Re: [PATCH 0/3] Add support to handle prefetchable memoryg

From: Vidya Sagar
Date: Tue Nov 17 2020 - 12:35:51 EST




On 11/17/2020 5:40 PM, Lorenzo Pieralisi wrote:
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On Tue, Nov 17, 2020 at 10:08:35AM +0530, Vidya Sagar wrote:
Hi Lorenzo & Bjorn,
Sorry to bother you.
Could you please take a look at the patches-1 & 2 from this series?

IIUC we should:

(1) apply https://patchwork.kernel.org/project/linux-pci/patch/20201026181652.418729-1-robh@xxxxxxxxxx
(2) apply [1,2] from this series

For (2), are they rebased against v5.10-rc3 with (1) applied ? I need to
check but I will probably have to use v5.10-rc3 as baseline owing to
commit:

9fff3256f93d

(1) depends on it.

Lorenzo
My patches [1,2] from this series apply cleanly on v5.10-rc3. But with (1) applied first, there is a trivial rebase required. Let me know if you want me to send the trivial rebased version (of patch-2 particularly).

Thanks,
Vidya Sagar

Thanks,
Vidya Sagar

On 11/4/2020 1:16 PM, Vidya Sagar wrote:
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Lorenzo / Bjorn,
Could you please review patches-1 & 2 in this series?
For the third patch, we already went with Rob's patch @
http://patchwork.ozlabs.org/project/linux-pci/patch/20201026154852.221483-1-robh@xxxxxxxxxx/


Thanks,
Vidya Sagar

On 10/26/2020 6:02 PM, Thierry Reding wrote:
On Sat, Oct 24, 2020 at 04:03:41AM +0000, Jingoo Han wrote:
On 10/23/20, 3:57 PM, Vidya Sagar wrote:

This patch series adds support for configuring the DesignWare IP's ATU
region for prefetchable memory translations.
It first starts by flagging a warning if the size of non-prefetchable
aperture goes beyond 32-bit as PCIe spec doesn't allow it.
And then adds required support for programming the ATU to handle higher
(i.e. >4GB) sizes and then finally adds support for differentiating
between prefetchable and non-prefetchable regions and
configuring one of
the ATU regions for prefetchable memory translations purpose.

Vidya Sagar (3):
PCI: of: Warn if non-prefetchable memory aperture size is > 32-bit
PCI: dwc: Add support to program ATU for >4GB memory aperture sizes
PCI: dwc: Add support to handle prefetchable memory mapping

For 2nd & 3rd,
Acked-by: Jingoo <jingoohan1@xxxxxxxxx>
But, I still want someone to ack 1st patch, not me.

To Vidya,
If possible, can you ask your coworker to give 'Tested-by'? It
will be very helpful.
Thank you.

On next-20201026 (but also going back quite a while) I'm seeing this
during boot on Jetson AGX Xavier (Tegra194):

[    3.493382] ahci 0001:01:00.0: version 3.0
[    3.493889] ahci 0001:01:00.0: SSS flag set, parallel bus scan
disabled
[    4.497706] ahci 0001:01:00.0: controller reset failed (0xffffffff)
[    4.498114] ahci: probe of 0001:01:00.0 failed with error -5

After applying this series, AHCI over PCI is back to normal:

[    3.543230] ahci 0001:01:00.0: AHCI 0001.0000 32 slots 1 ports 6
Gbps 0x1 impl SATA mode
[    3.550841] ahci 0001:01:00.0: flags: 64bit ncq sntf led only pmp
fbs pio slum part sxs
[    3.559747] scsi host0: ahci
[    3.561998] ata1: SATA max UDMA/133 abar m512@0x1230010000 port
0x1230010100 irq 63

So for the series:

Tested-by: Thierry Reding <treding@xxxxxxxxxx>