Re: [PATCH RESEND v4] dmaengine: dw-edma: Enable HDMA 64R/W Channels

[Verma, Devendra]

On 25-Jun-26 21:26, Frank Li wrote:
> On Tue, Jun 23, 2026 at 04:56:47PM +0530, Devendra K Verma wrote:
> > As per 'Designware Cores PCI Express Controller Databook',
> > Section 7.1 - Overview, HDMA supports 64 Read and 64 Write
> > channels. Current controller driver supports up to 8 read and
> > write channels only. In order to utilize all the channels the
> > controller driver need to have the channel related structs
> > and variables as per the number of channels supported by IP.
> > Following changes are made to enable 64 Read / 64 Write
> > channel support:
> >
> >   o Defined HDMA specific macros to reflect the channel count.
> >   o The count of ll_regions and dt_regions in dw_edma_chip and
> >     dw_edma_pcie_data shall be in accordance to number of read
> >     and write channels.
> >   o In dw_edma_probe() configure the channels as per the channels
> >     of the IP used.
> >   o Changed mask types to u64 for higher channel counts.
> >
> > Signed-off-by: Devendra K Verma <devendra.verma@xxxxxxx>
> > ---
> ...
> > @@ -118,7 +129,8 @@ dw_hdma_v0_core_handle_int(struct dw_edma_irq *dw_irq, enum dw_edma_dir dir,
> >   	unsigned long total, pos, val;
> >   	irqreturn_t ret = IRQ_NONE;
> >   	struct dw_edma_chan *chan;
> > -	unsigned long off, mask;
> > +	unsigned long off;
> > +	u64 mask;
> >
> >   	if (dir == EDMA_DIR_WRITE) {
> >   		total = dw->wr_ch_cnt;
> > @@ -130,7 +142,11 @@ dw_hdma_v0_core_handle_int(struct dw_edma_irq *dw_irq, enum dw_edma_dir dir,
> >   		mask = dw_irq->rd_mask;
> >   	}
> >
> > -	for_each_set_bit(pos, &mask, total) {
> > +	while (mask) {
>
> can you use  DECLARE_BITMAP(status_mask, 64); and keep original for_each_set_bit()
> ref:
>
> https://lore.kernel.org/dmaengine/aj1JrufD1vIZH06s@lizhi-Precision-Tower-5810/T/#u
>
> Frank

Hi Frank, thank you for the suggestion!
This is also appreciation comment in the way you review and provide
example for the ease of reviewer and patch developers which helps
in speed up evaluation and implementation for that particular
suggestion.

I will push the changes in next review.

-Devendra