Re: [PATCH v3 11/15] dmaengine: sh: rz-dmac: Add cyclic DMA support

[Claudiu Beznea]

Hi, Biju,

On 4/7/26 17:36, Biju Das wrote:
> Hi Claudiu,
>
> Thanks for the patch.
>
> > -----Original Message-----
> > From: Claudiu <claudiu.beznea@xxxxxxxxx>
> > Sent: 07 April 2026 14:35
> > Subject: [PATCH v3 11/15] dmaengine: sh: rz-dmac: Add cyclic DMA support
> >
> > From: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
> >
> > Add cyclic DMA support to the RZ DMAC driver. A per-channel status bit is introduced to mark cyclic
> > channels and is set during the DMA prepare callback. The IRQ handler checks this status bit and calls
> > vchan_cyclic_callback() accordingly.
> >
> > Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
> > ---
> >
> > Changes in v3:
> > - updated rz_dmac_lmdesc_recycle() to restore the lmdesc->nxla
> > - in rz_dmac_prepare_descs_for_cyclic() update directly the
> >    desc->start_lmdesc with the descriptor pointer insted of the
> >    descriptor address
> > - used rz_dmac_lmdesc_addr() to compute the descritor address
> > - set channel->status = 0 in rz_dmac_free_chan_resources()
> > - in rz_dmac_prep_dma_cyclic() check for invalid periods or buffer len
> >    and limit the critical area protected by spinlock
> > - set channel->status = 0 in rz_dmac_terminate_all()
> > - updated rz_dmac_calculate_residue_bytes_in_vd() to use
> >    rz_dmac_lmdesc_addr()
> > - dropped goto in rz_dmac_irq_handler_thread() as it is not needed
> >    anymore; dropped also the local variable desc
> >
> > Changes in v2:
> > - none
> >
> >   drivers/dma/sh/rz-dmac.c | 144 +++++++++++++++++++++++++++++++++++++--
> >   1 file changed, 138 insertions(+), 6 deletions(-)

[ ... ]

> > @@ -500,6 +562,8 @@ static void rz_dmac_free_chan_resources(struct dma_chan *chan)
> >   		channel->mid_rid = -EINVAL;
> >   	}
> >
> > +	channel->status = 0;
> > +
> >   	spin_unlock_irqrestore(&channel->vc.lock, flags);
>
> Maybe create a patch to convert all the spin_{lock,unlock} with guard()
> in this driver.

This series already has to many patches and I want to keep only what is 
necessary for the cyclic support. My plan is to do the guard conversion after 
cyclic support gets merged.

Thank you,
Claudiu