From: Raag Jadav <raagjadav@gmail.com>
To: linux-i2c@vger.kernel.org
Cc: alexandre.belloni@bootlin.com, linux-kernel@vger.kernel.org,
ludovic.desroches@microchip.com, Raag Jadav <raagjadav@gmail.com>,
linux-arm-kernel@lists.infradead.org
Subject: [PATCH] i2c: at91: handle TXRDY interrupt spam
Date: Tue, 23 Apr 2019 13:06:48 +0530 [thread overview]
Message-ID: <1556005008-6318-1-git-send-email-raagjadav@gmail.com> (raw)
Performing i2c write operation while SDA or SCL line is held
or grounded by slave device, we go into infinite at91_twi_write_next_byte
loop with TXRDY interrupt spam.
Signed-off-by: Raag Jadav <raagjadav@gmail.com>
---
drivers/i2c/busses/i2c-at91.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c
index 3f3e8b3..b2f5fdb 100644
--- a/drivers/i2c/busses/i2c-at91.c
+++ b/drivers/i2c/busses/i2c-at91.c
@@ -72,6 +72,7 @@
#define AT91_TWI_TXCOMP BIT(0) /* Transmission Complete */
#define AT91_TWI_RXRDY BIT(1) /* Receive Holding Register Ready */
#define AT91_TWI_TXRDY BIT(2) /* Transmit Holding Register Ready */
+#define AT91_TWI_SVREAD BIT(3) /* Slave Read */
#define AT91_TWI_OVRE BIT(6) /* Overrun Error */
#define AT91_TWI_UNRE BIT(7) /* Underrun Error */
#define AT91_TWI_NACK BIT(8) /* Not Acknowledged */
@@ -571,7 +572,10 @@ static irqreturn_t atmel_twi_interrupt(int irq, void *dev_id)
at91_disable_twi_interrupts(dev);
complete(&dev->cmd_complete);
} else if (irqstatus & AT91_TWI_TXRDY) {
- at91_twi_write_next_byte(dev);
+ if ((status & AT91_TWI_SVREAD) && (dev->buf_len == 0))
+ at91_twi_write(dev, AT91_TWI_IDR, AT91_TWI_TXRDY);
+ else
+ at91_twi_write_next_byte(dev);
}
/* catch error flags */
--
2.7.4
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next reply other threads:[~2019-04-23 7:38 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-23 7:36 Raag Jadav [this message]
2019-04-29 9:00 ` [PATCH] i2c: at91: handle TXRDY interrupt spam Ludovic Desroches
2019-04-29 22:33 ` Raag Jadav
2019-05-02 14:01 ` Ludovic Desroches
2019-05-03 23:58 ` Raag Jadav
2019-05-06 8:19 ` Eugen.Hristev
2019-05-06 16:02 ` Raag Jadav
2019-05-14 8:52 ` Ludovic Desroches
2019-05-14 8:42 ` Ludovic Desroches
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