Messages in this thread | | | From | Kai-Heng Feng <> | Date | Tue, 4 Jul 2023 12:27:39 +0800 | Subject | Re: [PATCH] EDAC/Intel: Fix shift-out-of-bounds when DIMM/NVDIMM is absent |
| |
On Wed, Jun 14, 2023 at 3:58 PM Kai-Heng Feng <kai.heng.feng@canonical.com> wrote: > > On Wed, May 17, 2023 at 3:49 PM Kai-Heng Feng > <kai.heng.feng@canonical.com> wrote: > > > > On Wed, May 17, 2023 at 1:13 AM Luck, Tony <tony.luck@intel.com> wrote: > > > > > > >> [ 13.875282] Hardware name: HP HP Z4 G5 Workstation Desktop PC/8962, > > > > > BIOS U61 Ver. 01.01.15 04/19/2023 > > > > > > > > > >> When a DIMM slot is empty, the read value of mtr can be 0xffffffff, therefore > > > > > > > Looked like a buggy BIOS/hw that didn't set the mtr register. > > > > > > > > 1. Did you print the mtr register whose value was 0xffffffff? > > > > 2. Can you take a dmesg log with kernel "CONFIG_EDAC_DEBUG=y" enabled? > > > > 3. What was the CPU? Please take the output of "lscpu". > > > > 4. Did you verify your patch that the issue was fixed on your systems? > > > > > > I wonder if BIOS is "hiding" some devices from the OS? The 0xffffffff return is > > > the standard PCI response for reading a non-existent register. But that doesn't > > > quite make sense with having a "dimm present" bit in the MTR register. If > > > the register only exists if the DIMM is present, then there is no need for > > > a "dimm present" bit. > > > > I wonder if the "non-existent register" read is intended? > > > > > > > > Some "lspci" output may also be useful. > > > > lspci can be found in [1]: > > > > [1] https://bugzilla.kernel.org/show_bug.cgi?id=217453 > > A gentle ping...
Another gentle ping...
> > > > > Kai-Heng > > > > > > > > -Tony
| |