public inbox for linux-arm-kernel@lists.infradead.org 
 help / color / mirror / Atom feed
From: vinod.koul@intel•com (Vinod Koul)
To: linux-arm-kernel@lists•infradead.org
Subject: [RFC PATCH v2 01/12] dmaengine: PL08x: Refactor pl08x_getbytes_chan() to lower indentation
Date: Tue, 25 Jun 2013 20:46:12 +0530	[thread overview]
Message-ID: <20130625151612.GO23141@intel.com> (raw)
In-Reply-To: <1371933764-24875-2-git-send-email-tomasz.figa@gmail.com>

On Sat, Jun 22, 2013 at 10:42:33PM +0200, Tomasz Figa wrote:
> Further patch will introduce support for PL080S, which requires some
> things to be done conditionally, thus increasing indentation level of
> some functions even more.
> 
> This patch reduces indentation level of pl08x_getbytes_chan() function
> by inverting several conditions and returning from function wherever
> possible.
> 
> Signed-off-by: Tomasz Figa <tomasz.figa@gmail•com>
> ---
>  drivers/dma/amba-pl08x.c | 53 ++++++++++++++++++++++++++----------------------
>  1 file changed, 29 insertions(+), 24 deletions(-)
> 
> diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
> index 06fe45c..6a12392 100644
> --- a/drivers/dma/amba-pl08x.c
> +++ b/drivers/dma/amba-pl08x.c
> @@ -469,47 +469,52 @@ static inline u32 get_bytes_in_cctl(u32 cctl)
>  /* The channel should be paused when calling this */
>  static u32 pl08x_getbytes_chan(struct pl08x_dma_chan *plchan)
>  {
> +	struct pl08x_lli *llis_va;
>  	struct pl08x_phy_chan *ch;
> +	dma_addr_t llis_bus;
>  	struct pl08x_txd *txd;
> -	size_t bytes = 0;
> +	size_t bytes;
> +	int index;
> +	u32 clli;
>  
>  	ch = plchan->phychan;
>  	txd = plchan->at;
>  
> +	if (!ch || !txd)
> +		return 0;
shouldnt this be err return

> +
>  	/*
>  	 * Follow the LLIs to get the number of remaining
>  	 * bytes in the currently active transaction.
>  	 */
> -	if (ch && txd) {
> -		u32 clli = readl(ch->base + PL080_CH_LLI) & ~PL080_LLI_LM_AHB2;
> +	clli = readl(ch->base + PL080_CH_LLI) & ~PL080_LLI_LM_AHB2;
>  
> -		/* First get the remaining bytes in the active transfer */
> -		bytes = get_bytes_in_cctl(readl(ch->base + PL080_CH_CONTROL));
> +	/* First get the remaining bytes in the active transfer */
> +	bytes = get_bytes_in_cctl(readl(ch->base + PL080_CH_CONTROL));
>  
> -		if (clli) {
> -			struct pl08x_lli *llis_va = txd->llis_va;
> -			dma_addr_t llis_bus = txd->llis_bus;
> -			int index;
> +	if (!clli)
> +		return bytes;
>  
> -			BUG_ON(clli < llis_bus || clli >= llis_bus +
> +	llis_va = txd->llis_va;
> +	llis_bus = txd->llis_bus;
> +
> +	BUG_ON(clli < llis_bus || clli >= llis_bus +
>  				sizeof(struct pl08x_lli) * MAX_NUM_TSFR_LLIS);
IMO BUG_ON is too much for this. Perhaps returning error and logging error would
be okay

--
~Vinod

  parent reply	other threads:[~2013-06-25 15:16 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-06-22 20:42 [RFC PATCH v2 00/12] ARM: s3c64xx: Let amba-pl08x driver handle DMA Tomasz Figa
2013-06-22 20:42 ` [RFC PATCH v2 01/12] dmaengine: PL08x: Refactor pl08x_getbytes_chan() to lower indentation Tomasz Figa
2013-06-24 22:09   ` Linus Walleij
2013-06-25 15:16   ` Vinod Koul [this message]
2013-06-25 18:30     ` Russell King - ARM Linux
2013-06-22 20:42 ` [RFC PATCH v2 02/12] dmaengine: PL08x: Add support for different offset of CONFIG register Tomasz Figa
2013-06-24 22:11   ` Linus Walleij
2013-06-25 15:34   ` Vinod Koul
2013-06-22 20:42 ` [RFC PATCH v2 03/12] dmaengine: PL08x: Rework LLI handling to be less fragile Tomasz Figa
2013-06-24 22:23   ` Linus Walleij
2013-06-26 22:04     ` Tomasz Figa
2013-06-27  9:31       ` Linus Walleij
2013-06-22 20:42 ` [RFC PATCH v2 04/12] dmaengine: PL08x: Add support for PL080S variant Tomasz Figa
2013-06-24 22:26   ` Linus Walleij
2013-06-22 20:42 ` [RFC PATCH v2 05/12] dmaengine: PL08x: Add support for different maximum transfer size Tomasz Figa
2013-06-24 22:27   ` Linus Walleij
2013-06-25 16:10   ` Vinod Koul
2013-06-22 20:42 ` [RFC PATCH v2 06/12] dmaengine: PL08x: Fix reading the byte count in cctl Tomasz Figa
2013-06-24 22:28   ` Linus Walleij
2013-06-22 20:42 ` [RFC PATCH v2 07/12] dmaengine: PL08x: Add cyclic transfer support Tomasz Figa
2013-06-24 22:33   ` Linus Walleij
2013-06-22 20:42 ` [RFC PATCH v2 08/12] ASoC: Samsung: Do not queue cyclic buffers multiple times Tomasz Figa
2013-06-24 22:35   ` Linus Walleij
2013-06-22 20:42 ` [RFC PATCH v2 09/12] clk: samsung: s3c64xx: Add aliases for DMA clocks Tomasz Figa
2013-06-24 22:38   ` Linus Walleij
2013-06-25  5:30     ` Tomasz Figa
2013-06-22 20:42 ` [RFC PATCH v2 10/12] spi: s3c64xx: Do not require legacy DMA API in case of S3C64XX Tomasz Figa
2013-06-22 20:42 ` [RFC PATCH v2 11/12] ASoC: Samsung: " Tomasz Figa
2013-06-22 20:42 ` [RFC PATCH v2 12/12] ARM: s3c64xx: Add support for DMA using generic amba-pl08x driver Tomasz Figa
2013-06-25 10:28 ` [RFC PATCH v2 00/12] ARM: s3c64xx: Let amba-pl08x driver handle DMA Mark Brown
2013-06-25 11:22   ` Tomasz Figa
2013-06-25 15:38     ` Mark Brown
2013-06-25 15:44       ` Tomasz Figa

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20130625151612.GO23141@intel.com \
    --to=vinod.koul@intel$(echo .)com \
    --cc=linux-arm-kernel@lists$(echo .)infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox