linux.git/drivers/mailbox/mailbox.c, branch v4.12

mailbox: handle empty message in tx_tick

2017-04-27T10:50:04+00:00

We already check if the message is empty before calling the client
tx_done callback. Calling completion on a wait event is also invalid
if the message is empty.

This patch moves the existing empty message check earlier.

Fixes: 2b6d83e2b8b7 ("mailbox: Introduce framework for mailbox")
Signed-off-by: Sudeep Holla 
Signed-off-by: Jassi Brar

mailbox: skip complete wait event if timer expired

2017-04-27T10:50:04+00:00

If a wait_for_completion_timeout() call returns due to a timeout,
complete() can get called after returning from the wait which is
incorrect and can cause subsequent transmissions on a channel to fail.
Since the wait_for_completion_timeout() sees the completion variable
is non-zero caused by the erroneous/spurious complete() call, and
it immediately returns without waiting for the time as expected by the
client.

This patch fixes the issue by skipping complete() call for the timer
expiry.

Fixes: 2b6d83e2b8b7 ("mailbox: Introduce framework for mailbox")
Reported-by: Alexey Klimov 
Signed-off-by: Sudeep Holla 
Signed-off-by: Jassi Brar

mailbox: always wait in mbox_send_message for blocking Tx mode

2017-04-27T10:50:04+00:00

There exists a race when msg_submit return immediately as there was an
active request being processed which may have completed just before it's
checked again in mbox_send_message. This will result in return to the
caller without waiting in mbox_send_message even when it's blocking Tx.

This patch fixes the issue by waiting for the completion always if Tx
is in blocking mode.

Fixes: 2b6d83e2b8b7 ("mailbox: Introduce framework for mailbox")
Reported-by: Alexey Klimov 
Signed-off-by: Sudeep Holla 
Reviewed-by: Alexey Klimov 
Signed-off-by: Jassi Brar

mailbox: check ->last_tx_done for NULL in case of timer-based polling

2017-03-28T18:22:02+00:00

It is allowed by code to register mailbox controller that sets txdone_poll
flag to request timer-based polling with missed ->last_tx_done() method.
If such thing happens and since presence of last_tx_done() is not checked
it will fail in hrtimer callback function txdone_hrtimer() when first
message will be transmitted.

This patch adds check for this method and logging of error on
registration of mailbox controller if it requested timer-based polling.

Signed-off-by: Alexey Klimov 
Acked-by: Sudeep Holla 
Signed-off-by: Jassi Brar

ktime: Cleanup ktime_set() usage

2016-12-25T16:21:22+00:00

ktime_set(S,N) was required for the timespec storage type and is still
useful for situations where a Seconds and Nanoseconds part of a time value
needs to be converted. For anything where the Seconds argument is 0, this
is pointless and can be replaced with a simple assignment.

Signed-off-by: Thomas Gleixner 
Cc: Peter Zijlstra

mailbox: Stop using ENOSYS for anything other than unimplemented syscalls

2016-04-12T07:58:32+00:00

In accordance with e15f431fe2d5 ("errno.h: Improve ENOSYS's comment") and
91c9afaf97ee ("checkpatch.pl: new instances of ENOSYS are errors") we're
converting from the old meaning of: ENOSYS "Function not implemented" to
a more standard EINVAL.

Reported-by: Seraphin Bonnaffe 
Signed-off-by: Lee Jones 
Signed-off-by: Jassi Brar

mailbox: switch to hrtimer for tx_complete polling

2015-08-10T08:59:27+00:00

The mailbox core uses jiffy based timer to handle polling for the
transmit completion. If the client/protocol have/support notification
of the last packet transmit completion via ACK packet, then we tick the
Tx state machine immediately in the callback. However if the client
doesn't support that mechanism we might end-up waiting for atleast a
jiffy even though the remote is ready to receive the next request.

This patch switches the timer used for that polling from jiffy-based
to hrtimer-based so that we can support polling at much higher time
resolution.

Reported-and-suggested-by: Juri Lelli 
Signed-off-by: Sudeep Holla 
Signed-off-by: Jassi Brar

mailbox: Add ability for clients to request channels by name

2015-06-11T16:49:45+00:00

This patch supplies a new framework API; mbox_request_channel_byname().

It works by supplying the usual client pointer as the first argument and
a string as the second.  The API will search the client's node for a
'mbox-names' property then request a channel in the normal way using the
requested string's index as the expected second 'index' argument.

Signed-off-by: Lee Jones 
Signed-off-by: Jassi Brar

mailbox: Fix up error handling in mbox_request_channel()

2015-05-12T03:48:21+00:00

mbox_request_channel() currently returns EBUSY in the event the controller
is not present or if of_xlate() fails, but in neither case is EBUSY really
appropriate.  Return EPROBE_DEFER if the controller is not yet present
and change of_xlate() to return an ERR_PTR instead of NULL so that the
error can be propagated back to the caller of mbox_request_channel().

Signed-off-by: Benson Leung 
Signed-off-by: Andrew Bresticker 
Acked-by: Suman Anna 
Reviewed-by: Jon Hunter 
Tested-by: Jon Hunter 
Signed-off-by: Jassi Brar

mailbox: check for bit set before polling

2015-02-06T05:28:05+00:00

Before polling we just need to see if the TXDONE_BY_POLL bit
is set in txdone_method. There may be another bit (method)
specified as well, like TXDONE_BY_ACK.

Signed-off-by: Jassi Brar