From 416dad018edd66eb330e07b9885c342f5822f4ce Mon Sep 17 00:00:00 2001 From: Jean-Philippe Brucker Date: Fri, 17 Apr 2020 16:23:26 +0200 Subject: mtd: cfi_cmdset_0001: Support the absence of protection registers MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ Upstream commit b359ed5184aebf9d987e54abc5dae7ac03ed29ae ] The flash controller implemented by the Arm Base platform behaves like the Intel StrataFlash J3 device, but omits several features. In particular it doesn't implement a protection register, so "Number of Protection register fields" in the Primary Vendor-Specific Extended Query, is 0. The Intel StrataFlash J3 datasheet only lists 1 as a valid value for NumProtectionFields. It describes the field as: "Number of Protection register fields in JEDEC ID space. “00h,” indicates that 256 protection bytes are available" While a value of 0 may arguably not be architecturally valid, the driver's current behavior is certainly wrong: if NumProtectionFields is 0, read_pri_intelext() adds a negative value to the unsigned extra_size, and ends up in an infinite loop. Fix it by ignoring a NumProtectionFields of 0. Signed-off-by: Jean-Philippe Brucker Tested-by: Sudeep Holla Tested-by: Catalin Marinas Signed-off-by: Vignesh Raghavendra Stable-dep-of: 565fe150624e ("mtd: cfi_cmdset_0001: Byte swap OTP info") Signed-off-by: Sasha Levin --- drivers/mtd/chips/cfi_cmdset_0001.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c index 79a53cb8507b..1d77687b6716 100644 --- a/drivers/mtd/chips/cfi_cmdset_0001.c +++ b/drivers/mtd/chips/cfi_cmdset_0001.c @@ -420,8 +420,9 @@ read_pri_intelext(struct map_info *map, __u16 adr) extra_size = 0; /* Protection Register info */ - extra_size += (extp->NumProtectionFields - 1) * - sizeof(struct cfi_intelext_otpinfo); + if (extp->NumProtectionFields) + extra_size += (extp->NumProtectionFields - 1) * + sizeof(struct cfi_intelext_otpinfo); } if (extp->MinorVersion >= '1') { @@ -695,14 +696,16 @@ static int cfi_intelext_partition_fixup(struct mtd_info *mtd, */ if (extp && extp->MajorVersion == '1' && extp->MinorVersion >= '3' && extp->FeatureSupport & (1 << 9)) { + int offs = 0; struct cfi_private *newcfi; struct flchip *chip; struct flchip_shared *shared; - int offs, numregions, numparts, partshift, numvirtchips, i, j; + int numregions, numparts, partshift, numvirtchips, i, j; /* Protection Register info */ - offs = (extp->NumProtectionFields - 1) * - sizeof(struct cfi_intelext_otpinfo); + if (extp->NumProtectionFields) + offs = (extp->NumProtectionFields - 1) * + sizeof(struct cfi_intelext_otpinfo); /* Burst Read info */ offs += extp->extra[offs+1]+2; -- cgit v1.2.3