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authorThomas Petazzoni <thomas.petazzoni@free-electrons.com>2017-05-05 12:57:48 +0300
committerVinod Koul <vinod.koul@intel.com>2017-05-14 15:54:43 +0300
commit44d5887a8bf1e86915c8ff647337cb138149da82 (patch)
tree06c11d68ea2a2bd13fe6a88a23c5f3d62222c886 /drivers/dma
parentab2c5f0a77fe49bdb6e307b397496373cb47d2c2 (diff)
downloadlinux-44d5887a8bf1e86915c8ff647337cb138149da82.tar.xz
dmaengine: mv_xor_v2: fix tx_submit() implementation
The mv_xor_v2_tx_submit() gets the next available HW descriptor by calling mv_xor_v2_get_desq_write_ptr(), which reads a HW register telling the next available HW descriptor. This was working fine when HW descriptors were issued for processing directly in tx_submit(). However, as part of the review process of the driver, a change was requested to move the actual kick-off of HW descriptors processing to ->issue_pending(). Due to this, reading the HW register to know the next available HW descriptor no longer works. So instead of using this HW register, we implemented a software index pointing to the next available HW descriptor. Fixes: 19a340b1a820 ("dmaengine: mv_xor_v2: new driver") Cc: <stable@vger.kernel.org> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/mv_xor_v2.c22
1 files changed, 5 insertions, 17 deletions
diff --git a/drivers/dma/mv_xor_v2.c b/drivers/dma/mv_xor_v2.c
index 211b8c0e3cfb..4684eceea759 100644
--- a/drivers/dma/mv_xor_v2.c
+++ b/drivers/dma/mv_xor_v2.c
@@ -161,6 +161,7 @@ struct mv_xor_v2_device {
struct mv_xor_v2_sw_desc *sw_desq;
int desc_size;
unsigned int npendings;
+ unsigned int hw_queue_idx;
};
/**
@@ -214,18 +215,6 @@ static void mv_xor_v2_set_data_buffers(struct mv_xor_v2_device *xor_dev,
}
/*
- * Return the next available index in the DESQ.
- */
-static int mv_xor_v2_get_desq_write_ptr(struct mv_xor_v2_device *xor_dev)
-{
- /* read the index for the next available descriptor in the DESQ */
- u32 reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_ALLOC_OFF);
-
- return ((reg >> MV_XOR_V2_DMA_DESQ_ALLOC_WRPTR_SHIFT)
- & MV_XOR_V2_DMA_DESQ_ALLOC_WRPTR_MASK);
-}
-
-/*
* notify the engine of new descriptors, and update the available index.
*/
static void mv_xor_v2_add_desc_to_desq(struct mv_xor_v2_device *xor_dev,
@@ -306,7 +295,6 @@ static irqreturn_t mv_xor_v2_interrupt_handler(int irq, void *data)
static dma_cookie_t
mv_xor_v2_tx_submit(struct dma_async_tx_descriptor *tx)
{
- int desq_ptr;
void *dest_hw_desc;
dma_cookie_t cookie;
struct mv_xor_v2_sw_desc *sw_desc =
@@ -322,15 +310,15 @@ mv_xor_v2_tx_submit(struct dma_async_tx_descriptor *tx)
spin_lock_bh(&xor_dev->lock);
cookie = dma_cookie_assign(tx);
- /* get the next available slot in the DESQ */
- desq_ptr = mv_xor_v2_get_desq_write_ptr(xor_dev);
-
/* copy the HW descriptor from the SW descriptor to the DESQ */
- dest_hw_desc = xor_dev->hw_desq_virt + desq_ptr;
+ dest_hw_desc = xor_dev->hw_desq_virt + xor_dev->hw_queue_idx;
memcpy(dest_hw_desc, &sw_desc->hw_desc, xor_dev->desc_size);
xor_dev->npendings++;
+ xor_dev->hw_queue_idx++;
+ if (xor_dev->hw_queue_idx >= MV_XOR_V2_DESC_NUM)
+ xor_dev->hw_queue_idx = 0;
spin_unlock_bh(&xor_dev->lock);