From: Arnd Bergmann Date: Sun, 3 Jan 2021 13:57:29 +0000 (+0100) Subject: dmaengine: qcom: fix gpi undefined behavior X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=0bd1bf86ab79555425b9f0b63005e181defe4da6;p=linux.git dmaengine: qcom: fix gpi undefined behavior gcc points out an incorrect error handling loop: drivers/dma/qcom/gpi.c: In function 'gpi_ch_init': drivers/dma/qcom/gpi.c:1254:15: error: iteration 2 invokes undefined behavior [-Werror=aggressive-loop-optimizations] 1254 | struct gpii *gpii = gchan->gpii; | ^~~~ drivers/dma/qcom/gpi.c:1951:2: note: within this loop 1951 | for (i = i - 1; i >= 0; i++) { | ^~~ Change the loop to correctly walk backwards through the initialized fields rather than off into the woods. Fixes: 5d0c3533a19f ("dmaengine: qcom: Add GPI dma driver") Signed-off-by: Arnd Bergmann Link: https://lore.kernel.org/r/20210103135738.3741123-1-arnd@kernel.org Signed-off-by: Vinod Koul --- diff --git a/drivers/dma/qcom/gpi.c b/drivers/dma/qcom/gpi.c index 556c070a514ca..1a0bf6b0567a5 100644 --- a/drivers/dma/qcom/gpi.c +++ b/drivers/dma/qcom/gpi.c @@ -1948,7 +1948,7 @@ static int gpi_ch_init(struct gchan *gchan) return ret; error_start_chan: - for (i = i - 1; i >= 0; i++) { + for (i = i - 1; i >= 0; i--) { gpi_stop_chan(&gpii->gchan[i]); gpi_send_cmd(gpii, gchan, GPI_CH_CMD_RESET); }