Re: [PATCH 5/5] mailbox: mtk-cmdq: Add support runtime get and set GCE event

From: AngeloGioacchino Del Regno
Date: Tue Mar 05 2024 - 05:34:29 EST


Il 05/03/24 04:09, Jason-JH Lin (林睿祥) ha scritto:
Hi Angelo,

Thanks for the reviews.

On Mon, 2024-03-04 at 11:06 +0100, AngeloGioacchino Del Regno wrote:
Il 01/03/24 12:11, Jason-JH.Lin ha scritto:
ISP drivers need to get and set GCE event in their runtime contorl
flow.
So add these functions to support get and set GCE by CPU.

Signed-off-by: Jason-JH.Lin <jason-jh.lin@xxxxxxxxxxxx>
Change-Id: I494c34ebc5ec26c82213f2bc03d2033d60652523

Change-Id makes no sense upstream. Please drop.

OK, I'll drop it.


---
drivers/mailbox/mtk-cmdq-mailbox.c | 37
++++++++++++++++++++++++
include/linux/mailbox/mtk-cmdq-mailbox.h | 2 ++
2 files changed, 39 insertions(+)

diff --git a/drivers/mailbox/mtk-cmdq-mailbox.c
b/drivers/mailbox/mtk-cmdq-mailbox.c
index ead2200f39ba..d7c08249c898 100644
--- a/drivers/mailbox/mtk-cmdq-mailbox.c
+++ b/drivers/mailbox/mtk-cmdq-mailbox.c
@@ -25,7 +25,11 @@
#define CMDQ_GCE_NUM_MAX (2)
#define CMDQ_CURR_IRQ_STATUS 0x10
+#define CMDQ_SYNC_TOKEN_ID 0x60
+#define CMDQ_SYNC_TOKEN_VALUE 0x64
+#define CMDQ_TOKEN_ID_MASK GENMASK(9, 0)
#define CMDQ_SYNC_TOKEN_UPDATE 0x68
+#define CMDQ_TOKEN_UPDATE_VALUE BIT(16)
#define CMDQ_THR_SLOT_CYCLES 0x30
#define CMDQ_THR_BASE 0x100
#define CMDQ_THR_SIZE 0x80
@@ -83,6 +87,7 @@ struct cmdq {
struct cmdq_thread *thread;
struct clk_bulk_data clocks[CMDQ_GCE_NUM_MAX];
bool suspended;
+ spinlock_t event_lock; /* lock for gce event */
};
struct gce_plat {
@@ -113,6 +118,38 @@ u8 cmdq_get_shift_pa(struct mbox_chan *chan)
}
EXPORT_SYMBOL(cmdq_get_shift_pa);
+void cmdq_set_event(void *chan, u16 event_id)
+{
+ struct cmdq *cmdq = container_of(((struct mbox_chan *)chan)-
mbox,
+ typeof(*cmdq), mbox);

struct mbox_chan *mbc = chan;
struct cmdq *cmdq = container_of(mbc->mbox, ... etc); (and this fits
in one line)

OK, I'll change it.

+ unsigned long flags;
+
+ spin_lock_irqsave(&cmdq->event_lock, flags);

Why do you need irqsave/irqrestore? I think I know, but please
explain.

Because ISP driver may call cmdq_get_event() first than use
cmdq_set_event() to update the event status in one
mtk_imgsys_setevent() function frequently.

And mtk_imgsys_setevent() will be called in SW multi-thread after cmdq
callback from cmdq_irq_handler, so we use the spin_lock_irqsave to
avoid the race condition.

I was imagining something like that, yes - thank you for explaining.

Cheers,
Angelo