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Subject[PATCH v5 02/16] spi: dw: Return any value retrieved from the dma_transfer callback
Date
DW APB SSI DMA may need to perform the synchronous operations. In that
case the dma_transfer() callback will return 0 as a marker of the SPI
transfer being finished so the SPI core can proceed with the SPI
message trasnfers pumping procedure. This will be needed to fix the
problem when DMA transactions are finished, but there is still data
left in the SPI Tx/Rx buffers. But for now make dma_transfer to
return 1 as the normal dw_spi_transfer_one() method.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Georgy Vlasov <Georgy.Vlasov@baikalelectronics.ru>
Cc: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org
---
drivers/spi/spi-dw-mid.c | 2 +-
drivers/spi/spi-dw.c | 7 ++-----
2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/spi/spi-dw-mid.c b/drivers/spi/spi-dw-mid.c
index b1710132b7b2..7ff1acaa55f8 100644
--- a/drivers/spi/spi-dw-mid.c
+++ b/drivers/spi/spi-dw-mid.c
@@ -288,7 +288,7 @@ static int mid_spi_dma_transfer(struct dw_spi *dws, struct spi_transfer *xfer)
dma_async_issue_pending(dws->txchan);
}

- return 0;
+ return 1;
}

static void mid_spi_dma_stop(struct dw_spi *dws)
diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
index 050cb2ea0812..6939e003e3e9 100644
--- a/drivers/spi/spi-dw.c
+++ b/drivers/spi/spi-dw.c
@@ -389,11 +389,8 @@ static int dw_spi_transfer_one(struct spi_controller *master,

spi_enable_chip(dws, 1);

- if (dws->dma_mapped) {
- ret = dws->dma_ops->dma_transfer(dws, transfer);
- if (ret < 0)
- return ret;
- }
+ if (dws->dma_mapped)
+ return dws->dma_ops->dma_transfer(dws, transfer);

return 1;
}
--
2.26.2
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