On Thu, Jun 2, 2016 at 2:58 AM, Bjorn Andersson <bjorn.andersson@xxxxxxxxxx> wrote: > On Sun, May 29, 2016 at 12:04 AM, Chen-Yu Tsai <wens@xxxxxxxx> wrote: >> When IS_ERR_VALUE was removed from the mmc core code, it was replaced >> with a simple not-zero check. This does not work, as the value checked >> is the return value for mmc_select_bus_width, which returns the set >> bit width on success. This made eMMC modes higher than HS-DDR unusable. >> >> Fix this by checking for a positive return value instead. > > mmc_select_bus_width() can return 0 on "success" as well and the > previous check was !IS_ERR_VALUE(err), which coverts that. So I > believe these checks should be for err >= 0 rather than just > 0. >From the comments above the function: "Zero is returned instead of error value if the wide width is not supported." The documents I found, which were more vendor datasheets, only list bit widths 4 and 8 for high speed SDR/DDR and HS200. Not sure what the MMC spec actually says though, as I do not have it. Regards ChenYu > > > Either way this fixes the boot failures seen on my Qualcomm based > boards with v4.7-rc1. > > Regards, > Bjorn -- 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
