kernel/drivers/mailbox/mailbox.c, branch linux-5.1.y

mailbox: Export mbox_flush()

2019-02-18T16:39:17Z

The mbox_flush() function can be used by drivers that are built as modules, so the function needs to be exported. Reported-by: Mark Brown Signed-off-by: Thierry Reding Signed-off-by: Jassi Brar

mailbox: Allow multiple controllers per device

2018-12-22T04:31:26Z

Look through the whole controller list when mapping device tree phandles to controllers instead of stopping at the first one. Each controller is intended to only contain one kind of mailbox, but some devices (like Tegra HSP) implement multiple kinds and use the same device tree node for all of them. As such, we need to allow multiple mbox_controllers per device tree node. Signed-off-by: Mikko Perttunen Signed-off-by: Jassi Brar

mailbox: Support blocking transfers in atomic context

2018-12-22T04:31:26Z

The mailbox framework supports blocking transfers via completions for clients that can sleep. In order to support blocking transfers in cases where the transmission is not permitted to sleep, add a new ->flush() callback that controller drivers can implement to busy loop until the transmission has been completed. A new mbox_flush() function can be called by mailbox consumers in atomic context to make sure a transfer has completed. Signed-off-by: Thierry Reding Signed-off-by: Jassi Brar

mailbox: Add device-managed registration functions

2018-12-21T22:49:25Z

Add device-managed equivalents of the mbox_controller_register() and mbox_controller_unregister() functions that can be used to have the devres infrastructure automatically unregister mailbox controllers on driver probe failure or driver removal. This can help remove a lot of boiler plate code from drivers. Reviewed-by: Bjorn Andersson Reviewed-by: Sudeep Holla Signed-off-by: Thierry Reding Signed-off-by: Jassi Brar

mailbox: reset txdone_method TXDONE_BY_POLL if client knows_txdone

2017-11-14T14:51:28Z

Currently the mailbox framework sets txdone_method to TXDONE_BY_POLL if the controller sets txdone_by_poll. However some clients can have a mechanism to do TXDONE_BY_ACK which they can specify by knows_txdone. However, we endup setting both TXDONE_BY_POLL and TXDONE_BY_ACK in that case. In such scenario, we may end up with below warnings as the tx ticker is run both by mailbox framework and the client. WARNING: CPU: 1 PID: 0 at kernel/time/hrtimer.c:805 hrtimer_forward+0x88/0xd8 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.12.0-rc5 #242 Hardware name: ARM LTD ARM Juno Development Platform task: ffff8009768ca700 task.stack: ffff8009768f8000 PC is at hrtimer_forward+0x88/0xd8 LR is at txdone_hrtimer+0xd4/0xf8 Call trace: hrtimer_forward+0x88/0xd8 __hrtimer_run_queues+0xe4/0x158 hrtimer_interrupt+0xa4/0x220 arch_timer_handler_phys+0x30/0x40 handle_percpu_devid_irq+0x78/0x130 generic_handle_irq+0x24/0x38 __handle_domain_irq+0x5c/0xb8 gic_handle_irq+0x54/0xa8 This patch fixes the issue by resetting TXDONE_BY_POLL if client has set knows_txdone. Cc: Alexey Klimov Signed-off-by: Sudeep Holla Signed-off-by: Jassi Brar

mailbox: Make startup and shutdown ops optional

2017-06-14T12:17:09Z

Some mailbox hardware doesn't have to perform any additional operations on startup of shutdown, so make these optional. Signed-off-by: Bjorn Andersson Signed-off-by: Jassi Brar

mailbox: handle empty message in tx_tick

2017-04-27T10:50:04Z

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

2017-04-27T10:50:04Z

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

2017-04-27T10:50:04Z

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

2017-03-28T18:22:02Z

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