Re: [PATCH v5 06/17] dmaengine: sh: rz-dmac: Save the start LM descriptor

[Claudiu Beznea <claudiu.beznea@kernel.org>]

Hi, Frank,

On 5/12/26 23:48, Frank Li wrote:
> On Tue, May 12, 2026 at 03:12:07PM +0300, Claudiu Beznea wrote:
>> Save the start LM descriptor to avoid looping through the entire
> 
> where the looping you try to avoid?

Here: https://elixir.bootlin.com/linux/v7.1-rc3/source/drivers/dma/sh/rz-dmac.c#L701

The point was to avoid starting from the head pointer and use directly the 
descriptor of interests:

-static u32 rz_dmac_calculate_residue_bytes_in_vd(struct rz_dmac_chan *channel, 
u32 crla)
+static u32 rz_dmac_calculate_residue_bytes_in_vd(struct rz_dmac_chan *channel,
+						 struct rz_dmac_desc *desc, u32 crla)
  {
-	struct rz_lmdesc *lmdesc = channel->lmdesc.head;
+	struct rz_lmdesc *lmdesc = desc->start_lmdesc;

Maybe "loop" was not the right word to use in the patch description. I'll adjust it.

-- 
Thank you,
Claudiu