Hi Shimoda-san, On Tue, Oct 17, 2017 at 9:30 AM, Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> wrote: > Since this driver checks if the return value of dma_map_sg() is minus > or not and keeps to enable the DMAC, it may cause kernel panic when > the dma_map_sg() returns 0. So, this patch fixes the issue. Thanks for your patch! Indeed: * dma_maps_sg_attrs returns 0 on error and > 0 on success. * It should never return a value < 0. A quick grep shows there are 4 more offenders: - drivers/crypto/qce/ablkcipher.c - drivers/crypto/qce/sha.c - drivers/hsi/controllers/omap_ssi_port.c - drivers/mailbox/bcm-flexrm-mailbox.c > Reported-by: Dirk Behme <dirk.behme@xxxxxxxxxxxx> > Fixes: 2a68ea7896e3 ("mmc: renesas-sdhi: add support for R-Car Gen3 SDHI DMAC") > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds