From: Marek Vasut <marex@denx.de>
To: linux-i2c@vger.kernel.org
Cc: Marek Vasut <marex@denx.de>,
Michal Simek <michal.simek@xilinx.com>,
Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>,
Wolfram Sang <wsa@kernel.org>
Subject: [PATCH v2 3/6] i2c: xiic: Defer xiic_wakeup() and __xiic_start_xfer() in xiic_process()
Date: Mon, 23 Aug 2021 23:41:42 +0200 [thread overview]
Message-ID: <20210823214145.295104-4-marex@denx.de> (raw)
In-Reply-To: <20210823214145.295104-1-marex@denx.de>
The __xiic_start_xfer() manipulates the interrupt flags, xiic_wakeup()
may result in return from xiic_xfer() early. Defer both to the end of
the xiic_process() interrupt thread, so that they are executed after
all the other interrupt bits handling completed and once it completely
safe to perform changes to the interrupt bits in the hardware.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Cc: Wolfram Sang <wsa@kernel.org>
---
V2: No change
---
drivers/i2c/busses/i2c-xiic.c | 37 ++++++++++++++++++++++++-----------
1 file changed, 26 insertions(+), 11 deletions(-)
diff --git a/drivers/i2c/busses/i2c-xiic.c b/drivers/i2c/busses/i2c-xiic.c
index b13166e94d894..aecdeec579977 100644
--- a/drivers/i2c/busses/i2c-xiic.c
+++ b/drivers/i2c/busses/i2c-xiic.c
@@ -375,6 +375,9 @@ static irqreturn_t xiic_process(int irq, void *dev_id)
struct xiic_i2c *i2c = dev_id;
u32 pend, isr, ier;
u32 clr = 0;
+ int xfer_more = 0;
+ int wakeup_req = 0;
+ int wakeup_code = 0;
/* Get the interrupt Status from the IPIF. There is no clearing of
* interrupts in the IPIF. Interrupts must be cleared at the source.
@@ -411,10 +414,14 @@ static irqreturn_t xiic_process(int irq, void *dev_id)
*/
xiic_reinit(i2c);
- if (i2c->rx_msg)
- xiic_wakeup(i2c, STATE_ERROR);
- if (i2c->tx_msg)
- xiic_wakeup(i2c, STATE_ERROR);
+ if (i2c->rx_msg) {
+ wakeup_req = 1;
+ wakeup_code = STATE_ERROR;
+ }
+ if (i2c->tx_msg) {
+ wakeup_req = 1;
+ wakeup_code = STATE_ERROR;
+ }
}
if (pend & XIIC_INTR_RX_FULL_MASK) {
/* Receive register/FIFO is full */
@@ -448,8 +455,7 @@ static irqreturn_t xiic_process(int irq, void *dev_id)
i2c->tx_msg++;
dev_dbg(i2c->adap.dev.parent,
"%s will start next...\n", __func__);
-
- __xiic_start_xfer(i2c);
+ xfer_more = 1;
}
}
}
@@ -463,11 +469,13 @@ static irqreturn_t xiic_process(int irq, void *dev_id)
if (!i2c->tx_msg)
goto out;
- if ((i2c->nmsgs == 1) && !i2c->rx_msg &&
- xiic_tx_space(i2c) == 0)
- xiic_wakeup(i2c, STATE_DONE);
+ wakeup_req = 1;
+
+ if (i2c->nmsgs == 1 && !i2c->rx_msg &&
+ xiic_tx_space(i2c) == 0)
+ wakeup_code = STATE_DONE;
else
- xiic_wakeup(i2c, STATE_ERROR);
+ wakeup_code = STATE_ERROR;
}
if (pend & (XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK)) {
/* Transmit register/FIFO is empty or ½ empty */
@@ -491,7 +499,7 @@ static irqreturn_t xiic_process(int irq, void *dev_id)
if (i2c->nmsgs > 1) {
i2c->nmsgs--;
i2c->tx_msg++;
- __xiic_start_xfer(i2c);
+ xfer_more = 1;
} else {
xiic_irq_dis(i2c, XIIC_INTR_TX_HALF_MASK);
@@ -509,6 +517,13 @@ static irqreturn_t xiic_process(int irq, void *dev_id)
dev_dbg(i2c->adap.dev.parent, "%s clr: 0x%x\n", __func__, clr);
xiic_setreg32(i2c, XIIC_IISR_OFFSET, clr);
+ if (xfer_more)
+ __xiic_start_xfer(i2c);
+ if (wakeup_req)
+ xiic_wakeup(i2c, wakeup_code);
+
+ WARN_ON(xfer_more && wakeup_req);
+
mutex_unlock(&i2c->lock);
return IRQ_HANDLED;
}
--
2.32.0
next prev parent reply other threads:[~2021-08-23 21:42 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-23 21:41 [PATCH v2 0/6] i2c: xiic: Fix broken locking Marek Vasut
2021-08-23 21:41 ` [PATCH v2 1/6] i2c: xiic: Fix broken locking on tx_msg Marek Vasut
2021-08-23 21:41 ` [PATCH v2 2/6] i2c: xiic: Drop broken interrupt handler Marek Vasut
2021-08-23 21:41 ` Marek Vasut [this message]
2021-08-23 21:41 ` [PATCH v2 4/6] i2c: xiic: Switch from waitqueue to completion Marek Vasut
2021-08-23 21:41 ` [PATCH v2 5/6] i2c: xiic: Only ever transfer single message Marek Vasut
2021-08-23 21:41 ` [PATCH v2 6/6] i2c: xiic: Fix RX IRQ busy check Marek Vasut
2021-08-24 6:58 ` [PATCH v2 0/6] i2c: xiic: Fix broken locking Michal Simek
2021-08-27 8:31 ` Raviteja Narayanam
2021-08-27 8:34 ` Michal Simek
2021-09-14 10:29 ` Wolfram Sang
2021-09-14 11:54 ` Michal Simek
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