From mboxrd@z Thu Jan 1 00:00:00 1970 From: walter harms Date: Thu, 16 Feb 2017 12:03:56 +0000 Subject: Re: [patch] drm/msm/dsi: free first element on error Message-Id: <58A5952C.105@bfs.de> List-Id: References: <20170216105042.GA25544@mwanda> <87a89mnznw.fsf@intel.com> <20170216115307.GD4108@mwanda> In-Reply-To: <20170216115307.GD4108@mwanda> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Dan Carpenter Cc: Jani Nikula , Rob Clark , Archit Taneja , linux-arm-msm@vger.kernel.org, kernel-janitors@vger.kernel.org, dri-devel@lists.freedesktop.org, Wei Yongjun , freedreno@lists.freedesktop.org Am 16.02.2017 12:53, schrieb Dan Carpenter: > On Thu, Feb 16, 2017 at 01:27:47PM +0200, Jani Nikula wrote: >> On Thu, 16 Feb 2017, Dan Carpenter wrote: >>> We want to free msm_host->bus_clks[0] so the > should be >=. >>> >>> Fixes: 6e0eb52eba9e ("drm/msm/dsi: Parse bus clocks from a list") >>> Signed-off-by: Dan Carpenter >>> >>> diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c >>> index 1fc07ce24686..239e79b39a45 100644 >>> --- a/drivers/gpu/drm/msm/dsi/dsi_host.c >>> +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c >>> @@ -437,7 +437,7 @@ static int dsi_bus_clk_enable(struct msm_dsi_host *msm_host) >>> >>> return 0; >>> err: >>> - for (; i > 0; i--) >>> + for (; i >= 0; i--) >>> clk_disable_unprepare(msm_host->bus_clks[i]); >> >> By the looks of it this is also wrong. I didn't look at the functions, >> but you probably don't want to unprepare something where prepare failed, >> i.e. you want to -1 both the start and end offsets. Perhaps the right >> fix is >> >> while (i--) >> clk_disable_unprepare(msm_host->bus_clks[i]); >> >> which also seems to be widely used on error paths. >> > We already know that programmers are bad in counting backwards ... any chance to make that into a forward loop ? re, wh