (args->mode == VCHIQ_BULK_MODE_WAITING) {
mutex_lock(&instance->bulk_waiter_list_mutex);
list_for_each_entry(iter, &instance->bulk_waiter_list,