6.6-stable review patch. If anyone has any objections, please let me know.
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From: Pekka Pessi ppessi@nvidia.com
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 ppessi@nvidia.com Signed-off-by: Kartik Rajput kkartik@nvidia.com Acked-by: Thierry Reding treding@nvidia.com Signed-off-by: Jassi Brar jassisinghbrar@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/mailbox/tegra-hsp.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
--- a/drivers/mailbox/tegra-hsp.c +++ b/drivers/mailbox/tegra-hsp.c @@ -388,7 +388,6 @@ static void tegra_hsp_sm_recv32(struct t 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 t * 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 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_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 = {