Re: [PATCH 2/3] remoteproc: k3-r5: Acquire mailbox handle during probe
From: Beleswar Prasad Padhi
Date: Tue Jun 04 2024 - 01:24:19 EST
Hi Andrew,
On 30/05/24 19:46, Andrew Davis wrote:
On 5/30/24 4:07 AM, Beleswar Padhi wrote:
Acquire the mailbox handle during device probe and do not release handle
in stop/detach routine or error paths. This removes the redundant
requests for mbox handle later during rproc start/attach. This also
allows to defer remoteproc driver's probe if mailbox is not probed yet.
Signed-off-by: Beleswar Padhi <b-padhi@xxxxxx>
---
drivers/remoteproc/ti_k3_r5_remoteproc.c | 66 ++++++++----------------
1 file changed, 21 insertions(+), 45 deletions(-)
diff --git a/drivers/remoteproc/ti_k3_r5_remoteproc.c
b/drivers/remoteproc/ti_k3_r5_remoteproc.c
index 26362a509ae3..157e8fd57665 100644
--- a/drivers/remoteproc/ti_k3_r5_remoteproc.c
+++ b/drivers/remoteproc/ti_k3_r5_remoteproc.c
@@ -391,6 +391,7 @@ static int k3_r5_rproc_request_mbox(struct rproc
*rproc)
struct mbox_client *client = &kproc->client;
struct device *dev = kproc->dev;
int ret;
+ long err;
client->dev = dev;
client->tx_done = NULL;
@@ -400,10 +401,9 @@ static int k3_r5_rproc_request_mbox(struct rproc
*rproc)
kproc->mbox = mbox_request_channel(client, 0);
if (IS_ERR(kproc->mbox)) {
- ret = -EBUSY;
- dev_err(dev, "mbox_request_channel failed: %ld\n",
- PTR_ERR(kproc->mbox));
- return ret;
+ err = PTR_ERR(kproc->mbox);
+ dev_err(dev, "mbox_request_channel failed: %ld\n", err);
+ return (err == -EPROBE_DEFER) ? -EPROBE_DEFER : -EBUSY;
Why turn all other errors into EBUSY? If you just return the error
as-is you
can simply make these 3 lines just:
return dev_err_probe(dev, PTR_ERR(kproc->mbox), "mbox_request_channel
failed\n");
}
/*
@@ -552,10 +552,6 @@ static int k3_r5_rproc_start(struct rproc *rproc)
u32 boot_addr;
int ret;
- ret = k3_r5_rproc_request_mbox(rproc);
- if (ret)
- return ret;
-
boot_addr = rproc->bootaddr;
/* TODO: add boot_addr sanity checking */
dev_dbg(dev, "booting R5F core using boot addr = 0x%x\n",
boot_addr);
@@ -564,7 +560,7 @@ static int k3_r5_rproc_start(struct rproc *rproc)
core = kproc->core;
ret = ti_sci_proc_set_config(core->tsp, boot_addr, 0, 0);
if (ret)
- goto put_mbox;
+ goto out;
The label "out" doesn't do anything, just directly `return ret;` here and
in the other cases below.
/* unhalt/run all applicable cores */
if (cluster->mode == CLUSTER_MODE_LOCKSTEP) {
@@ -581,12 +577,12 @@ static int k3_r5_rproc_start(struct rproc *rproc)
dev_err(dev, "%s: can not start core 1 before core 0\n",
__func__);
ret = -EPERM;
- goto put_mbox;
+ goto out;
}
ret = k3_r5_core_run(core);
if (ret)
- goto put_mbox;
+ goto out;
}
return 0;
@@ -596,8 +592,7 @@ static int k3_r5_rproc_start(struct rproc *rproc)
if (k3_r5_core_halt(core))
dev_warn(core->dev, "core halt back failed\n");
}
-put_mbox:
- mbox_free_channel(kproc->mbox);
+out:
return ret;
}
@@ -658,8 +653,6 @@ static int k3_r5_rproc_stop(struct rproc *rproc)
goto out;
}
- mbox_free_channel(kproc->mbox);
-
return 0;
unroll_core_halt:
@@ -674,42 +667,21 @@ static int k3_r5_rproc_stop(struct rproc *rproc)
/*
* Attach to a running R5F remote processor (IPC-only mode)
*
- * The R5F attach callback only needs to request the mailbox, the
remote
- * processor is already booted, so there is no need to issue any TI-SCI
- * commands to boot the R5F cores in IPC-only mode. This callback is
invoked
- * only in IPC-only mode.
+ * The R5F attach callback is a NOP. The remote processor is already
booted, and
+ * all required resources have been acquired during probe routine,
so there is
+ * no need to issue any TI-SCI commands to boot the R5F cores in
IPC-only mode.
+ * This callback is invoked only in IPC-only mode and exists for
sanity sake.
*/
-static int k3_r5_rproc_attach(struct rproc *rproc)
-{
- struct k3_r5_rproc *kproc = rproc->priv;
- struct device *dev = kproc->dev;
- int ret;
-
- ret = k3_r5_rproc_request_mbox(rproc);
- if (ret)
- return ret;
-
- dev_info(dev, "R5F core initialized in IPC-only mode\n");
- return 0;
-}
+static int k3_r5_rproc_attach(struct rproc *rproc) { return 0; }
/*
* Detach from a running R5F remote processor (IPC-only mode)
*
- * The R5F detach callback performs the opposite operation to attach
callback
- * and only needs to release the mailbox, the R5F cores are not
stopped and
- * will be left in booted state in IPC-only mode. This callback is
invoked
- * only in IPC-only mode.
+ * The R5F detach callback is a NOP. The R5F cores are not stopped
and will be
+ * left in booted state in IPC-only mode. This callback is invoked
only in
+ * IPC-only mode and exists for sanity sake.
*/
-static int k3_r5_rproc_detach(struct rproc *rproc)
-{
- struct k3_r5_rproc *kproc = rproc->priv;
- struct device *dev = kproc->dev;
-
- mbox_free_channel(kproc->mbox);
- dev_info(dev, "R5F core deinitialized in IPC-only mode\n");
- return 0;
-}
+static int k3_r5_rproc_detach(struct rproc *rproc) { return 0; }
Do we still need to disable the mbox channel somehow here to prevent
receiving more messages from the detached core?
/*
* This function implements the .get_loaded_rsc_table() callback
and is used
@@ -1277,6 +1249,10 @@ static int k3_r5_cluster_rproc_init(struct
platform_device *pdev)
kproc->rproc = rproc;
core->rproc = rproc;
+ ret = k3_r5_rproc_request_mbox(rproc);
Now that we get the channel here in init you'll want to add a matching
mbox_free_channel() call to k3_r5_cluster_rproc_exit().
Andrew
Thanks for the review! I have sent out v2 addressing these comments:
https://lore.kernel.org/all/20240604051722.3608750-1-b-padhi@xxxxxx/
+ if (ret)
+ return ret;
+
ret = k3_r5_rproc_configure_mode(kproc);
if (ret < 0)
goto err_config;