+++ /dev/null
-From 08746a98cb4867e704bb799506301ca7200d78fa Mon Sep 17 00:00:00 2001
-From: Phil Elwell <phil@raspberrypi.org>
-Date: Thu, 20 Aug 2015 13:50:18 +0100
-Subject: [PATCH 163/222] 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)
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