linux-kernel - [PATCH v2 11/21] spi: dw: Unmask IRQs after enabling the chip

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Date:   Wed, 30 Sep 2020 21:55:35 +0300
From:   Serge Semin <Sergey.Semin@...kalelectronics.ru>
To:     Mark Brown <broonie@...nel.org>
CC:     Serge Semin <Sergey.Semin@...kalelectronics.ru>,
        Serge Semin <fancer.lancer@...il.com>,
        Alexey Malahov <Alexey.Malahov@...kalelectronics.ru>,
        Ramil Zaripov <Ramil.Zaripov@...kalelectronics.ru>,
        Pavel Parkhomenko <Pavel.Parkhomenko@...kalelectronics.ru>,
        Andy Shevchenko <andy.shevchenko@...il.com>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Lars Povlsen <lars.povlsen@...rochip.com>,
        "wuxu . wu" <wuxu.wu@...wei.com>, Feng Tang <feng.tang@...el.com>,
        Rob Herring <robh+dt@...nel.org>, <linux-spi@...r.kernel.org>,
        <devicetree@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: [PATCH v2 11/21] spi: dw: Unmask IRQs after enabling the chip

It's theoretically erroneous to enable IRQ before the chip is turned on.
If IRQ handler gets executed before the chip is enabled, then any data
written to the Tx FIFO will be just ignored.

I say "theoretically" because we haven't noticed any problem with that,
but let's fix it anyway just in case...

Signed-off-by: Serge Semin <Sergey.Semin@...kalelectronics.ru>
---
 drivers/spi/spi-dw-core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-dw-core.c b/drivers/spi/spi-dw-core.c
index db3fec4195f7..58a7c7465c61 100644
--- a/drivers/spi/spi-dw-core.c
+++ b/drivers/spi/spi-dw-core.c
@@ -376,8 +376,6 @@ static int dw_spi_transfer_one(struct spi_controller *master,
 			spi_enable_chip(dws, 1);
 			return ret;
 		}
-	} else {
-		dw_spi_irq_setup(dws);
 	}
 
 	spi_enable_chip(dws, 1);
@@ -385,6 +383,8 @@ static int dw_spi_transfer_one(struct spi_controller *master,
 	if (dws->dma_mapped)
 		return dws->dma_ops->dma_transfer(dws, transfer);
 
+	dw_spi_irq_setup(dws);
+
 	return 1;
 }
 
-- 
2.27.0