Re: [PATCH 15/32] dmaengine: ste_dma40: Separate Logical GlobalInterrupt Mask (GIM) unmasking

From: Linus Walleij
Date: Thu Apr 25 2013 - 07:00:13 EST

On Thu, Apr 18, 2013 at 12:11 PM, Lee Jones <lee.jones@xxxxxxxxxx> wrote:

> During the initial setup of a logical channel, it is necessary to unmask
> the GIM in order to receive generated terminal count and error interrupts.
> We're separating out this required code so it will be possible to move
> the remaining code in d40_phy_cfg(), which is mostly runtime configuration
> into the runtime_config() routine.
> Cc: Vinod Koul <vinod.koul@xxxxxxxxx>
> Cc: Dan Williams <djbw@xxxxxx>
> Cc: Per Forlin <per.forlin@xxxxxxxxxxxxxx>
> Cc: Rabin Vincent <rabin@xxxxxx>
> Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>

This commit message needs to reflect the fact that you've observed
that one argument to the d40_phy_cfg() is hardcoded to false in the
runtime config, and that is why we can sink the use into

> @@ -2456,6 +2456,9 @@ static int d40_alloc_chan_resources(struct dma_chan *chan)
> }
> + if (chan_is_logical(d40c))
> + d40_log_gim_unmask(&d40c->src_def_cfg, &d40c->dst_def_cfg);

The clause right above is already a if (chan_is_logical(c)).
Just insert the function call into that clause.

> +void d40_log_gim_unmask(u32 *src_cfg, u32 *dst_cfg) {
> +
> + *src_cfg |= 1 << D40_SREG_CFG_LOG_GIM_POS;
> + *dst_cfg |= 1 << D40_SREG_CFG_LOG_GIM_POS;
> +}

Why create a separate function with two lines which is just called from
one single place?

Just sink this into the d40_alloc_chan_resources() function like that:

if (logical) {
*d40c->src_def_cfg |= 1 << D40_SREG_CFG_LOG_GIM_POS;
*d40c->dst_def_cfg |= 1 << D40_SREG_CFG_LOG_GIM_POS;

No need for a separate function and a separate header.

> /* Sets up SRC and DST CFG register for both logical and physical channels */
> void d40_phy_cfg(struct stedma40_chan_cfg *cfg,
> u32 *src_cfg, u32 *dst_cfg, bool is_log)

Take this opportunity to:

(A) delete the argument is_log since it has no use whatsoever after this.
Why pass it at all!

(B) De-indent the if (!is_log) clause... as a natural consequence.

Linus Walleij
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