From 98874c14017510c2602bbb437f7d81a269ac84ab Mon Sep 17 00:00:00 2001 From: Pekka Pessi Date: Mon, 2 Dec 2024 15:35:59 +0530 Subject: [PATCH] mailbox: tegra-hsp: Clear mailbox before using message BugLink: https://bugs.launchpad.net/bugs/2114239 commit 0b7f8328f988178b55ee11d772a6e1238c04d29d upstream. The Tegra RCE (Camera) driver expects the mailbox to be empty before processing the IVC messages. On RT kernel, the threads processing the IVC messages (which are invoked after `mbox_chan_received_data()` is called) may be on a different CPU or running with a higher priority than the HSP interrupt handler thread. This can cause it to act on the message before the mailbox gets cleared in the HSP interrupt handler resulting in a loss of IVC notification. Fix this by clearing the mailbox data register before calling `mbox_chan_received_data()`. Fixes: 8f585d14030d ("mailbox: tegra-hsp: Add tegra_hsp_sm_ops") Fixes: 74c20dd0f892 ("mailbox: tegra-hsp: Add 128-bit shared mailbox support") Cc: stable@vger.kernel.org Signed-off-by: Pekka Pessi Signed-off-by: Kartik Rajput Acked-by: Thierry Reding Signed-off-by: Jassi Brar Signed-off-by: Greg Kroah-Hartman Signed-off-by: Noah Wager Signed-off-by: Mehmet Basaran --- drivers/mailbox/tegra-hsp.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/mailbox/tegra-hsp.c b/drivers/mailbox/tegra-hsp.c index 19ef56cbcfd3..46c921000a34 100644 --- a/drivers/mailbox/tegra-hsp.c +++ b/drivers/mailbox/tegra-hsp.c @@ -388,7 +388,6 @@ static void tegra_hsp_sm_recv32(struct tegra_hsp_channel *channel) value = tegra_hsp_channel_readl(channel, HSP_SM_SHRD_MBOX); value &= ~HSP_SM_SHRD_MBOX_FULL; msg = (void *)(unsigned long)value; - mbox_chan_received_data(channel->chan, msg); /* * Need to clear all bits here since some producers, such as TCU, depend @@ -398,6 +397,8 @@ static void tegra_hsp_sm_recv32(struct tegra_hsp_channel *channel) * explicitly, so we have to make sure we cover all possible cases. */ tegra_hsp_channel_writel(channel, 0x0, HSP_SM_SHRD_MBOX); + + mbox_chan_received_data(channel->chan, msg); } static const struct tegra_hsp_sm_ops tegra_hsp_sm_32bit_ops = { @@ -433,7 +434,6 @@ static void tegra_hsp_sm_recv128(struct tegra_hsp_channel *channel) value[3] = tegra_hsp_channel_readl(channel, HSP_SHRD_MBOX_TYPE1_DATA3); msg = (void *)(unsigned long)value; - mbox_chan_received_data(channel->chan, msg); /* * Clear data registers and tag. @@ -443,6 +443,8 @@ static void tegra_hsp_sm_recv128(struct tegra_hsp_channel *channel) tegra_hsp_channel_writel(channel, 0x0, HSP_SHRD_MBOX_TYPE1_DATA2); tegra_hsp_channel_writel(channel, 0x0, HSP_SHRD_MBOX_TYPE1_DATA3); tegra_hsp_channel_writel(channel, 0x0, HSP_SHRD_MBOX_TYPE1_TAG); + + mbox_chan_received_data(channel->chan, msg); } static const struct tegra_hsp_sm_ops tegra_hsp_sm_128bit_ops = {