[PATCH 3/3] i2c: thunderx: Use polling with delay in HS mode

[Paul Cercueil <paul.cercueil@bootlin.com>]

From: Tanmay Jagdale <tanmay@marvell.com>

High I2C transaction latencies exceeding 1 second were intermittently
observed while operating in HS mode. These delays caused DTLS handshakes
between the main processor and firmware processors to time out,
resulting in increased startup time.

Replace the existing wait mechanism with delayed polling in HS mode to
improve transfer responsiveness and avoid prolonged latency spikes.

Signed-off-by: Tanmay Jagdale <tanmay@marvell.com>
Co-developed-by: Paul Cercueil <paul.cercueil@bootlin.com>
Signed-off-by: Paul Cercueil <paul.cercueil@bootlin.com>
---
 drivers/i2c/busses/i2c-octeon-core.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/i2c/busses/i2c-octeon-core.c b/drivers/i2c/busses/i2c-octeon-core.c
index 9f72ec1feaa0..4c05d2d00cbe 100644
--- a/drivers/i2c/busses/i2c-octeon-core.c
+++ b/drivers/i2c/busses/i2c-octeon-core.c
@@ -15,6 +15,7 @@
 #include <linux/delay.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
+#include <linux/iopoll.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/pci.h>
@@ -65,6 +66,9 @@ static int octeon_i2c_wait(struct octeon_i2c *i2c)
 		return octeon_i2c_test_iflg(i2c) ? 0 : -ETIMEDOUT;
 	}
 
+	if (!IS_LS_FREQ(i2c->twsi_freq))
+		return poll_timeout_us_atomic(, octeon_i2c_test_iflg(i2c), 1, 1000, false);
+
 	i2c->int_enable(i2c);
 	time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_iflg(i2c),
 				       i2c->adap.timeout);
-- 
2.47.3