[PATCH] EDAC/amd64: Read back the scrub rate PCI register on F15h

[Borislav Petkov <bp@alien8.de>]

On Thu, Jun 18, 2020 at 07:56:46PM +0200, Borislav Petkov wrote:
> Oh, you're manipulating it alright but there's a bug in reporting it.
> Wanna test a patch?

Here it is:

---
From: Borislav Petkov <bp@suse.de>

Commit:

  da92110dfdfa ("EDAC, amd64_edac: Extend scrub rate support to F15hM60h")

added support for F15h, model 0x60 CPUs but in doing so, missed to read
back SCRCTRL PCI config register on F15h CPUs which are *not* model
0x60. Add that read so that doing

  $ cat /sys/devices/system/edac/mc/mc0/sdram_scrub_rate

can show the previously set DRAM scrub rate.

Fixes: da92110dfdfa ("EDAC, amd64_edac: Extend scrub rate support to F15hM60h")
Reported-by: Anders Andersson <pipatron@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org> #v4.4..
Link: https://lkml.kernel.org/r/CAKkunMbNWppx_i6xSdDHLseA2QQmGJqj_crY=NF-GZML5np4Vw@mail.gmail.com
---
 drivers/edac/amd64_edac.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
index ef90070a9194..6262f6370c5d 100644
--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -269,6 +269,8 @@ static int get_scrub_rate(struct mem_ctl_info *mci)
 
 		if (pvt->model == 0x60)
 			amd64_read_pci_cfg(pvt->F2, F15H_M60H_SCRCTRL, &scrubval);
+		else
+			amd64_read_pci_cfg(pvt->F3, SCRCTRL, &scrubval);
 	} else {
 		amd64_read_pci_cfg(pvt->F3, SCRCTRL, &scrubval);
 	}
-- 
2.21.0

-- 
Regards/Gruss,
    Boris.

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