From 8c3ad488fe0e4478b3b29b9501074c5fb1bfda0d Mon Sep 17 00:00:00 2001
From: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Date: Thu, 24 Mar 2016 15:35:44 +0200
Subject: spi: pxa2xx: Use dummy buffers provided by SPI core

Dummy buffer is used for half duplex transfers that don't have TX or RX
buffer set. Instead of own dummy buffer management here let the SPI core to
handle it by setting the SPI_MASTER_MUST_RX and SPI_MASTER_MUST_TX flags.
Then core makes sure both transfer buffers are set.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-pxa2xx-dma.c b/drivers/spi/spi-pxa2xx-dma.c
index 624cb06..a18a03d 100644
--- a/drivers/spi/spi-pxa2xx-dma.c
+++ b/drivers/spi/spi-pxa2xx-dma.c
@@ -53,11 +53,7 @@ static int pxa2xx_spi_map_dma_buffer(struct driver_data *drv_data,
 	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
 		size_t bytes = min_t(size_t, len, SZ_2K);
 
-		if (buf)
-			sg_set_buf(sg, pbuf, bytes);
-		else
-			sg_set_buf(sg, drv_data->dummy, bytes);
-
+		sg_set_buf(sg, pbuf, bytes);
 		pbuf += bytes;
 		len -= bytes;
 	}
@@ -312,10 +308,6 @@ int pxa2xx_spi_dma_setup(struct driver_data *drv_data)
 	dma_cap_zero(mask);
 	dma_cap_set(DMA_SLAVE, mask);
 
-	drv_data->dummy = devm_kzalloc(dev, SZ_2K, GFP_KERNEL);
-	if (!drv_data->dummy)
-		return -ENOMEM;
-
 	drv_data->tx_chan = dma_request_slave_channel_compat(mask,
 				pdata->dma_filter, pdata->tx_param, dev, "tx");
 	if (!drv_data->tx_chan)
diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
index 47bdbd3..86c155a 100644
--- a/drivers/spi/spi-pxa2xx.c
+++ b/drivers/spi/spi-pxa2xx.c
@@ -1562,6 +1562,7 @@ static int pxa2xx_spi_probe(struct platform_device *pdev)
 	master->unprepare_transfer_hardware = pxa2xx_spi_unprepare_transfer;
 	master->fw_translate_cs = pxa2xx_spi_fw_translate_cs;
 	master->auto_runtime_pm = true;
+	master->flags = SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX;
 
 	drv_data->ssp_type = ssp->type;
 
diff --git a/drivers/spi/spi-pxa2xx.h b/drivers/spi/spi-pxa2xx.h
index 85017f9..e6b0900 100644
--- a/drivers/spi/spi-pxa2xx.h
+++ b/drivers/spi/spi-pxa2xx.h
@@ -56,7 +56,6 @@ struct driver_data {
 	struct sg_table tx_sgt;
 	int rx_nents;
 	int tx_nents;
-	void *dummy;
 	atomic_t dma_running;
 
 	/* Current message transfer state info */
-- 
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