diff options
| author | Thomas Petazzoni <thomas.petazzoni@free-electrons.com> | 2017-05-05 12:57:48 +0300 |
|---|---|---|
| committer | Vinod Koul <vinod.koul@intel.com> | 2017-05-14 15:54:43 +0300 |
| commit | 44d5887a8bf1e86915c8ff647337cb138149da82 (patch) | |
| tree | 06c11d68ea2a2bd13fe6a88a23c5f3d62222c886 /drivers/dma | |
| parent | ab2c5f0a77fe49bdb6e307b397496373cb47d2c2 (diff) | |
| download | linux-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.c | 22 |
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); |