| Message ID | 20231011-b4-feature_hdma_mainline-v3-1-24ee0c979c6f@bootlin.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Fix support of dw-edma HDMA NATIVE IP in remote setup | expand |
On Wed, Oct 11, 2023 at 10:11:40AM +0200, Kory Maincent wrote: > The current check of ch_en enabled to know the maximum number of available > hardware channels is wrong as it check the number of ch_en register set > but all of them are unset at probe. This register is set at the > dw_hdma_v0_core_start function which is run lately before a DMA transfer. > > The HDMA IP have no way to know the number of hardware channels available > like the eDMA IP, then let set it to maximum channels and let the platform > set the right number of channels. > > Fixes: e74c39573d35 ("dmaengine: dw-edma: Add support for native HDMA") > Signed-off-by: Kory Maincent <kory.maincent@bootlin.com> > Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> So no news from Cai... I guess we can accept it as is then. Reviewed-by: Serge Semin <fancer.lancer@gmail.com> -Serge(y) > --- > > See the following thread mail that talk about this issue: > https://lore.kernel.org/lkml/20230607095832.6d6b1a73@kmaincent-XPS-13-7390/ > > Changes in v2: > - Add comment > > Changes in v3: > - Fix comment style. > --- > drivers/dma/dw-edma/dw-hdma-v0-core.c | 18 ++++++------------ > 1 file changed, 6 insertions(+), 12 deletions(-) > > diff --git a/drivers/dma/dw-edma/dw-hdma-v0-core.c b/drivers/dma/dw-edma/dw-hdma-v0-core.c > index 00b735a0202a..1f4cb7db5475 100644 > --- a/drivers/dma/dw-edma/dw-hdma-v0-core.c > +++ b/drivers/dma/dw-edma/dw-hdma-v0-core.c > @@ -65,18 +65,12 @@ static void dw_hdma_v0_core_off(struct dw_edma *dw) > > static u16 dw_hdma_v0_core_ch_count(struct dw_edma *dw, enum dw_edma_dir dir) > { > - u32 num_ch = 0; > - int id; > - > - for (id = 0; id < HDMA_V0_MAX_NR_CH; id++) { > - if (GET_CH_32(dw, id, dir, ch_en) & BIT(0)) > - num_ch++; > - } > - > - if (num_ch > HDMA_V0_MAX_NR_CH) > - num_ch = HDMA_V0_MAX_NR_CH; > - > - return (u16)num_ch; > + /* > + * The HDMA IP have no way to know the number of hardware channels > + * available, we set it to maximum channels and let the platform > + * set the right number of channels. > + */ > + return HDMA_V0_MAX_NR_CH; > } > > static enum dma_status dw_hdma_v0_core_ch_status(struct dw_edma_chan *chan) > > -- > 2.25.1 >
diff --git a/drivers/dma/dw-edma/dw-hdma-v0-core.c b/drivers/dma/dw-edma/dw-hdma-v0-core.c index 00b735a0202a..1f4cb7db5475 100644 --- a/drivers/dma/dw-edma/dw-hdma-v0-core.c +++ b/drivers/dma/dw-edma/dw-hdma-v0-core.c @@ -65,18 +65,12 @@ static void dw_hdma_v0_core_off(struct dw_edma *dw) static u16 dw_hdma_v0_core_ch_count(struct dw_edma *dw, enum dw_edma_dir dir) { - u32 num_ch = 0; - int id; - - for (id = 0; id < HDMA_V0_MAX_NR_CH; id++) { - if (GET_CH_32(dw, id, dir, ch_en) & BIT(0)) - num_ch++; - } - - if (num_ch > HDMA_V0_MAX_NR_CH) - num_ch = HDMA_V0_MAX_NR_CH; - - return (u16)num_ch; + /* + * The HDMA IP have no way to know the number of hardware channels + * available, we set it to maximum channels and let the platform + * set the right number of channels. + */ + return HDMA_V0_MAX_NR_CH; } static enum dma_status dw_hdma_v0_core_ch_status(struct dw_edma_chan *chan)
The current check of ch_en enabled to know the maximum number of available hardware channels is wrong as it check the number of ch_en register set but all of them are unset at probe. This register is set at the dw_hdma_v0_core_start function which is run lately before a DMA transfer. The HDMA IP have no way to know the number of hardware channels available like the eDMA IP, then let set it to maximum channels and let the platform set the right number of channels. Fixes: e74c39573d35 ("dmaengine: dw-edma: Add support for native HDMA") Signed-off-by: Kory Maincent <kory.maincent@bootlin.com> Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> --- See the following thread mail that talk about this issue: https://lore.kernel.org/lkml/20230607095832.6d6b1a73@kmaincent-XPS-13-7390/ Changes in v2: - Add comment Changes in v3: - Fix comment style. --- drivers/dma/dw-edma/dw-hdma-v0-core.c | 18 ++++++------------ 1 file changed, 6 insertions(+), 12 deletions(-)