[lkml]   [2019]   [Jan]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH V7 1/2] arm64: dtsi: Fix SDMMC address range
On Wed, Jan 02, 2019 at 11:36:47AM -0800, Sowjanya Komatineni wrote:
> This patch fixes the SDMMC Controllers address space to be exact
> defined register address range as per the design.
> SDMMC Controller supporting Command Queue has CQHCI registers at
> offset 0xF000.
> This fix helps to identify the Tegra SDMMC Controllers supporting
> Command Queue based on the size of address space.
> Signed-off-by: Sowjanya Komatineni <>
> ---
> arch/arm64/boot/dts/nvidia/tegra186.dtsi | 6 +++---
> arch/arm64/boot/dts/nvidia/tegra194.dtsi | 4 ++--
> 2 files changed, 5 insertions(+), 5 deletions(-)

After applying these patches I'm having second thoughts about the DT
aspect of this. I know you and Timo had originally argued to advertise
the capability via an extra property in DT instead of updating the reg
property. In retrospect, I think that's the right thing to do, after

The problem I'm running into is that if I apply patch 2/2 without the
first patch, then both Jetson TX2 and Jetson AGX Xavier crash on boot
because they try to access these registers (the I/O memory size is
0x10000 for all controllers). So we're effectively breaking ABI with
existing device trees.

I don't know of a way to work around that other than the separate
property. Would you mind changing the series to contain:

1) a patch updating the device tree bindings with the new
optional property that would mark SDMMC4 as CQE capable
(make sure to Cc on that patch)

2) replace this patch by one which only adds the new
"supports-cqe" property

3) update the second patch to make the decision based on the
flag rather than the I/O memory size

Sorry for the back and forth on this. I evidently hadn't thought this

[unhandled content-type:application/pgp-signature]
 \ /
  Last update: 2019-01-10 15:48    [W:1.188 / U:0.920 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site