From 210012a6cd8770a73d1aa74b742667b462d04511 Mon Sep 17 00:00:00 2001 From: Jassi Brar Date: Thu, 5 Nov 2009 13:44:20 +0900 Subject: ARM: S3C64XX: DMA: Protect buffer pointers while manipulation Ensure the DMA buffer points are not updated from another source during the process of enquing a buffer. Signed-off-by: Jassi Brar [ben-linux@fluff.org: Updated patch comment] Signed-off-by: Ben Dooks --- arch/arm/plat-s3c64xx/dma.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'arch') diff --git a/arch/arm/plat-s3c64xx/dma.c b/arch/arm/plat-s3c64xx/dma.c index 266a10745a8..6fa706f0f42 100644 --- a/arch/arm/plat-s3c64xx/dma.c +++ b/arch/arm/plat-s3c64xx/dma.c @@ -339,6 +339,7 @@ int s3c2410_dma_enqueue(unsigned int channel, void *id, struct s3c64xx_dma_buff *next; struct s3c64xx_dma_buff *buff; struct pl080s_lli *lli; + unsigned long flags; int ret; WARN_ON(!chan); @@ -366,6 +367,8 @@ int s3c2410_dma_enqueue(unsigned int channel, void *id, s3c64xx_dma_fill_lli(chan, lli, data, size); + local_irq_save(flags); + if ((next = chan->next) != NULL) { struct s3c64xx_dma_buff *end = chan->end; struct pl080s_lli *endlli = end->lli; @@ -397,6 +400,8 @@ int s3c2410_dma_enqueue(unsigned int channel, void *id, s3c64xx_lli_to_regs(chan, lli); } + local_irq_restore(flags); + show_lli(lli); dbg_showchan(chan); -- cgit v1.2.3 From 6d0b8627d545aed7d4bcaad2156b6cb95e105715 Mon Sep 17 00:00:00 2001 From: Jassi Brar Date: Thu, 5 Nov 2009 13:44:26 +0900 Subject: ARM: S3C64XX: DMA: Unify callback functions for success/failure Replace s3c64xx_dma_tcirq and s3c64xx_dma_errirq with the common s3c64xx_dma_buffdone. Signed-off-by: Jassi Brar Signed-off-by: Ben Dooks --- arch/arm/plat-s3c64xx/dma.c | 34 +++++++++++++--------------------- 1 file changed, 13 insertions(+), 21 deletions(-) (limited to 'arch') diff --git a/arch/arm/plat-s3c64xx/dma.c b/arch/arm/plat-s3c64xx/dma.c index 6fa706f0f42..5a08a86419d 100644 --- a/arch/arm/plat-s3c64xx/dma.c +++ b/arch/arm/plat-s3c64xx/dma.c @@ -565,26 +565,11 @@ int s3c2410_dma_free(unsigned int channel, struct s3c2410_dma_client *client) EXPORT_SYMBOL(s3c2410_dma_free); - -static void s3c64xx_dma_tcirq(struct s3c64xx_dmac *dmac, int offs) -{ - struct s3c2410_dma_chan *chan = dmac->channels + offs; - - /* note, we currently do not bother to work out which buffer - * or buffers have been completed since the last tc-irq. */ - - if (chan->callback_fn) - (chan->callback_fn)(chan, chan->curr->pw, 0, S3C2410_RES_OK); -} - -static void s3c64xx_dma_errirq(struct s3c64xx_dmac *dmac, int offs) -{ - printk(KERN_DEBUG "%s: offs %d\n", __func__, offs); -} - static irqreturn_t s3c64xx_dma_irq(int irq, void *pw) { struct s3c64xx_dmac *dmac = pw; + struct s3c2410_dma_chan *chan; + enum s3c2410_dma_buffresult res; u32 tcstat, errstat; u32 bit; int offs; @@ -593,15 +578,22 @@ static irqreturn_t s3c64xx_dma_irq(int irq, void *pw) errstat = readl(dmac->regs + PL080_ERR_STATUS); for (offs = 0, bit = 1; offs < 8; offs++, bit <<= 1) { + + if (!(errstat & bit) && !(tcstat & bit)) + continue; + + chan = dmac->channels + offs; + res = S3C2410_RES_ERR; + if (tcstat & bit) { writel(bit, dmac->regs + PL080_TC_CLEAR); - s3c64xx_dma_tcirq(dmac, offs); + res = S3C2410_RES_OK; } - if (errstat & bit) { - s3c64xx_dma_errirq(dmac, offs); + if (errstat & bit) writel(bit, dmac->regs + PL080_ERR_CLEAR); - } + + s3c64xx_dma_bufffdone(chan, chan->curr, res); } return IRQ_HANDLED; -- cgit v1.2.3 From 7507f39c57d4a285aea11c379fbc65c2b3f375ef Mon Sep 17 00:00:00 2001 From: Jassi Brar Date: Thu, 5 Nov 2009 13:44:45 +0900 Subject: ARM: S3C64XX: DMA: Make src and dst transfer size same Some devices don't seem to work if the source and desitnation transfer widths are not same. For example, SPI dma xfers, with 8bits/word, don't work without this patch. Signed-off-by: Jassi Brar Signed-off-by: Ben Dooks --- arch/arm/plat-s3c64xx/dma.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'arch') diff --git a/arch/arm/plat-s3c64xx/dma.c b/arch/arm/plat-s3c64xx/dma.c index 5a08a86419d..a94281bb84d 100644 --- a/arch/arm/plat-s3c64xx/dma.c +++ b/arch/arm/plat-s3c64xx/dma.c @@ -151,8 +151,6 @@ static void s3c64xx_dma_fill_lli(struct s3c2410_dma_chan *chan, src = chan->dev_addr; dst = data; control0 = PL080_CONTROL_SRC_AHB2; - control0 |= (u32)chan->hw_width << PL080_CONTROL_SWIDTH_SHIFT; - control0 |= 2 << PL080_CONTROL_DWIDTH_SHIFT; control0 |= PL080_CONTROL_DST_INCR; break; @@ -160,8 +158,6 @@ static void s3c64xx_dma_fill_lli(struct s3c2410_dma_chan *chan, src = data; dst = chan->dev_addr; control0 = PL080_CONTROL_DST_AHB2; - control0 |= (u32)chan->hw_width << PL080_CONTROL_DWIDTH_SHIFT; - control0 |= 2 << PL080_CONTROL_SWIDTH_SHIFT; control0 |= PL080_CONTROL_SRC_INCR; break; default: @@ -173,6 +169,8 @@ static void s3c64xx_dma_fill_lli(struct s3c2410_dma_chan *chan, control1 = size >> chan->hw_width; /* size in no of xfers */ control0 |= PL080_CONTROL_PROT_SYS; /* always in priv. mode */ control0 |= PL080_CONTROL_TC_IRQ_EN; /* always fire IRQ */ + control0 |= (u32)chan->hw_width << PL080_CONTROL_DWIDTH_SHIFT; + control0 |= (u32)chan->hw_width << PL080_CONTROL_SWIDTH_SHIFT; lli->src_addr = src; lli->dst_addr = dst; -- cgit v1.2.3 From 9b08284bf22f438baa2d6b68015ff17ddb431a61 Mon Sep 17 00:00:00 2001 From: Jassi Brar Date: Thu, 5 Nov 2009 13:44:33 +0900 Subject: ARM: S3C64XX: DMA: Callback with correct buffer pointer buffdone callback should be called per buffer request with pointer to the latest serviced request. 'next' should point to the one next to currently active. Signed-off-by: Jassi Brar Signed-off-by: Ben Dooks --- arch/arm/plat-s3c64xx/dma.c | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/arm/plat-s3c64xx/dma.c b/arch/arm/plat-s3c64xx/dma.c index a94281bb84d..7d12eb8fa58 100644 --- a/arch/arm/plat-s3c64xx/dma.c +++ b/arch/arm/plat-s3c64xx/dma.c @@ -576,6 +576,7 @@ static irqreturn_t s3c64xx_dma_irq(int irq, void *pw) errstat = readl(dmac->regs + PL080_ERR_STATUS); for (offs = 0, bit = 1; offs < 8; offs++, bit <<= 1) { + struct s3c64xx_dma_buff *buff; if (!(errstat & bit) && !(tcstat & bit)) continue; @@ -591,7 +592,33 @@ static irqreturn_t s3c64xx_dma_irq(int irq, void *pw) if (errstat & bit) writel(bit, dmac->regs + PL080_ERR_CLEAR); - s3c64xx_dma_bufffdone(chan, chan->curr, res); + /* 'next' points to the buffer that is next to the + * currently active buffer. + * For CIRCULAR queues, 'next' will be same as 'curr' + * when 'end' is the active buffer. + */ + buff = chan->curr; + while (buff && buff != chan->next + && buff->next != chan->next) + buff = buff->next; + + if (!buff) + BUG(); + + if (buff == chan->next) + buff = chan->end; + + s3c64xx_dma_bufffdone(chan, buff, res); + + /* Update 'next' */ + buff = chan->next; + if (chan->next == chan->end) { + chan->next = chan->curr; + if (!(chan->flags & S3C2410_DMAF_CIRCULAR)) + chan->end = NULL; + } else { + chan->next = buff->next; + } } return IRQ_HANDLED; -- cgit v1.2.3 From 336b1a3181d81db85c0af3d0c18fe0a04b4d5126 Mon Sep 17 00:00:00 2001 From: Jassi Brar Date: Thu, 5 Nov 2009 13:44:39 +0900 Subject: ARM: S3C64XX: DMA: Free node for non-circular queues We need to free the buff and lli nodes if the buffer queue is not CIRCULAR. Signed-off-by: Jassi Brar Signed-off-by: Ben Dooks --- arch/arm/plat-s3c64xx/dma.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'arch') diff --git a/arch/arm/plat-s3c64xx/dma.c b/arch/arm/plat-s3c64xx/dma.c index 7d12eb8fa58..d554b936fcf 100644 --- a/arch/arm/plat-s3c64xx/dma.c +++ b/arch/arm/plat-s3c64xx/dma.c @@ -610,6 +610,12 @@ static irqreturn_t s3c64xx_dma_irq(int irq, void *pw) s3c64xx_dma_bufffdone(chan, buff, res); + /* Free the node and update curr, if non-circular queue */ + if (!(chan->flags & S3C2410_DMAF_CIRCULAR)) { + chan->curr = buff->next; + s3c64xx_dma_freebuff(buff); + } + /* Update 'next' */ buff = chan->next; if (chan->next == chan->end) { -- cgit v1.2.3