[PATCH 1/3] drivers/staging/cx25821: Use kstrdup

Julia Lawall julia at diku.dk
Mon Oct 18 17:44:52 UTC 2010


On Mon, 18 Oct 2010, Joe Perches wrote:

> Perhaps it's more readable code to recheck the
> field name flag and introduce a temporary
> char *fname so the slightly unusual reuse of
> 	field = kstrdup(field, GFP)
> becomes
> 	field = kstrdup(fname, GFP)

Before I had a local variable filename.  I preferred that because I felt 
uneasy about putting both statically and dynamically allocated memory in 
the same field.  But it does mean adding a new local variable.

I'm not sure to understand "recheck the field name flag", though.

julia


> ---
>  drivers/staging/cx25821/cx25821-audio-upstream.c   |   34 +++---------
>  .../staging/cx25821/cx25821-video-upstream-ch2.c   |   55 +++++++-------------
>  drivers/staging/cx25821/cx25821-video-upstream.c   |   53 +++++++------------
>  3 files changed, 47 insertions(+), 95 deletions(-)
> 
> diff --git a/drivers/staging/cx25821/cx25821-audio-upstream.c b/drivers/staging/cx25821/cx25821-audio-upstream.c
> index 27087db..180840f 100644
> --- a/drivers/staging/cx25821/cx25821-audio-upstream.c
> +++ b/drivers/staging/cx25821/cx25821-audio-upstream.c
> @@ -723,8 +723,6 @@ int cx25821_audio_upstream_init(struct cx25821_dev *dev, int channel_select)
>  {
>  	struct sram_channel *sram_ch;
>  	int retval = 0;
> -	int err = 0;
> -	int str_length = 0;
>  
>  	if (dev->_audio_is_running) {
>  		printk(KERN_WARNING "Audio Channel is still running so return!\n");
> @@ -752,28 +750,14 @@ int cx25821_audio_upstream_init(struct cx25821_dev *dev, int channel_select)
>  	dev->_audio_lines_count = LINES_PER_AUDIO_BUFFER;
>  	_line_size = AUDIO_LINE_SIZE;
>  
> -	if (dev->input_audiofilename) {
> -		str_length = strlen(dev->input_audiofilename);
> -		dev->_audiofilename = kmalloc(str_length + 1, GFP_KERNEL);
> -
> -		if (!dev->_audiofilename)
> -			goto error;
> -
> -		memcpy(dev->_audiofilename, dev->input_audiofilename,
> -		       str_length + 1);
> -
> -		/* Default if filename is empty string */
> -		if (strcmp(dev->input_audiofilename, "") == 0)
> -			dev->_audiofilename = "/root/audioGOOD.wav";
> -
> -	} else {
> -		str_length = strlen(_defaultAudioName);
> -		dev->_audiofilename = kmalloc(str_length + 1, GFP_KERNEL);
> -
> -		if (!dev->_audiofilename)
> -			goto error;
> -
> -		memcpy(dev->_audiofilename, _defaultAudioName, str_length + 1);
> +	if (!dev->input_audiofilename || *dev->input_audiofilename == 0)
> +		dev->_audiofilename = _defaultAudioName;
> +	else
> +		dev->_audiofilename = dev->input_audiofilename;
> +	dev->_audiofilename = kstrdup(dev->_audiofilename, GFP_KERNEL);
> +	if (!dev->_audiofilename) {
> +		retval = -ENOMEM;
> +		goto error;
>  	}
>  
>  	retval =
> @@ -802,5 +786,5 @@ int cx25821_audio_upstream_init(struct cx25821_dev *dev, int channel_select)
>  error:
>  	cx25821_dev_unregister(dev);
>  
> -	return err;
> +	return retval;
>  }
> diff --git a/drivers/staging/cx25821/cx25821-video-upstream-ch2.c b/drivers/staging/cx25821/cx25821-video-upstream-ch2.c
> index d12dbb5..fa7cd70 100644
> --- a/drivers/staging/cx25821/cx25821-video-upstream-ch2.c
> +++ b/drivers/staging/cx25821/cx25821-video-upstream-ch2.c
> @@ -747,10 +747,9 @@ int cx25821_vidupstream_init_ch2(struct cx25821_dev *dev, int channel_select,
>  	struct sram_channel *sram_ch;
>  	u32 tmp;
>  	int retval = 0;
> -	int err = 0;
>  	int data_frame_size = 0;
>  	int risc_buffer_size = 0;
> -	int str_length = 0;
> +	char *fname;
>  
>  	if (dev->_is_running_ch2) {
>  		printk("Video Channel is still running so return!\n");
> @@ -788,39 +787,23 @@ int cx25821_vidupstream_init_ch2(struct cx25821_dev *dev, int channel_select,
>  	risc_buffer_size =
>  	    dev->_isNTSC_ch2 ? NTSC_RISC_BUF_SIZE : PAL_RISC_BUF_SIZE;
>  
> -	if (dev->input_filename_ch2) {
> -		str_length = strlen(dev->input_filename_ch2);
> -		dev->_filename_ch2 = kmalloc(str_length + 1, GFP_KERNEL);
> -
> -		if (!dev->_filename_ch2)
> -			goto error;
> -
> -		memcpy(dev->_filename_ch2, dev->input_filename_ch2,
> -		       str_length + 1);
> -	} else {
> -		str_length = strlen(dev->_defaultname_ch2);
> -		dev->_filename_ch2 = kmalloc(str_length + 1, GFP_KERNEL);
> -
> -		if (!dev->_filename_ch2)
> -			goto error;
> -
> -		memcpy(dev->_filename_ch2, dev->_defaultname_ch2,
> -		       str_length + 1);
> -	}
> -
> -       /* Default if filename is empty string */
> -	if (strcmp(dev->input_filename_ch2, "") == 0) {
> -		if (dev->_isNTSC_ch2) {
> -			dev->_filename_ch2 =
> -			    (dev->_pixel_format_ch2 ==
> -			     PIXEL_FRMT_411) ? "/root/vid411.yuv" :
> -			    "/root/vidtest.yuv";
> -		} else {
> -			dev->_filename_ch2 =
> -			    (dev->_pixel_format_ch2 ==
> -			     PIXEL_FRMT_411) ? "/root/pal411.yuv" :
> -			    "/root/pal422.yuv";
> -		}
> +	if (dev->input_filename_ch2 && *dev->input_filename_ch2)
> +		fname = dev->input_filename_ch2;
> +	else if (dev->input_filename_ch2) {
> +		/* Default if filename is empty string */
> +		if (dev->_isNTSC_ch2)
> +			fname = (dev->_pixel_format_ch2 == PIXEL_FRMT_411) ?
> +				"/root/vid411.yuv" : "/root/vidtest.yuv";
> +		else
> +			fname = (dev->_pixel_format_ch2 == PIXEL_FRMT_411) ?
> +				"/root/pal411.yuv" : "/root/pal422.yuv";
> +	} else
> +		fname = dev->_defaultname_ch2;
> +
> +	dev->_filename_ch2 = kstrdup(fname, GFP_KERNEL);
> +	if (!dev->_filename_ch2) {
> +		retval = -ENOMEM;
> +		goto error;
>  	}
>  
>  	retval =
> @@ -851,5 +834,5 @@ int cx25821_vidupstream_init_ch2(struct cx25821_dev *dev, int channel_select,
>        error:
>  	cx25821_dev_unregister(dev);
>  
> -	return err;
> +	return retval;
>  }
> diff --git a/drivers/staging/cx25821/cx25821-video-upstream.c b/drivers/staging/cx25821/cx25821-video-upstream.c
> index 756a820..d51c6c1 100644
> --- a/drivers/staging/cx25821/cx25821-video-upstream.c
> +++ b/drivers/staging/cx25821/cx25821-video-upstream.c
> @@ -800,10 +800,9 @@ int cx25821_vidupstream_init_ch1(struct cx25821_dev *dev, int channel_select,
>  	struct sram_channel *sram_ch;
>  	u32 tmp;
>  	int retval = 0;
> -	int err = 0;
>  	int data_frame_size = 0;
>  	int risc_buffer_size = 0;
> -	int str_length = 0;
> +	char *fname;
>  
>  	if (dev->_is_running) {
>  		printk(KERN_INFO "Video Channel is still running so return!\n");
> @@ -840,37 +839,23 @@ int cx25821_vidupstream_init_ch1(struct cx25821_dev *dev, int channel_select,
>  	risc_buffer_size =
>  	    dev->_isNTSC ? NTSC_RISC_BUF_SIZE : PAL_RISC_BUF_SIZE;
>  
> -	if (dev->input_filename) {
> -		str_length = strlen(dev->input_filename);
> -		dev->_filename = kmalloc(str_length + 1, GFP_KERNEL);
> -
> -		if (!dev->_filename)
> -			goto error;
> -
> -		memcpy(dev->_filename, dev->input_filename, str_length + 1);
> -	} else {
> -		str_length = strlen(dev->_defaultname);
> -		dev->_filename = kmalloc(str_length + 1, GFP_KERNEL);
> -
> -		if (!dev->_filename)
> -			goto error;
> -
> -		memcpy(dev->_filename, dev->_defaultname, str_length + 1);
> -	}
> -
> -	/* Default if filename is empty string */
> -	if (strcmp(dev->input_filename, "") == 0) {
> -		if (dev->_isNTSC) {
> -			dev->_filename =
> -			    (dev->_pixel_format ==
> -			     PIXEL_FRMT_411) ? "/root/vid411.yuv" :
> -			    "/root/vidtest.yuv";
> -		} else {
> -			dev->_filename =
> -			    (dev->_pixel_format ==
> -			     PIXEL_FRMT_411) ? "/root/pal411.yuv" :
> -			    "/root/pal422.yuv";
> -		}
> +	if (dev->input_filename && *dev->input_filename)
> +		fname = dev->input_filename;
> +	else if (dev->input_filename) {
> +		/* Default if filename is empty string */
> +		if (dev->_isNTSC)
> +			fname = (dev->_pixel_format == PIXEL_FRMT_411) ?
> +				"/root/vid411.yuv" : "/root/vidtest.yuv";
> +		else
> +			fname = (dev->_pixel_format == PIXEL_FRMT_411) ?
> +				"/root/pal411.yuv" : "/root/pal422.yuv";
> +	} else
> +		fname = dev->_defaultname;
> +
> +	dev->_filename = kstrdup(fname, GFP_KERNEL);
> +	if (!dev->_filename) {
> +		retval = -ENOMEM;
> +		goto error;
>  	}
>  
>  	dev->_is_running = 0;
> @@ -908,5 +893,5 @@ int cx25821_vidupstream_init_ch1(struct cx25821_dev *dev, int channel_select,
>  error:
>  	cx25821_dev_unregister(dev);
>  
> -	return err;
> +	return retval;
>  }
> 
> 
> 



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