The patch below does not apply to the 3.5-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From deb09ddaff1435f72dd598d38f9b58354c68a5ec Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab <[email protected]> Date: Thu, 20 Sep 2012 12:09:30 -0300 Subject: [PATCH] sb_edac: Avoid overflow errors at memory size calculation Sandy bridge EDAC is calculating the memory size with overflow. Basically, the size field and the integer calculation is using 32 bits. More bits are needed, when the DIMM memories have high density. The net result is that memories are improperly reported there, when high-density DIMMs are used: EDAC DEBUG: in drivers/edac/sb_edac.c, line at 591: mc#0: channel 0, dimm 0, -16384 Mb (-4194304 pages) bank: 8, rank: 2, row: 0x10000, col: 0x800 EDAC DEBUG: in drivers/edac/sb_edac.c, line at 591: mc#0: channel 1, dimm 0, -16384 Mb (-4194304 pages) bank: 8, rank: 2, row: 0x10000, col: 0x800 As the number of pages value is handled at the EDAC core as unsigned ints, the driver shows the 16 GB memories at sysfs interface as 16760832 MB! The fix is simple: calculate the number of pages as unsigned 64-bits integer. After the patch, the memory size (16 GB) is properly detected: EDAC DEBUG: in drivers/edac/sb_edac.c, line at 592: mc#0: channel 0, dimm 0, 16384 Mb (4194304 pages) bank: 8, rank: 2, row: 0x10000, col: 0x800 EDAC DEBUG: in drivers/edac/sb_edac.c, line at 592: mc#0: channel 1, dimm 0, 16384 Mb (4194304 pages) bank: 8, rank: 2, row: 0x10000, col: 0x800 Cc: [email protected] Signed-off-by: Mauro Carvalho Chehab <[email protected]> diff --git a/drivers/edac/sb_edac.c b/drivers/edac/sb_edac.c index f3b1f9f..5715b7c 100644 --- a/drivers/edac/sb_edac.c +++ b/drivers/edac/sb_edac.c @@ -513,7 +513,8 @@ static int get_dimm_config(struct mem_ctl_info *mci) { struct sbridge_pvt *pvt = mci->pvt_info; struct dimm_info *dimm; - int i, j, banks, ranks, rows, cols, size, npages; + unsigned i, j, banks, ranks, rows, cols, npages; + u64 size; u32 reg; enum edac_type mode; enum mem_type mtype; @@ -585,10 +586,10 @@ static int get_dimm_config(struct mem_ctl_info *mci) cols = numcol(mtr); /* DDR3 has 8 I/O banks */ - size = (rows * cols * banks * ranks) >> (20 - 3); + size = ((u64)rows * cols * banks * ranks) >> (20 - 3); npages = MiB_TO_PAGES(size); - edac_dbg(0, "mc#%d: channel %d, dimm %d, %d Mb (%d pages) bank: %d, rank: %d, row: %#x, col: %#x\n", + edac_dbg(0, "mc#%d: channel %d, dimm %d, %Ld Mb (%d pages) bank: %d, rank: %d, row: %#x, col: %#x\n", pvt->sbridge_dev->mc, i, j, size, npages, banks, ranks, rows, cols); -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
