Re: [PATCH v2] omapfb: dss: Handle return error in dss_init_ports.

From: Bartlomiej Zolnierkiewicz
Date: Thu Feb 09 2017 - 06:36:45 EST



Hi,

On Thursday, February 09, 2017 03:28:01 PM Arvind Yadav wrote:
> Here, dss_init_ports is not handling return error form
> dpi_init_port and sdi_init_port. Now dss_init_ports is returning
> always 0. And it's making below code as a dead code.
>
> static int dss_bind(struct device *dev)
> {
> .
> .
> r = dss_init_ports(pdev); //dss_init_ports will return always 0
> if (r)// This condition will always false
> goto err_init_ports; //Dead Code
> .
> .
> }
>
> This change is to handle return error from dpi_init_port and
> sdi_init_port. Also, It will remove dead code from function 'dss_bind'.
>
> Signed-off-by: Arvind Yadav <arvind.yadav.cs@xxxxxxxxx>
> ---

Please include version history here when submitting new
versions.

> drivers/video/fbdev/omap2/omapfb/dss/dss.c | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/video/fbdev/omap2/omapfb/dss/dss.c b/drivers/video/fbdev/omap2/omapfb/dss/dss.c
> index 47d7f69..87eb10c 100644
> --- a/drivers/video/fbdev/omap2/omapfb/dss/dss.c
> +++ b/drivers/video/fbdev/omap2/omapfb/dss/dss.c
> @@ -946,6 +946,7 @@ static int dss_init_ports(struct platform_device *pdev)
> struct device_node *parent = pdev->dev.of_node;
> struct device_node *port;
> int r;
> + int ret = 0;
>
> if (parent == NULL)
> return 0;
> @@ -972,17 +973,20 @@ static int dss_init_ports(struct platform_device *pdev)
>
> switch (port_type) {
> case OMAP_DISPLAY_TYPE_DPI:
> - dpi_init_port(pdev, port);
> + ret = dpi_init_port(pdev, port);
> break;
> case OMAP_DISPLAY_TYPE_SDI:
> - sdi_init_port(pdev, port);
> + ret = sdi_init_port(pdev, port);
> break;
> default:
> break;
> }
> } while ((port = omapdss_of_get_next_port(parent, port)) != NULL);

What about the other issue raised by me?

Shouldn't initialization be stopped after first failure?

i.e.:

} while (!ret && (port = omapdss_of_get_next_port(parent, port)) != NULL);

Otherwise it is possible to return a success in case when
- initialization of the first port fails
- initialization of the second port is successful

> - return 0;
> + if (ret)
> + dss_uninit_ports(pdev);
> +
> + return ret;
> }
>
> static void dss_uninit_ports(struct platform_device *pdev)

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics