From 164c29244d4beb9a105102c42821f4925e4a0c7a Mon Sep 17 00:00:00 2001 From: Tony Luck Date: Wed, 28 Jun 2017 16:44:07 -0700 Subject: [PATCH] EDAC, pnd2: Fix Apollo Lake DIMM detection Non-existent or empty DIMM slots result in error return from RD_REGP(). But we shouldn't give up on failure. So long as we find at least one DIMM we can continue. Signed-off-by: Tony Luck Cc: Qiuxu Zhuo Cc: linux-edac Link: http://lkml.kernel.org/r/20170628234407.21521-1-tony.luck@intel.com Signed-off-by: Borislav Petkov --- drivers/edac/pnd2_edac.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/edac/pnd2_edac.c b/drivers/edac/pnd2_edac.c index 407f239..8e59949 100644 --- a/drivers/edac/pnd2_edac.c +++ b/drivers/edac/pnd2_edac.c @@ -424,16 +424,21 @@ static void dnv_mk_region(char *name, struct region *rp, void *asym) static int apl_get_registers(void) { + int ret = -ENODEV; int i; if (RD_REG(&asym_2way, b_cr_asym_2way_mem_region_mchbar)) return -ENODEV; + /* + * RD_REGP() will fail for unpopulated or non-existent + * DIMM slots. Return success if we find at least one DIMM. + */ for (i = 0; i < APL_NUM_CHANNELS; i++) - if (RD_REGP(&drp0[i], d_cr_drp0, apl_dports[i])) - return -ENODEV; + if (!RD_REGP(&drp0[i], d_cr_drp0, apl_dports[i])) + ret = 0; - return 0; + return ret; } static int dnv_get_registers(void) -- 2.7.4