Patchwork [U-Boot,v1,1/2] bfin: Remove spi dma function in bf5xx.

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Submitter Sonic Zhang
Date March 4, 2013, 7:20 a.m.
Message ID <1362381609-23716-1-git-send-email-sonic.adi@gmail.com>
Download mbox | patch
Permalink /patch/224602/
State Accepted
Delegated to: Sonic Zhang
Headers show

Comments

Sonic Zhang - March 4, 2013, 7:20 a.m.
From: Scott Jiang <scott.jiang.linux@gmail.com>

BF5xx rx dma causes spi flash random read error.
Accually spi controller has problems both on tx and rx dma.
So remove spi dma support in u-boot.

Signed-off-by: Scott Jiang <scott.jiang.linux@gmail.com>
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
---
 drivers/spi/bfin_spi.c |  103 +-----------------------------------------------
 1 files changed, 1 insertions(+), 102 deletions(-)
Mike Frysinger - March 12, 2013, 11:19 a.m.
On Monday 04 March 2013 02:20:08 Sonic Zhang wrote:
> From: Scott Jiang <scott.jiang.linux@gmail.com>
> 
> BF5xx rx dma causes spi flash random read error.
> Accually spi controller has problems both on tx and rx dma.
> So remove spi dma support in u-boot.

this is wrong, and imo, unnecessary.  it's wrong because using DMA gains a lot 
of speed increases, and works for in many cases (i haven't seen cases where it 
didn't work, but i haven't been actively developing in the last year of 
course).  it's unnecessary because there's already a CONFIG_xxx option to 
disable it if your platform is having problems and you can't figure things out, 
and don't need the speed gains.
-mike
Scott Jiang - March 13, 2013, 3:13 a.m.
Mike,

test case is [#6887], if you save data and read out to compare it
sometimes fail.
I agree that we can keep this patch, but it introduces problems to
test engineer.
This is a random error, she is difficult to know which board and which case we
should enable this function.

2013/3/12 Mike Frysinger <vapier@gentoo.org>:
> On Monday 04 March 2013 02:20:08 Sonic Zhang wrote:
>> From: Scott Jiang <scott.jiang.linux@gmail.com>
>>
>> BF5xx rx dma causes spi flash random read error.
>> Accually spi controller has problems both on tx and rx dma.
>> So remove spi dma support in u-boot.
>
> this is wrong, and imo, unnecessary.  it's wrong because using DMA gains a lot
> of speed increases, and works for in many cases (i haven't seen cases where it
> didn't work, but i haven't been actively developing in the last year of
> course).  it's unnecessary because there's already a CONFIG_xxx option to
> disable it if your platform is having problems and you can't figure things out,
> and don't need the speed gains.
> -mike

Patch

diff --git a/drivers/spi/bfin_spi.c b/drivers/spi/bfin_spi.c
index e080bec..fff384a 100644
--- a/drivers/spi/bfin_spi.c
+++ b/drivers/spi/bfin_spi.c
@@ -13,7 +13,6 @@ 
 #include <spi.h>
 
 #include <asm/blackfin.h>
-#include <asm/dma.h>
 #include <asm/gpio.h>
 #include <asm/portmux.h>
 #include <asm/mach-common/bits/spi.h>
@@ -244,106 +243,10 @@  void spi_release_bus(struct spi_slave *slave)
 	SSYNC();
 }
 
-#ifdef __ADSPBF54x__
-# define SPI_DMA_BASE DMA4_NEXT_DESC_PTR
-#elif defined(__ADSPBF533__) || defined(__ADSPBF532__) || defined(__ADSPBF531__) || \
-      defined(__ADSPBF538__) || defined(__ADSPBF539__)
-# define SPI_DMA_BASE DMA5_NEXT_DESC_PTR
-#elif defined(__ADSPBF561__)
-# define SPI_DMA_BASE DMA2_4_NEXT_DESC_PTR
-#elif defined(__ADSPBF537__) || defined(__ADSPBF536__) || defined(__ADSPBF534__) || \
-      defined(__ADSPBF52x__) || defined(__ADSPBF51x__)
-# define SPI_DMA_BASE DMA7_NEXT_DESC_PTR
-# elif defined(__ADSPBF50x__)
-# define SPI_DMA_BASE DMA6_NEXT_DESC_PTR
-#else
-# error "Please provide SPI DMA channel defines"
-#endif
-static volatile struct dma_register *dma = (void *)SPI_DMA_BASE;
-
 #ifndef CONFIG_BFIN_SPI_IDLE_VAL
 # define CONFIG_BFIN_SPI_IDLE_VAL 0xff
 #endif
 
-#ifdef CONFIG_BFIN_SPI_NO_DMA
-# define SPI_DMA 0
-#else
-# define SPI_DMA 1
-#endif
-
-static int spi_dma_xfer(struct bfin_spi_slave *bss, const u8 *tx, u8 *rx,
-			uint bytes)
-{
-	int ret = -1;
-	u16 ndsize, spi_config, dma_config;
-	struct dmasg dmasg[2];
-	const u8 *buf;
-
-	if (tx) {
-		debug("%s: doing half duplex TX\n", __func__);
-		buf = tx;
-		spi_config = TDBR_DMA;
-		dma_config = 0;
-	} else {
-		debug("%s: doing half duplex RX\n", __func__);
-		buf = rx;
-		spi_config = RDBR_DMA;
-		dma_config = WNR;
-	}
-
-	dmasg[0].start_addr = (unsigned long)buf;
-	dmasg[0].x_modify = 1;
-	dma_config |= WDSIZE_8 | DMAEN;
-	if (bytes <= 65536) {
-		blackfin_dcache_flush_invalidate_range(buf, buf + bytes);
-		ndsize = NDSIZE_5;
-		dmasg[0].cfg = NDSIZE_0 | dma_config | FLOW_STOP | DI_EN;
-		dmasg[0].x_count = bytes;
-	} else {
-		blackfin_dcache_flush_invalidate_range(buf, buf + 65536 - 1);
-		ndsize = NDSIZE_7;
-		dmasg[0].cfg = NDSIZE_5 | dma_config | FLOW_ARRAY | DMA2D;
-		dmasg[0].x_count = 0;	/* 2^16 */
-		dmasg[0].y_count = bytes >> 16;	/* count / 2^16 */
-		dmasg[0].y_modify = 1;
-		dmasg[1].start_addr = (unsigned long)(buf + (bytes & ~0xFFFF));
-		dmasg[1].cfg = NDSIZE_0 | dma_config | FLOW_STOP | DI_EN;
-		dmasg[1].x_count = bytes & 0xFFFF; /* count % 2^16 */
-		dmasg[1].x_modify = 1;
-	}
-
-	dma->cfg = 0;
-	dma->irq_status = DMA_DONE | DMA_ERR;
-	dma->curr_desc_ptr = dmasg;
-	write_SPI_CTL(bss, (bss->ctl & ~TDBR_CORE));
-	write_SPI_STAT(bss, -1);
-	SSYNC();
-
-	write_SPI_TDBR(bss, CONFIG_BFIN_SPI_IDLE_VAL);
-	dma->cfg = ndsize | FLOW_ARRAY | DMAEN;
-	write_SPI_CTL(bss, (bss->ctl & ~TDBR_CORE) | spi_config);
-	SSYNC();
-
-	/*
-	 * We already invalidated the first 64k,
-	 * now while we just wait invalidate the remaining part.
-	 * Its not likely that the DMA is going to overtake
-	 */
-	if (bytes > 65536)
-		blackfin_dcache_flush_invalidate_range(buf + 65536, buf + bytes);
-
-	while (!(dma->irq_status & DMA_DONE))
-		if (ctrlc())
-			goto done;
-
-	dma->cfg = 0;
-
-	ret = 0;
- done:
-	write_SPI_CTL(bss, bss->ctl);
-	return ret;
-}
-
 static int spi_pio_xfer(struct bfin_spi_slave *bss, const u8 *tx, u8 *rx,
 			uint bytes)
 {
@@ -395,11 +298,7 @@  int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
 	if (flags & SPI_XFER_BEGIN)
 		spi_cs_activate(slave);
 
-	/* TX DMA doesn't work quite right */
-	if (SPI_DMA && bytes > 6 && (!tx /*|| !rx*/))
-		ret = spi_dma_xfer(bss, tx, rx, bytes);
-	else
-		ret = spi_pio_xfer(bss, tx, rx, bytes);
+	ret = spi_pio_xfer(bss, tx, rx, bytes);
 
  done:
 	if (flags & SPI_XFER_END)