linux-kernel - [PATCH] mailbox: sun6i-msgbox: Remove unneeded FIFO status check

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Date:   Sat, 15 Feb 2020 00:19:53 -0600
From:   Samuel Holland <samuel@...lland.org>
To:     Maxime Ripard <mripard@...nel.org>, Chen-Yu Tsai <wens@...e.org>,
        Jassi Brar <jassisinghbrar@...il.com>,
        Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Philipp Zabel <p.zabel@...gutronix.de>,
        Ondrej Jirman <megous@...ous.com>,
        Vasily Khoruzhick <anarsoul@...il.com>
Cc:     devicetree@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org, linux-sunxi@...glegroups.com,
        Samuel Holland <samuel@...lland.org>
Subject: [PATCH] mailbox: sun6i-msgbox: Remove unneeded FIFO status check

A transmit FIFO can never be full, because the mailbox framework
waits until mbox->ops->last_tx_done() succeeds before sending the next
message. sun6i_msgbox_last_tx_done() ensures that the FIFO is empty.

Since the extra check here is unnecessary, remove it.

Signed-off-by: Samuel Holland <samuel@...lland.org>
---
 drivers/mailbox/sun6i-msgbox.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/mailbox/sun6i-msgbox.c b/drivers/mailbox/sun6i-msgbox.c
index 15d6fd522dc5..ccecf2e5941d 100644
--- a/drivers/mailbox/sun6i-msgbox.c
+++ b/drivers/mailbox/sun6i-msgbox.c
@@ -106,12 +106,6 @@ static int sun6i_msgbox_send_data(struct mbox_chan *chan, void *data)
 	if (WARN_ON_ONCE(!(readl(mbox->regs + CTRL_REG(n)) & CTRL_TX(n))))
 		return 0;
 
-	/* We cannot post a new message if the FIFO is full. */
-	if (readl(mbox->regs + FIFO_STAT_REG(n)) & FIFO_STAT_MASK) {
-		mbox_dbg(mbox, "Channel %d busy sending 0x%08x\n", n, msg);
-		return -EBUSY;
-	}
-
 	writel(msg, mbox->regs + MSG_DATA_REG(n));
 	mbox_dbg(mbox, "Channel %d sent 0x%08x\n", n, msg);
 
-- 
2.24.1