Re: [PATCH 2/3] k3dma: add support to reserved minimum channels
From: Vinod <vkoul@kernel.org>
Date: 2018-06-28 06:02:52
Also in:
dmaengine, lkml
On 22-06-18, 11:24, Guodong Xu wrote:
From: Li Yu <redacted> On k3 series of SoC, DMA controller reserves some channels for other on-chip coprocessors. By adding support to dma_min_chan, kernel will not be able to use these reserved channels. One example is on Hi3660 platform, channel 0 is reserved to lpm3. Please also refer to Documentation/devicetree/bindings/dma/k3dma.txt
and if some other platform has channel X marked for co-processor, maybe a last channel or something in middle, how will this work then? I am thinking this should be a mask, rather than min.
quoted hunk ↗ jump to hunk
Signed-off-by: Li Yu <redacted> Signed-off-by: Guodong Xu <redacted> --- drivers/dma/k3dma.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-)diff --git a/drivers/dma/k3dma.c b/drivers/dma/k3dma.c index fa31cccbe04f..13cec12742e3 100644 --- a/drivers/dma/k3dma.c +++ b/drivers/dma/k3dma.c@@ -113,6 +113,7 @@ struct k3_dma_dev { struct dma_pool *pool; u32 dma_channels; u32 dma_requests; + u32 dma_min_chan; unsigned int irq; };@@ -309,7 +310,7 @@ static void k3_dma_tasklet(unsigned long arg) /* check new channel request in d->chan_pending */ spin_lock_irq(&d->lock); - for (pch = 0; pch < d->dma_channels; pch++) { + for (pch = d->dma_min_chan; pch < d->dma_channels; pch++) { p = &d->phy[pch]; if (p->vchan == NULL && !list_empty(&d->chan_pending)) {@@ -326,7 +327,7 @@ static void k3_dma_tasklet(unsigned long arg) } spin_unlock_irq(&d->lock); - for (pch = 0; pch < d->dma_channels; pch++) { + for (pch = d->dma_min_chan; pch < d->dma_channels; pch++) { if (pch_alloc & (1 << pch)) { p = &d->phy[pch]; c = p->vchan;@@ -825,6 +826,8 @@ static int k3_dma_probe(struct platform_device *op) "dma-channels", &d->dma_channels); of_property_read_u32((&op->dev)->of_node, "dma-requests", &d->dma_requests); + of_property_read_u32((&op->dev)->of_node, + "dma-min-chan", &d->dma_min_chan); } d->clk = devm_clk_get(&op->dev, NULL);@@ -848,12 +851,12 @@ static int k3_dma_probe(struct platform_device *op) return -ENOMEM; /* init phy channel */ - d->phy = devm_kcalloc(&op->dev, - d->dma_channels, sizeof(struct k3_dma_phy), GFP_KERNEL); + d->phy = devm_kcalloc(&op->dev, (d->dma_channels - d->dma_min_chan), + sizeof(struct k3_dma_phy), GFP_KERNEL); if (d->phy == NULL) return -ENOMEM; - for (i = 0; i < d->dma_channels; i++) { + for (i = d->dma_min_chan; i < d->dma_channels; i++) { struct k3_dma_phy *p = &d->phy[i]; p->idx = i;-- 2.17.1
-- ~Vinod