Re: [PATCH 1/3] ata: sata_dwc_460ex: use "dmas" DT property to find dma channel

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

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On Sun, 2015-12-20 at 22:55 +0200, Andy Shevchenko wrote:
> On Sun, Dec 20, 2015 at 10:17 PM, Andy Shevchenko
> <andy.shevchenko@gmail.com> wrote:
> > On Sun, Dec 20, 2015 at 8:49 PM, Måns Rullgård <mans@mansr.com>
> > wrote:
> > I noticed thanks to DWC_PARAMS that burst size is hardcoded to 32
> > items on this board, however registers for SATA program it to 64. I
> > remember that I got no interrupt when I programmed transfer width
> > wrongly (64 bits against 32 bits) when I ported dw_dmac to be used
> > on
> > Intel SoCs.
> 
> One more thing, I have a patch to monitor DMA IO, we may check what
> exactly the values are written / read  in DMA. I can share it
> tomorrow.

As promised the patch I have to debug IO of DW DMA. Didn't check though
if it applies cleanly on top of recent vanilla kernel.

-- 
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy

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From c824845238f0e027d480bfc3b9ad482ae901b78b Mon Sep 17 00:00:00 2001
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Mon, 4 Jun 2012 10:14:50 +0300
Subject: [PATCH v2] dw_dmac: debug dma controller IO

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/dma/dw/core.c |  8 +++++---
 drivers/dma/dw/regs.h | 26 ++++++++++++++++++++++++++
 2 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index dcf19f0..d50c39c 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -570,9 +570,10 @@ static void dwc_handle_cyclic(struct dw_dma *dw, struct dw_dma_chan *dwc,
 	if (dwc->mask) {
 		void (*callback)(void *param);
 		void *callback_param;
+		dma_addr_t llp = channel_readl(dwc, LLP);
 
-		dev_vdbg(chan2dev(&dwc->chan), "new cyclic period llp 0x%08x\n",
-				channel_readl(dwc, LLP));
+		dev_vdbg(chan2dev(&dwc->chan), "new cyclic period llp %pad\n",
+				&llp);
 
 		callback = dwc->cdesc->period_callback;
 		callback_param = dwc->cdesc->period_callback_param;
@@ -1571,6 +1572,8 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata)
 
 	pm_runtime_get_sync(chip->dev);
 
+	dw->dma.dev = chip->dev;
+
 	dw_params = dma_read_byaddr(chip->regs, DW_PARAMS);
 	autocfg = dw_params >> DW_PARAMS_EN & 0x1;
 
@@ -1715,7 +1718,6 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata)
 	dma_cap_set(DMA_SLAVE, dw->dma.cap_mask);
 	if (pdata->is_private)
 		dma_cap_set(DMA_PRIVATE, dw->dma.cap_mask);
-	dw->dma.dev = chip->dev;
 	dw->dma.device_alloc_chan_resources = dwc_alloc_chan_resources;
 	dw->dma.device_free_chan_resources = dwc_free_chan_resources;
 
diff --git a/drivers/dma/dw/regs.h b/drivers/dma/dw/regs.h
index 3a3a5e1..a3b881c 100644
--- a/drivers/dma/dw/regs.h
+++ b/drivers/dma/dw/regs.h
@@ -130,6 +130,8 @@ struct dw_dma_regs {
 #define dma_writel_native writel
 #endif
 
+#define DW_DMAC_IO_DEBUG
+
 /* To access the registers in early stage of probe */
 #define dma_read_byaddr(addr, name) \
 	dma_readl_native((addr) + offsetof(struct dw_dma_regs, name))
@@ -301,10 +303,22 @@ __dwc_regs(struct dw_dma_chan *dwc)
 	return dwc->ch_regs;
 }
 
+#ifdef DW_DMAC_IO_DEBUG
+#define channel_readl(dwc, name) ({						\
+	unsigned int val = dma_readl_native(&(__dwc_regs(dwc)->name));		\
+	dev_dbg(chan2dev(&dwc->chan), "readl: " #name " 0x%08x\n", (u32)val);	\
+	val;									\
+})
+#define channel_writel(dwc, name, val) ({					\
+	dev_dbg(chan2dev(&dwc->chan), "writel: " #name " 0x%08x\n", (u32)val);	\
+	dma_writel_native((val), &(__dwc_regs(dwc)->name));			\
+})
+#else
 #define channel_readl(dwc, name) \
 	dma_readl_native(&(__dwc_regs(dwc)->name))
 #define channel_writel(dwc, name, val) \
 	dma_writel_native((val), &(__dwc_regs(dwc)->name))
+#endif
 
 static inline struct dw_dma_chan *to_dw_dma_chan(struct dma_chan *chan)
 {
@@ -333,10 +347,22 @@ static inline struct dw_dma_regs __iomem *__dw_regs(struct dw_dma *dw)
 	return dw->regs;
 }
 
+#ifdef DW_DMAC_IO_DEBUG
+#define dma_readl(dw, name) ({						\
+	unsigned int val = dma_readl_native(&(__dw_regs(dw)->name));	\
+	dev_dbg(dw->dma.dev, "readl: " #name " 0x%08x\n", (u32)val);	\
+	val;								\
+})
+#define dma_writel(dw, name, val) ({					\
+	dev_dbg(dw->dma.dev, "writel: " #name " 0x%08x\n", (u32)val);	\
+	dma_writel_native((val), &(__dw_regs(dw)->name));		\
+})
+#else
 #define dma_readl(dw, name) \
 	dma_readl_native(&(__dw_regs(dw)->name))
 #define dma_writel(dw, name, val) \
 	dma_writel_native((val), &(__dw_regs(dw)->name))
+#endif
 
 #define channel_set_bit(dw, reg, mask) \
 	dma_writel(dw, reg, ((mask) << 8) | (mask))
-- 
2.1.3