[PATCH 10/13] crypto: omap-sham - Support for deferred probing when requesting DMA channel

From: Peter Ujfalusi
Date: Tue May 26 2015 - 09:30:20 EST


Switch to use ma_request_slave_channel_compat_reason() to request the DMA
channel. Only fall back to polling mode if the error code returned is not
-EPROBE_DEFER, otherwise return from the probe with the -EPROBE_DEFER.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
CC: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
CC: David S. Miller <davem@xxxxxxxxxxxxx>
CC: Lokesh Vutla <lokeshvutla@xxxxxx>
---
drivers/crypto/omap-sham.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/crypto/omap-sham.c b/drivers/crypto/omap-sham.c
index b2024c95a3cf..66bae8288741 100644
--- a/drivers/crypto/omap-sham.c
+++ b/drivers/crypto/omap-sham.c
@@ -1946,9 +1946,14 @@ static int omap_sham_probe(struct platform_device *pdev)
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);

- dd->dma_lch = dma_request_slave_channel_compat(mask, omap_dma_filter_fn,
- &dd->dma, dev, "rx");
- if (!dd->dma_lch) {
+ dd->dma_lch = dma_request_slave_channel_compat_reason(mask,
+ omap_dma_filter_fn,
+ &dd->dma, dev, "rx");
+ if (IS_ERR(dd->dma_lch)) {
+ err = PTR_ERR(dd->dma_lch);
+ if (err == -EPROBE_DEFER)
+ goto data_err;
+
dd->polling_mode = 1;
dev_dbg(dev, "using polling mode instead of dma\n");
}
@@ -1995,7 +2000,7 @@ err_algs:
&dd->pdata->algs_info[i].algs_list[j]);
err_pm:
pm_runtime_disable(dev);
- if (dd->dma_lch)
+ if (!dd->polling_mode)
dma_release_channel(dd->dma_lch);
data_err:
dev_err(dev, "initialization failed.\n");
@@ -2021,7 +2026,7 @@ static int omap_sham_remove(struct platform_device *pdev)
tasklet_kill(&dd->done_task);
pm_runtime_disable(&pdev->dev);

- if (dd->dma_lch)
+ if (!dd->polling_mode)
dma_release_channel(dd->dma_lch);

return 0;
--
2.3.5

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