| Message ID | 1385494851-22640-1-git-send-email-swarren@wwwdotorg.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 8010dad55a0a |
| Headers | show |
On 11/26/2013 12:40 PM, Stephen Warren wrote: > From: Stephen Warren <swarren@nvidia.com> > > mmp_pdma.c implements a custom of_xlate() function that is 95% identical > to what Tegra will need. Create a function to implement the common part, > so everyone doesn't just cut/paste the implementation. > > Cc: Dan Williams <dan.j.williams@intel.com> > Cc: Vinod Koul <vinod.koul@intel.com> > Cc: Lars-Peter Clausen <lars@metafoo.de> > Cc: dmaengine@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Stephen Warren <swarren@nvidia.com> > --- > v3: > * Re-implemented the common code as dma_get_any_slave_channel(), in > dmaengine.c. This allows it to mutex_lock(&dma_list_mutex), and hence > avoid the retry loop. > * Rather than having the common code call out to a driver-provided > callback at the tail (which avoided drivers having to implement an > of_xlate function themselves), have drivers implement a custom > of_xlate() again, which mostly just calls the new > dma_get_any_slave_channel(), then does any extra custom work. > > v2: > * Squashed the conversion of mmp_pdma.c into the patch that added the > common implementation, so it's easier to see the whole conversion in > one go. > > This patch is a dependency for a series that reworks many of the Tegra > drivers. > > As such, it needs to go into a topic branch on its own, based directly > on 3.13-rc1. If the DMA maintainers ack the patches I'm happy to create > this topic branch myself and send a pull request to the DMA tree. Or the > patches can be applied to a topic branch by the DMA maintainers and I > will merge their topic branch into the Tegra rework branch that I > mentioned. > > Note that this patch is independant from the "dma: add channel request > API that supports deferred probe" which I just sent, so it could > (should?) be a different topic branch. Vinod, does this patch look OK to you? Are you able to stage it into a topic branch that I can pull into the Tegra tree as a dependency? -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Nov 26, 2013 at 12:40:51PM -0700, Stephen Warren wrote: > From: Stephen Warren <swarren@nvidia.com> > > mmp_pdma.c implements a custom of_xlate() function that is 95% identical > to what Tegra will need. Create a function to implement the common part, > so everyone doesn't just cut/paste the implementation. Applied, to topic/of -- ~Vinod -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 12/10/2013 05:22 AM, Vinod Koul wrote: > On Tue, Nov 26, 2013 at 12:40:51PM -0700, Stephen Warren wrote: >> From: Stephen Warren <swarren@nvidia.com> >> >> mmp_pdma.c implements a custom of_xlate() function that is 95% identical >> to what Tegra will need. Create a function to implement the common part, >> so everyone doesn't just cut/paste the implementation. > > Applied, to topic/of I assume this one also won't be rebased, so I can merge this into the Tegra tree as well? Thanks. -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index e17e9b22d85e..24095ff8a93b 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -535,6 +535,34 @@ struct dma_chan *dma_get_slave_channel(struct dma_chan *chan) } EXPORT_SYMBOL_GPL(dma_get_slave_channel); +struct dma_chan *dma_get_any_slave_channel(struct dma_device *device) +{ + dma_cap_mask_t mask; + struct dma_chan *chan; + int err; + + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + + /* lock against __dma_request_channel */ + mutex_lock(&dma_list_mutex); + + chan = private_candidate(&mask, device, NULL, NULL); + if (chan) { + err = dma_chan_get(chan); + if (err) { + pr_debug("%s: failed to get %s: (%d)\n", + __func__, dma_chan_name(chan), err); + chan = NULL; + } + } + + mutex_unlock(&dma_list_mutex); + + return chan; +} +EXPORT_SYMBOL_GPL(dma_get_any_slave_channel); + /** * __dma_request_channel - try to allocate an exclusive channel * @mask: capabilities that the channel must satisfy diff --git a/drivers/dma/mmp_pdma.c b/drivers/dma/mmp_pdma.c index dcb1e05149a7..2998f1bffac1 100644 --- a/drivers/dma/mmp_pdma.c +++ b/drivers/dma/mmp_pdma.c @@ -893,33 +893,17 @@ static struct dma_chan *mmp_pdma_dma_xlate(struct of_phandle_args *dma_spec, struct of_dma *ofdma) { struct mmp_pdma_device *d = ofdma->of_dma_data; - struct dma_chan *chan, *candidate; + struct dma_chan *chan; + struct mmp_pdma_chan *c; -retry: - candidate = NULL; - - /* walk the list of channels registered with the current instance and - * find one that is currently unused */ - list_for_each_entry(chan, &d->device.channels, device_node) - if (chan->client_count == 0) { - candidate = chan; - break; - } - - if (!candidate) + chan = dma_get_any_slave_channel(&d->device); + if (!chan) return NULL; - /* dma_get_slave_channel will return NULL if we lost a race between - * the lookup and the reservation */ - chan = dma_get_slave_channel(candidate); - - if (chan) { - struct mmp_pdma_chan *c = to_mmp_pdma_chan(chan); - c->drcmr = dma_spec->args[0]; - return chan; - } + c = to_mmp_pdma_chan(chan); + c->drcmr = dma_spec->args[0]; - goto retry; + return chan; } static int mmp_pdma_probe(struct platform_device *op) diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index ed92b30a02fd..bae1568416f8 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -1087,6 +1087,7 @@ int dma_async_device_register(struct dma_device *device); void dma_async_device_unregister(struct dma_device *device); void dma_run_dependencies(struct dma_async_tx_descriptor *tx); struct dma_chan *dma_get_slave_channel(struct dma_chan *chan); +struct dma_chan *dma_get_any_slave_channel(struct dma_device *device); struct dma_chan *net_dma_find_channel(void); #define dma_request_channel(mask, x, y) __dma_request_channel(&(mask), x, y) #define dma_request_slave_channel_compat(mask, x, y, dev, name) \