3.16.74-rc1 review patch. If anyone has any objections, please let me know.
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From: Arnd Bergmann arnd@arndb.de
commit 0e633f97162c1c74c68e2eb20bbd9259dce87cd9 upstream.
clang warns about a possible variable use that gcc never complained about:
drivers/media/platform/davinci/isif.c:982:32: error: variable 'frame_size' is uninitialized when used here [-Werror,-Wuninitialized] dm365_vpss_set_pg_frame_size(frame_size); ^~~~~~~~~~ drivers/media/platform/davinci/isif.c:887:2: note: variable 'frame_size' is declared here struct vpss_pg_frame_size frame_size; ^ 1 error generated.
There is no initialization for this variable at all, and there has never been one in the mainline kernel, so we really should not put that stack data into an mmio register.
On the other hand, I suspect that gcc checks the condition more closely and notices that the global isif_cfg.bayer.config_params.test_pat_gen flag is initialized to zero and never written to from any code path, so anything depending on it can be eliminated.
To shut up the clang warning, just remove the dead code manually, it has probably never been used because any attempt to do so would have resulted in undefined behavior.
Fixes: 63e3ab142fa3 ("V4L/DVB: V4L - vpfe capture - source for ISIF driver on DM365")
Signed-off-by: Arnd Bergmann arnd@arndb.de Reviewed-by: Nathan Chancellor natechancellor@gmail.com Acked-by: Lad, Prabhakar prabhakar.csengg@gmail.com Signed-off-by: Hans Verkuil hverkuil-cisco@xs4all.nl Signed-off-by: Mauro Carvalho Chehab mchehab+samsung@kernel.org Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/media/platform/davinci/isif.c | 9 --------- 1 file changed, 9 deletions(-)
--- a/drivers/media/platform/davinci/isif.c +++ b/drivers/media/platform/davinci/isif.c @@ -890,9 +890,7 @@ static int isif_set_hw_if_params(struct static int isif_config_ycbcr(void) { struct isif_ycbcr_config *params = &isif_cfg.ycbcr; - struct vpss_pg_frame_size frame_size; u32 modeset = 0, ccdcfg = 0; - struct vpss_sync_pol sync;
dev_dbg(isif_cfg.dev, "\nStarting isif_config_ycbcr...");
@@ -980,13 +978,6 @@ static int isif_config_ycbcr(void) /* two fields are interleaved in memory */ regw(0x00000249, SDOFST);
- /* Setup test pattern if enabled */ - if (isif_cfg.bayer.config_params.test_pat_gen) { - sync.ccdpg_hdpol = params->hd_pol; - sync.ccdpg_vdpol = params->vd_pol; - dm365_vpss_set_sync_pol(sync); - dm365_vpss_set_pg_frame_size(frame_size); - } return 0; }