From: Mike Frysinger <vapier.adi@gmail.com>
Date: Tue, 7 Apr 2009 02:00:43 +0000 (-0700)
Subject: Blackfin SPI Driver: tweak magic spi dma sequence to get it working on BF54x
X-Git-Tag: firefly_0821_release~14687
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=a963ea83b316b0a3ebf1c7118a6c36b5cd334bb6;p=firefly-linux-kernel-4.4.55.git

Blackfin SPI Driver: tweak magic spi dma sequence to get it working on BF54x

Without this change, SPI DMA is not reliably under stress tests.
Obiviously it's a hardware issue which is not addressed by any document.

Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c
index e706de1d10c8..317731a9cd6d 100644
--- a/drivers/spi/spi_bfin5xx.c
+++ b/drivers/spi/spi_bfin5xx.c
@@ -862,8 +862,9 @@ static void pump_transfers(unsigned long data)
 		set_dma_start_addr(drv_data->dma_channel, dma_start_addr);
 		set_dma_config(drv_data->dma_channel, dma_config);
 		local_irq_save(flags);
-		enable_dma(drv_data->dma_channel);
+		SSYNC();
 		write_CTRL(drv_data, cr);
+		enable_dma(drv_data->dma_channel);
 		dma_enable_irq(drv_data->dma_channel);
 		local_irq_restore(flags);