linux-kernel - [PATCH 2/3] i2c: qcom-geni: Propagate GENI_ABORT_DONE to geni_i2c_abort

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Date:   Sat, 16 Jul 2022 20:50:26 -0700
From:   Bjorn Andersson <bjorn.andersson@...aro.org>
To:     Bjorn Andersson <bjorn.andersson@...aro.org>,
        Konrad Dybcio <konrad.dybcio@...ainline.org>,
        Vinod Koul <vkoul@...nel.org>, Wolfram Sang <wsa@...nel.org>
Cc:     linux-arm-msm@...r.kernel.org, linux-i2c@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH 2/3] i2c: qcom-geni: Propagate GENI_ABORT_DONE to geni_i2c_abort_xfer()

Waiting for M_CMD_ABORT_EN in geni_i2c_abort_xfer() races with the
interrupt handler which will read and clear the abort bit, the result is
that every abort attempt takes 1 second and is followed by a message
about the abort having times out.

Introduce a new state variable to carry the abort_done state from the
interrupt handler back to geni_i2c_abort_xfer().

Signed-off-by: Bjorn Andersson <bjorn.andersson@...aro.org>
---
 drivers/i2c/busses/i2c-qcom-geni.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
index 3bec7c782824..e212e7ae7ad2 100644
--- a/drivers/i2c/busses/i2c-qcom-geni.c
+++ b/drivers/i2c/busses/i2c-qcom-geni.c
@@ -97,6 +97,7 @@ struct geni_i2c_dev {
 	struct dma_chan *tx_c;
 	struct dma_chan *rx_c;
 	bool gpi_mode;
+	bool abort_done;
 };
 
 struct geni_i2c_err_log {
@@ -203,9 +204,14 @@ static void geni_i2c_err(struct geni_i2c_dev *gi2c, int err)
 		dev_dbg(gi2c->se.dev, "len:%d, slv-addr:0x%x, RD/WR:%d\n",
 			gi2c->cur->len, gi2c->cur->addr, gi2c->cur->flags);
 
-	if (err != NACK && err != GENI_ABORT_DONE) {
+	switch (err) {
+	case GENI_ABORT_DONE:
+		gi2c->abort_done = true;
+		break;
+	default:
 		dev_err(gi2c->se.dev, "%s\n", gi2c_log[err].msg);
 		geni_i2c_err_misc(gi2c);
+		break;
 	}
 }
 
@@ -311,21 +317,21 @@ static irqreturn_t geni_i2c_irq(int irq, void *dev)
 
 static void geni_i2c_abort_xfer(struct geni_i2c_dev *gi2c)
 {
-	u32 val;
 	unsigned long time_left = ABORT_TIMEOUT;
 	unsigned long flags;
 
 	spin_lock_irqsave(&gi2c->lock, flags);
 	geni_i2c_err(gi2c, GENI_TIMEOUT);
 	gi2c->cur = NULL;
+	gi2c->abort_done = false;
 	geni_se_abort_m_cmd(&gi2c->se);
 	spin_unlock_irqrestore(&gi2c->lock, flags);
+
 	do {
 		time_left = wait_for_completion_timeout(&gi2c->done, time_left);
-		val = readl_relaxed(gi2c->se.base + SE_GENI_M_IRQ_STATUS);
-	} while (!(val & M_CMD_ABORT_EN) && time_left);
+	} while (!gi2c->abort_done && time_left);
 
-	if (!(val & M_CMD_ABORT_EN))
+	if (!time_left)
 		dev_err(gi2c->se.dev, "Timeout abort_m_cmd\n");
 }
 
-- 
2.35.1