This is a note to let you know that I've just added the patch titled
i2c: hisi: Avoid redundant interrupts
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
i2c-hisi-avoid-redundant-interrupts.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 9c51cf3f0bdaf883966259bc4e1e8f55c03c6a6a
Author: Yicong Yang <yangyicong@xxxxxxxxxxxxx>
Date: Mon Mar 13 15:45:51 2023 +0800
i2c: hisi: Avoid redundant interrupts
[ Upstream commit cc9812a3096d1986caca9a23bee99effc45c08df ]
After issuing all the messages we can disable the TX_EMPTY interrupts
to avoid handling redundant interrupts. For doing a sinlge bus
detection (i2cdetect -y -r 0) we can reduce ~97% interrupts (before
~12000 after ~400).
Signed-off-by: Sheng Feng <fengsheng5@xxxxxxxxxx>
Signed-off-by: Yicong Yang <yangyicong@xxxxxxxxxxxxx>
Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/i2c/busses/i2c-hisi.c b/drivers/i2c/busses/i2c-hisi.c
index d30071f299879..8a61bee745a16 100644
--- a/drivers/i2c/busses/i2c-hisi.c
+++ b/drivers/i2c/busses/i2c-hisi.c
@@ -314,6 +314,13 @@ static void hisi_i2c_xfer_msg(struct hisi_i2c_controller *ctlr)
max_write == 0)
break;
}
+
+ /*
+ * Disable the TX_EMPTY interrupt after finishing all the messages to
+ * avoid overwhelming the CPU.
+ */
+ if (ctlr->msg_tx_idx == ctlr->msg_num)
+ hisi_i2c_disable_int(ctlr, HISI_I2C_INT_TX_EMPTY);
}
static irqreturn_t hisi_i2c_irq(int irq, void *context)
