Unverified Commit 80ab9012 authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Mark Brown
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spi: topcliff-pch: Prevent usage of potentially stale DMA device 



DMA device is expected to be available while SPI transfer is ongoing.

Prevent usage of potentially stale DMA device by keeping reference
count till the end of the transfer.

Fixes: 4d986ffa ("spi: add missing pci_dev_put() before return")
Reported-by: default avatarChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220307173740.80996-1-andriy.shevchenko@linux.intel.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent b15e3bc7

drivers/spi/spi-topcliff-pch.c

+6 −2
Original line number Diff line number Diff line
@@ -103,6 +103,7 @@ 
static int use_dma = 1;



struct pch_spi_dma_ctrl {

	struct pci_dev		*dma_dev;

	struct dma_async_tx_descriptor	*desc_tx;

	struct dma_async_tx_descriptor	*desc_rx;

	struct pch_dma_slave		param_tx;
@@ -876,7 +877,6 @@ static void pch_spi_request_dma(struct pch_spi_data *data, int bpw) 
	if (!chan) {

		dev_err(&data->master->dev,

			"ERROR: dma_request_channel FAILS(Tx)\n");

		data->use_dma = 0;

		goto out;

	}

	dma->chan_tx = chan;
@@ -893,13 +893,15 @@ static void pch_spi_request_dma(struct pch_spi_data *data, int bpw) 
			"ERROR: dma_request_channel FAILS(Rx)\n");

		dma_release_channel(dma->chan_tx);

		dma->chan_tx = NULL;

		data->use_dma = 0;

		goto out;

	}

	dma->chan_rx = chan;



	dma->dma_dev = dma_dev;

	return;

out:

	pci_dev_put(dma_dev);

	data->use_dma = 0;

}



static void pch_spi_release_dma(struct pch_spi_data *data)
@@ -915,6 +917,8 @@ static void pch_spi_release_dma(struct pch_spi_data *data) 
		dma_release_channel(dma->chan_rx);

		dma->chan_rx = NULL;

	}



	pci_dev_put(dma->dma_dev);

}



static void pch_spi_handle_dma(struct pch_spi_data *data, int *bpw)