mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-16 07:35:14 +00:00
Avoid hw_desc array overrun in dw-axi-dmac
[ Upstream commit 333e11bf47
]
I have a use case where nr_buffers = 3 and in which each descriptor is composed by 3
segments, resulting in the DMA channel descs_allocated to be 9. Since axi_desc_put()
handles the hw_desc considering the descs_allocated, this scenario would result in a
kernel panic (hw_desc array will be overrun).
To fix this, the proposal is to add a new member to the axi_dma_desc structure,
where we keep the number of allocated hw_descs (axi_desc_alloc()) and use it in
axi_desc_put() to handle the hw_desc array correctly.
Additionally I propose to remove the axi_chan_start_first_queued() call after completing
the transfer, since it was identified that unbalance can occur (started descriptors can
be interrupted and transfer ignored due to DMA channel not being enabled).
Signed-off-by: Joao Pinto <jpinto@synopsys.com>
Link: https://lore.kernel.org/r/1711536564-12919-1-git-send-email-jpinto@synopsys.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
parent
10132ccf99
commit
e151ae1ee0
2 changed files with 3 additions and 4 deletions
|
@ -256,6 +256,7 @@ static struct axi_dma_desc *axi_desc_alloc(u32 num)
|
||||||
kfree(desc);
|
kfree(desc);
|
||||||
return NULL;
|
return NULL;
|
||||||
}
|
}
|
||||||
|
desc->nr_hw_descs = num;
|
||||||
|
|
||||||
return desc;
|
return desc;
|
||||||
}
|
}
|
||||||
|
@ -282,7 +283,7 @@ static struct axi_dma_lli *axi_desc_get(struct axi_dma_chan *chan,
|
||||||
static void axi_desc_put(struct axi_dma_desc *desc)
|
static void axi_desc_put(struct axi_dma_desc *desc)
|
||||||
{
|
{
|
||||||
struct axi_dma_chan *chan = desc->chan;
|
struct axi_dma_chan *chan = desc->chan;
|
||||||
int count = atomic_read(&chan->descs_allocated);
|
int count = desc->nr_hw_descs;
|
||||||
struct axi_dma_hw_desc *hw_desc;
|
struct axi_dma_hw_desc *hw_desc;
|
||||||
int descs_put;
|
int descs_put;
|
||||||
|
|
||||||
|
@ -1093,9 +1094,6 @@ static void axi_chan_block_xfer_complete(struct axi_dma_chan *chan)
|
||||||
/* Remove the completed descriptor from issued list before completing */
|
/* Remove the completed descriptor from issued list before completing */
|
||||||
list_del(&vd->node);
|
list_del(&vd->node);
|
||||||
vchan_cookie_complete(vd);
|
vchan_cookie_complete(vd);
|
||||||
|
|
||||||
/* Submit queued descriptors after processing the completed ones */
|
|
||||||
axi_chan_start_first_queued(chan);
|
|
||||||
}
|
}
|
||||||
|
|
||||||
out:
|
out:
|
||||||
|
|
|
@ -104,6 +104,7 @@ struct axi_dma_desc {
|
||||||
u32 completed_blocks;
|
u32 completed_blocks;
|
||||||
u32 length;
|
u32 length;
|
||||||
u32 period_len;
|
u32 period_len;
|
||||||
|
u32 nr_hw_descs;
|
||||||
};
|
};
|
||||||
|
|
||||||
struct axi_dma_chan_config {
|
struct axi_dma_chan_config {
|
||||||
|
|
Loading…
Reference in a new issue