From: Qiang Liu <[email protected]>
Add memory copy self test when probe device, fsl-dma will be disabled
if self test failed.
Cc: Dan Williams <[email protected]>
Cc: Vinod Koul <[email protected]>
Cc: Li Yang <[email protected]>
Cc: Ira W. Snyder <[email protected]>
Signed-off-by: Qiang Liu <[email protected]>
---
drivers/dma/fsldma.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 83 insertions(+), 0 deletions(-)
diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c
index 6fc22eb..5e0b162 100644
--- a/drivers/dma/fsldma.c
+++ b/drivers/dma/fsldma.c
@@ -1277,6 +1277,82 @@ out_unwind:
return ret;
}
+/*
+ * Perform a transaction to verify the HW works.
+ */
+#define FSL_DMA_TEST_SIZE 2000
+
+static int __devinit fsl_dma_memcpy_self_test(struct fsldma_device *device)
+{
+ int i;
+ void *src, *dest;
+ dma_addr_t src_dma, dest_dma;
+ struct dma_chan *dma_chan;
+ dma_cookie_t cookie;
+ struct dma_async_tx_descriptor *tx;
+ int err = 0;
+ struct fsldma_chan *chan;
+
+ src = kmalloc(sizeof(u8) * FSL_DMA_TEST_SIZE, GFP_KERNEL);
+ if (!src)
+ return -ENOMEM;
+
+ dest = kzalloc(sizeof(u8) * FSL_DMA_TEST_SIZE, GFP_KERNEL);
+ if (!dest) {
+ kfree(src);
+ return -ENOMEM;
+ }
+
+ /* Fill in src buffer */
+ for (i = 0; i < FSL_DMA_TEST_SIZE; i++)
+ ((u8 *) src)[i] = (u8)i;
+
+ /* Start copy, using first DMA channel */
+ dma_chan = container_of(device->common.channels.next,
+ struct dma_chan, device_node);
+ if (fsl_dma_alloc_chan_resources(dma_chan) < 1) {
+ err = -ENODEV;
+ goto out;
+ }
+
+ chan = to_fsl_chan(dma_chan);
+ dest_dma = dma_map_single(chan->common.device->dev, dest,
+ FSL_DMA_TEST_SIZE, DMA_FROM_DEVICE);
+
+ src_dma = dma_map_single(chan->common.device->dev, src,
+ FSL_DMA_TEST_SIZE, DMA_TO_DEVICE);
+
+ tx = fsl_dma_prep_memcpy(dma_chan, dest_dma, src_dma, FSL_DMA_TEST_SIZE,
+ DMA_COMPL_SKIP_DEST_UNMAP | DMA_COMPL_SRC_UNMAP_SINGLE);
+ cookie = fsl_dma_tx_submit(tx);
+ fsl_dma_memcpy_issue_pending(dma_chan);
+ async_tx_ack(tx);
+ msleep(1);
+
+ if (fsl_tx_status(dma_chan, cookie, NULL) != DMA_SUCCESS) {
+ dev_printk(KERN_ERR, dma_chan->device->dev,
+ "Self-test copy timed out, disabling\n");
+ err = -ENODEV;
+ goto free_resources;
+ }
+
+ dma_sync_single_for_cpu(device->dev, dest_dma,
+ FSL_DMA_TEST_SIZE, DMA_FROM_DEVICE);
+ if (memcmp(src, dest, FSL_DMA_TEST_SIZE)) {
+ dev_printk(KERN_ERR, dma_chan->device->dev,
+ "Self-test copy failed compare, disabling\n");
+ err = -ENODEV;
+ goto free_resources;
+ }
+
+free_resources:
+ fsl_dma_free_chan_resources(dma_chan);
+out:
+ kfree(src);
+ kfree(dest);
+ return err;
+}
+
/*----------------------------------------------------------------------------*/
/* OpenFirmware Subsystem */
/*----------------------------------------------------------------------------*/
@@ -1461,6 +1537,13 @@ static int __devinit fsldma_of_probe(struct platform_device *op)
goto out_free_fdev;
}
+ if (dma_has_cap(DMA_MEMCPY, fdev->common.cap_mask)) {
+ err = fsl_dma_memcpy_self_test(fdev);
+ printk(KERN_INFO "FSL-DMA Channel memcpy self test returned %d\n", err);
+ if (err)
+ goto out_free_fdev;
+ }
+
dma_async_device_register(&fdev->common);
return 0;
--
1.7.5.1
[email protected] wrote:
>
> Add memory copy self test when probe device, fsl-dma will be disabled
> if self test failed.
Is this a real problem that can occur? The DMA driver used to have a
self-test, but I removed it a long time ago because it was pointless. I
don't see why we need to add another one back in.
--
Timur Tabi
Linux kernel developer at Freescale
On Mon, Jul 30, 2012 at 12:48:41PM -0500, Timur Tabi wrote:
> [email protected] wrote:
> >
> > Add memory copy self test when probe device, fsl-dma will be disabled
> > if self test failed.
>
> Is this a real problem that can occur? The DMA driver used to have a
> self-test, but I removed it a long time ago because it was pointless. I
> don't see why we need to add another one back in.
>
> --
> Timur Tabi
> Linux kernel developer at Freescale
>
I made a comment that a test suite for the async_tx API would be very
helpful in diagnosing similar problems in this and other DMA drivers.
Something standalone, similar to the drivers/dma/dmatest.c driver, using
the async_tx API.
I think this was misinterpreted into me asking that the driver have a
built-in self test.
Ira
> -----Original Message-----
> From: [email protected] [mailto:linux-crypto-
> [email protected]] On Behalf Of Ira W. Snyder
> Sent: Tuesday, July 31, 2012 2:33 AM
> To: Tabi Timur-B04825
> Cc: Liu Qiang-B32616; [email protected]; linuxppc-
> [email protected]; Vinod Koul; [email protected]; Dan
> Williams; Li Yang-R58472; [email protected]
> Subject: Re: [linuxppc-release] [PATCH v4 7/7] fsl-dma: add memcpy self
> test interface
>
> On Mon, Jul 30, 2012 at 12:48:41PM -0500, Timur Tabi wrote:
> > [email protected] wrote:
> > >
> > > Add memory copy self test when probe device, fsl-dma will be disabled
> > > if self test failed.
> >
> > Is this a real problem that can occur? The DMA driver used to have a
> > self-test, but I removed it a long time ago because it was pointless.
> I
> > don't see why we need to add another one back in.
> >
> > --
> > Timur Tabi
> > Linux kernel developer at Freescale
> >
>
> I made a comment that a test suite for the async_tx API would be very
> helpful in diagnosing similar problems in this and other DMA drivers.
> Something standalone, similar to the drivers/dma/dmatest.c driver, using
> the async_tx API.
>
> I think this was misinterpreted into me asking that the driver have a
> built-in self test.
I will drop it in next version. Thanks.
>
> Ira
> --
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