On 1/15/2018 9:48 AM, Rob Clark wrote:
> On Fri, Jan 12, 2018 at 3:55 PM, Lloyd Atkinson <latkinso@xxxxxxxxxxxxxx> wrote:
>> Move null checks of pointer arguments to the beginning of the
>> modeset init function since they are referenced immediately
>> instead of after they have already been used.
>>
>> Signed-off-by: Lloyd Atkinson <latkinso@xxxxxxxxxxxxxx>
>> ---
>> drivers/gpu/drm/msm/dsi/dsi.c | 22 ++++++++++------------
>> 1 file changed, 10 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/msm/dsi/dsi.c b/drivers/gpu/drm/msm/dsi/dsi.c
>> index 98742d7..be855db 100644
>> --- a/drivers/gpu/drm/msm/dsi/dsi.c
>> +++ b/drivers/gpu/drm/msm/dsi/dsi.c
>> @@ -196,7 +196,7 @@ int msm_dsi_modeset_init(struct msm_dsi *msm_dsi, struct drm_device *dev,
>> struct drm_bridge *ext_bridge;
>> int ret;
>>
>> - if (WARN_ON(!encoder))
>> + if (!encoder || !msm_dsi || !dev)
>
> hmm, the checking if msm_dsi is null later in the fail: case is
> certainly sketchy after we've already deref'd it.. so this looks like
> the right thing. But I'd like to keep the WARN_ON(), since this is a
> case that shouldn't really happen. The WARN_ON() nicely documents
> that none of these parameters are expected to be NULL, and it gives a
> big shouty message to anyone who inadvertently changes something that
> breaks that assumption. Other than that, it looks good.
>
> BR,
> -R
Sure. Do you want to add WARN_ONs to msm_dsi and dev as well?
Thanks,
Lloyd
>
>
>> return -EINVAL;
>>
>> msm_dsi->dev = dev;
>> @@ -245,19 +245,17 @@ int msm_dsi_modeset_init(struct msm_dsi *msm_dsi, struct drm_device *dev,
>>
>> return 0;
>> fail:
>> - if (msm_dsi) {
>> - /* bridge/connector are normally destroyed by drm: */
>> - if (msm_dsi->bridge) {
>> - msm_dsi_manager_bridge_destroy(msm_dsi->bridge);
>> - msm_dsi->bridge = NULL;
>> - }
>> + /* bridge/connector are normally destroyed by drm: */
>> + if (msm_dsi->bridge) {
>> + msm_dsi_manager_bridge_destroy(msm_dsi->bridge);
>> + msm_dsi->bridge = NULL;
>> + }
>>
>> - /* don't destroy connector if we didn't make it */
>> - if (msm_dsi->connector && !msm_dsi->external_bridge)
>> - msm_dsi->connector->funcs->destroy(msm_dsi->connector);
>> + /* don't destroy connector if we didn't make it */
>> + if (msm_dsi->connector && !msm_dsi->external_bridge)
>> + msm_dsi->connector->funcs->destroy(msm_dsi->connector);
>>
>> - msm_dsi->connector = NULL;
>> - }
>> + msm_dsi->connector = NULL;
>>
>> return ret;
>> }
>> --
>> QUALCOMM Canada, on behalf of Qualcomm Innovation Center, Inc. is a member
>> of Code Aurora Forum, hosted by The Linux Foundation
>>
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