Hi, On 07/05/2019 9.09, Baolin Wang wrote: > When user try to request one DMA channel by __dma_request_channel(), it won't > validate if it is the correct DMA device to request, that will lead each DMA > engine driver to validate the correct device node in their filter function > if it is necessary. > > Thus we can add the matching device node validation in the DMA engine core, > to remove all of device node validation in the drivers.
I have picked this patch to my TI UDMA series and with __dma_request_channel() it works as expected - picking the channel from the correct DMA device. Tested-by: Peter Ujfalusi <[email protected]> > > Signed-off-by: Baolin Wang <[email protected]> > --- > drivers/dma/dmaengine.c | 10 ++++++++-- > drivers/dma/of-dma.c | 4 ++-- > include/linux/dmaengine.h | 12 ++++++++---- > 3 files changed, 18 insertions(+), 8 deletions(-) > > diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c > index 3a11b10..610080c 100644 > --- a/drivers/dma/dmaengine.c > +++ b/drivers/dma/dmaengine.c > @@ -641,11 +641,13 @@ struct dma_chan *dma_get_any_slave_channel(struct > dma_device *device) > * @mask: capabilities that the channel must satisfy > * @fn: optional callback to disposition available channels > * @fn_param: opaque parameter to pass to dma_filter_fn > + * @np: device node to look for DMA channels > * > * Returns pointer to appropriate DMA channel on success or NULL. > */ > struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask, > - dma_filter_fn fn, void *fn_param) > + dma_filter_fn fn, void *fn_param, > + struct device_node *np) > { > struct dma_device *device, *_d; > struct dma_chan *chan = NULL; > @@ -653,6 +655,10 @@ struct dma_chan *__dma_request_channel(const > dma_cap_mask_t *mask, > /* Find a channel */ > mutex_lock(&dma_list_mutex); > list_for_each_entry_safe(device, _d, &dma_device_list, global_node) { > + /* Finds a DMA controller with matching device node */ > + if (np && device->dev->of_node && np != device->dev->of_node) > + continue; > + > chan = find_candidate(device, mask, fn, fn_param); > if (!IS_ERR(chan)) > break; > @@ -769,7 +775,7 @@ struct dma_chan *dma_request_chan_by_mask(const > dma_cap_mask_t *mask) > if (!mask) > return ERR_PTR(-ENODEV); > > - chan = __dma_request_channel(mask, NULL, NULL); > + chan = __dma_request_channel(mask, NULL, NULL, NULL); > if (!chan) { > mutex_lock(&dma_list_mutex); > if (list_empty(&dma_device_list)) > diff --git a/drivers/dma/of-dma.c b/drivers/dma/of-dma.c > index 91fd395..6b43d04 100644 > --- a/drivers/dma/of-dma.c > +++ b/drivers/dma/of-dma.c > @@ -316,8 +316,8 @@ struct dma_chan *of_dma_simple_xlate(struct > of_phandle_args *dma_spec, > if (count != 1) > return NULL; > > - return dma_request_channel(info->dma_cap, info->filter_fn, > - &dma_spec->args[0]); > + return __dma_request_channel(&info->dma_cap, info->filter_fn, > + &dma_spec->args[0], dma_spec->np); > } > EXPORT_SYMBOL_GPL(of_dma_simple_xlate); > > diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h > index d49ec5c..504085b 100644 > --- a/include/linux/dmaengine.h > +++ b/include/linux/dmaengine.h > @@ -1314,7 +1314,8 @@ static inline enum dma_status > dma_async_is_complete(dma_cookie_t cookie, > enum dma_status dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx); > void dma_issue_pending_all(void); > struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask, > - dma_filter_fn fn, void *fn_param); > + dma_filter_fn fn, void *fn_param, > + struct device_node *np); > struct dma_chan *dma_request_slave_channel(struct device *dev, const char > *name); > > struct dma_chan *dma_request_chan(struct device *dev, const char *name); > @@ -1339,7 +1340,9 @@ static inline void dma_issue_pending_all(void) > { > } > static inline struct dma_chan *__dma_request_channel(const dma_cap_mask_t > *mask, > - dma_filter_fn fn, void *fn_param) > + dma_filter_fn fn, > + void *fn_param, > + struct device_node *np) > { > return NULL; > } > @@ -1411,7 +1414,8 @@ static inline int dmaengine_desc_free(struct > dma_async_tx_descriptor *desc) > 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); > -#define dma_request_channel(mask, x, y) __dma_request_channel(&(mask), x, y) > +#define dma_request_channel(mask, x, y) \ > + __dma_request_channel(&(mask), x, y, NULL) > #define dma_request_slave_channel_compat(mask, x, y, dev, name) \ > __dma_request_slave_channel_compat(&(mask), x, y, dev, name) > > @@ -1429,6 +1433,6 @@ static inline int dmaengine_desc_free(struct > dma_async_tx_descriptor *desc) > if (!fn || !fn_param) > return NULL; > > - return __dma_request_channel(mask, fn, fn_param); > + return __dma_request_channel(mask, fn, fn_param, NULL); > } > #endif /* DMAENGINE_H */ > - Péter Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
