On Wed, Jan 22, 2014 at 03:19:48PM +0800, Chris Ruehl wrote: > On Wednesday, January 22, 2014 02:42 PM, Sascha Hauer wrote: > >On Wed, Jan 22, 2014 at 12:32:39PM +0800, Chris Ruehl wrote: > >>Function mxcmci_request() throw an exception on a imx27 cpu. > >>This patch fix the problem by test the pointer before access it. > >> > >>diff --git a/drivers/mmc/host/mxcmmc.c b/drivers/mmc/host/mxcmmc.c > >>index f7199c8..8645d6a 100644 > >>--- a/drivers/mmc/host/mxcmmc.c > >>+++ b/drivers/mmc/host/mxcmmc.c > >>@@ -347,7 +347,7 @@ static int mxcmci_setup_data(struct mxcmci_host *host, struct mmc_data *data) > >> return 0; > >> for_each_sg(data->sg, sg, data->sg_len, i) { > >>- if (sg->offset & 3 || sg->length & 3 || sg->length < 512) { > >>+ if (sg && (sg->offset & 3 || sg->length & 3 || sg->length < 512)) { > >The question is why sg is NULL. I think this shouldn't happen. > > > >Sascha > > > Thats was my idea too. But had no time to debug it out. > As for_each_sg() iterate over the sg-list may its not set properly > before - In an earlier post > I ask for help but no-one returned so I quick fixed it. Maybe now > the bell is loud enough ;-) Please try to track it further down. Does this happen every time you are in this function or does it happen only every once in a while? Does it happen in the first iteration of the loop? is it an SDIO card or regular SD card? Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html