0b5d87fd30
As usual, this patches were taken (and rebased) from https://github.com/raspberrypi/linux/commits/rpi-4.1.y Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com> SVN-Revision: 46853
173 lines
4.9 KiB
Diff
173 lines
4.9 KiB
Diff
From 4e62a443aa8ffecca7918db93329d8bd8210a92c Mon Sep 17 00:00:00 2001
|
|
From: Phil Elwell <phil@raspberrypi.org>
|
|
Date: Thu, 20 Aug 2015 13:50:18 +0100
|
|
Subject: [PATCH 165/171] bcm2708-dmaengine: Use more DMA channels (but not 12)
|
|
|
|
1) Only the bcm2708_fb drivers uses the legacy DMA API, and
|
|
it requires a BULK-capable channel, so all other types
|
|
(FAST, NORMAL and LITE) can be made available to the regular
|
|
DMA API.
|
|
|
|
2) DMA channels 11-14 share an interrupt. The driver can't
|
|
handle this, so don't use channels 12-14 (12 was used, probably
|
|
because it appears to have an interrupt, but in reality that
|
|
interrupt is for activity on ANY channel). This may explain
|
|
a lockup encountered when running out of DMA channels.
|
|
|
|
The combined effect of this patch is to leave 7 DMA channels
|
|
available + channel 0 for bcm2708_fb via the legacy API.
|
|
|
|
See: https://github.com/raspberrypi/linux/issues/1110
|
|
https://github.com/raspberrypi/linux/issues/1108
|
|
---
|
|
arch/arm/boot/dts/bcm2708_common.dtsi | 5 ++--
|
|
drivers/dma/bcm2708-dmaengine.c | 43 +++++++++++++++++++++++------------
|
|
2 files changed, 31 insertions(+), 17 deletions(-)
|
|
|
|
--- a/arch/arm/boot/dts/bcm2708_common.dtsi
|
|
+++ b/arch/arm/boot/dts/bcm2708_common.dtsi
|
|
@@ -59,11 +59,10 @@
|
|
<1 24>,
|
|
<1 25>,
|
|
<1 26>,
|
|
- <1 27>,
|
|
- <1 28>;
|
|
+ <1 27>;
|
|
|
|
#dma-cells = <1>;
|
|
- brcm,dma-channel-mask = <0x7f35>;
|
|
+ brcm,dma-channel-mask = <0x0f35>;
|
|
};
|
|
|
|
intc: interrupt-controller {
|
|
--- a/drivers/dma/bcm2708-dmaengine.c
|
|
+++ b/drivers/dma/bcm2708-dmaengine.c
|
|
@@ -184,7 +184,7 @@ static void vc_dmaman_init(struct vc_dma
|
|
}
|
|
|
|
static int vc_dmaman_chan_alloc(struct vc_dmaman *dmaman,
|
|
- unsigned preferred_feature_set)
|
|
+ unsigned required_feature_set)
|
|
{
|
|
u32 chans;
|
|
int chan = 0;
|
|
@@ -193,10 +193,8 @@ static int vc_dmaman_chan_alloc(struct v
|
|
chans = dmaman->chan_available;
|
|
for (feature = 0; feature < BCM_DMA_FEATURE_COUNT; feature++)
|
|
/* select the subset of available channels with the desired
|
|
- feature so long as some of the candidate channels have that
|
|
- feature */
|
|
- if ((preferred_feature_set & (1 << feature)) &&
|
|
- (chans & dmaman->has_feature[feature]))
|
|
+ features */
|
|
+ if (required_feature_set & (1 << feature))
|
|
chans &= dmaman->has_feature[feature];
|
|
|
|
if (!chans)
|
|
@@ -228,7 +226,7 @@ static int vc_dmaman_chan_free(struct vc
|
|
|
|
/* DMA Manager Monitor */
|
|
|
|
-extern int bcm_dma_chan_alloc(unsigned preferred_feature_set,
|
|
+extern int bcm_dma_chan_alloc(unsigned required_feature_set,
|
|
void __iomem **out_dma_base, int *out_dma_irq)
|
|
{
|
|
struct vc_dmaman *dmaman = g_dmaman;
|
|
@@ -240,7 +238,7 @@ extern int bcm_dma_chan_alloc(unsigned p
|
|
return -ENODEV;
|
|
|
|
mutex_lock(&dmaman->lock);
|
|
- chan = vc_dmaman_chan_alloc(dmaman, preferred_feature_set);
|
|
+ chan = vc_dmaman_chan_alloc(dmaman, required_feature_set);
|
|
if (chan < 0)
|
|
goto out;
|
|
|
|
@@ -442,6 +440,7 @@ static inline struct bcm2835_desc *to_bc
|
|
return container_of(t, struct bcm2835_desc, vd.tx);
|
|
}
|
|
|
|
+#if 0
|
|
static void dma_dumpregs(struct bcm2835_chan *c)
|
|
{
|
|
pr_debug("-------------DMA DUMPREGS-------------\n");
|
|
@@ -457,6 +456,7 @@ static void dma_dumpregs(struct bcm2835_
|
|
readl(c->chan_base + BCM2835_DMA_NEXTCB));
|
|
pr_debug("--------------------------------------\n");
|
|
}
|
|
+#endif
|
|
|
|
static void bcm2835_dma_desc_free(struct virt_dma_desc *vd)
|
|
{
|
|
@@ -862,6 +862,7 @@ static struct dma_async_tx_descriptor *b
|
|
uint32_t len = sg_dma_len(sgent);
|
|
|
|
for (j = 0; j < len; j += max_size) {
|
|
+ u32 waits;
|
|
struct bcm2835_dma_cb *control_block =
|
|
&d->control_block_base[i+splitct];
|
|
|
|
@@ -879,7 +880,7 @@ static struct dma_async_tx_descriptor *b
|
|
}
|
|
|
|
/* Common part */
|
|
- u32 waits = SDHCI_BCM_DMA_WAITS;
|
|
+ waits = SDHCI_BCM_DMA_WAITS;
|
|
if ((dma_debug >> 0) & 0x1f)
|
|
waits = (dma_debug >> 0) & 0x1f;
|
|
control_block->info |= BCM2835_DMA_WAITS(waits);
|
|
@@ -1074,6 +1075,14 @@ static int bcm2835_dma_probe(struct plat
|
|
int rc;
|
|
int i;
|
|
int irq;
|
|
+#ifdef CONFIG_DMA_BCM2708_LEGACY
|
|
+ static const u32 wanted_features[] = {
|
|
+ BCM_DMA_FEATURE_FAST,
|
|
+ BCM_DMA_FEATURE_NORMAL,
|
|
+ BCM_DMA_FEATURE_LITE
|
|
+ };
|
|
+ int j;
|
|
+#endif
|
|
|
|
|
|
if (!pdev->dev.dma_mask)
|
|
@@ -1120,20 +1129,24 @@ static int bcm2835_dma_probe(struct plat
|
|
|
|
platform_set_drvdata(pdev, od);
|
|
|
|
- for (i = 0; i < 5; i++) {
|
|
+ for (i = 0, j = 0; j < ARRAY_SIZE(wanted_features);) {
|
|
+
|
|
void __iomem *chan_base;
|
|
int chan_id;
|
|
|
|
- chan_id = bcm_dma_chan_alloc(BCM_DMA_FEATURE_LITE,
|
|
- &chan_base,
|
|
- &irq);
|
|
-
|
|
- if (chan_id < 0)
|
|
- break;
|
|
+ chan_id = bcm_dma_chan_alloc(wanted_features[j],
|
|
+ &chan_base,
|
|
+ &irq);
|
|
+
|
|
+ if (chan_id < 0) {
|
|
+ j++;
|
|
+ continue;
|
|
+ }
|
|
|
|
rc = bcm2708_dma_chan_init(od, chan_base, chan_id, irq);
|
|
if (rc)
|
|
goto err_no_dma;
|
|
+ i++;
|
|
}
|
|
|
|
if (pdev->dev.of_node) {
|
|
@@ -1146,6 +1159,8 @@ static int bcm2835_dma_probe(struct plat
|
|
}
|
|
}
|
|
|
|
+ dev_info(&pdev->dev, "Initialized %i DMA channels (+ 1 legacy)\n", i);
|
|
+
|
|
#else
|
|
rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
|
|
if (rc)
|