In mci_extract_erase_group_size() we test for (IS_SD() && csd_struct_v1) which means that for non csd_struct_v1 SD cards we fall into the MMC path and evaluate ext_csd. This doesn't exist for SD cards and the code crashes with a NULL pointer deref. Fix this by always falling into the SD case for SD cards. Add the missing erase_grp_size extraction for csd_struct v0 cards. The code for that is taken from the corresponding Linux code. Fixes: 91a11c7d50 ("mci: add support for discarding write blocks") Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> --- drivers/mci/mci-core.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/drivers/mci/mci-core.c b/drivers/mci/mci-core.c index ec4a5c0749..48a3df9ec9 100644 --- a/drivers/mci/mci-core.c +++ b/drivers/mci/mci-core.c @@ -1228,9 +1228,20 @@ static void mci_extract_erase_group_size(struct mci *mci) return; - if (IS_SD(mci) && UNSTUFF_BITS(mci->csd, 126, 2) != 0) { - /* For SD with csd_struct v1, erase group is always one sector */ - mci->erase_grp_size = 1; + if (IS_SD(mci)) { + if (UNSTUFF_BITS(mci->csd, 126, 2) == 0) { + unsigned int write_blkbits = UNSTUFF_BITS(mci->csd, 22, 4); + + if (UNSTUFF_BITS(mci->csd, 46, 1)) { + mci->erase_grp_size = 1; + } else if (write_blkbits >= 9) { + mci->erase_grp_size = UNSTUFF_BITS(mci->csd, 39, 7) + 1; + mci->erase_grp_size <<= write_blkbits - 9; + } + } else { + /* For SD with csd_struct v1, erase group is always one sector */ + mci->erase_grp_size = 1; + } } else { if (mci->ext_csd[EXT_CSD_ERASE_GROUP_DEF] & 0x01) { /* Read out group size from ext_csd */ -- 2.39.5