kernel/linux.git/drivers/mailbox/mailbox.c, branch v4.9.331

mailbox: handle failed named mailbox channel request

2019-08-04T07:33:41+00:00

[ Upstream commit 25777e5784a7b417967460d4fcf9660d05a0c320 ] Previously, if mbox_request_channel_byname was used with a name which did not exist in the "mbox-names" property of a mailbox client, the mailbox corresponding to the last entry in the "mbox-names" list would be incorrectly selected. With this patch, -EINVAL is returned if the named mailbox is not found. Signed-off-by: Morten Borup Petersen Signed-off-by: Jassi Brar Signed-off-by: Sasha Levin

mailbox: handle empty message in tx_tick

2017-08-07T01:59:42+00:00

commit cb710ab1d8a23f68ff8f45aedf3e552bb90e70de upstream. 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 Signed-off-by: Amit Pundir Signed-off-by: Greg Kroah-Hartman

mailbox: skip complete wait event if timer expired

2017-08-07T01:59:42+00:00

commit cc6eeaa3029a6dbcb4ad41b1f92876483bd88965 upstream. 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 Signed-off-by: Amit Pundir Signed-off-by: Greg Kroah-Hartman

mailbox: always wait in mbox_send_message for blocking Tx mode

2017-08-07T01:59:42+00:00

commit c61b781ee084e69855477d23dd33e7e6caad652c upstream. 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 Signed-off-by: Amit Pundir Signed-off-by: Greg Kroah-Hartman

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

Mailbox: Add support for Platform Communication Channel

2014-11-27T07:21:09+00:00

ACPI 5.0+ spec defines a generic mode of communication between the OS and a platform such as the BMC. This medium (PCC) is typically used by CPPC (ACPI CPU Performance management), RAS (ACPI reliability protocol) and MPST (ACPI Memory power states). This patch adds PCC support as a Mailbox Controller. As of ACPI v5.1 there is no provision for clients to lookup mailbox controllers in a way that Linux expects. e.g. in DT the clients can list the mailboxes they can associate with in the DT binding and then provide a unique index to lookup a channel within a mailbox. Since the ACPI spec doesn't have anything similar, we introduce a mailbox controller specific API so that when the client calls it, we know to lookup in the context of a specific controller. This also helps in keeping a consistent interface across DT and ACPI for such drivers. This patch implements basic PCC support using the ACPI v5.1 structures. IRQ mode support will be provided as follow up patches. Signed-off-by: Ashwin Chaugule Reviewed-by: Mark Brown Reviewed-by: Arnd Bergmann Signed-off-by: Jassi Brar