Re: [PATCH v4 9/9] Documentation: ABI: Add sysfs ABI documentation for DDR training data
Manivannan Sadhasivam <[email protected]> Mon, 13 Apr 2026 17:29:46 +0530
| Newsgroups | dev.linux.lists.mhi,org.freedesktop.lists.dri-devel,org.kernel.vger.linux-arm-msm,org.kernel.vger.linux-doc,org.kernel.vger.linux-kernel |
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| Message-ID | <yttrssaw4k2vx7r6l4vsb535qcrr4phsgj6qlnu2r764inai7o@d4qgr7uu5t2s> |
On Thu, Mar 19, 2026 at 12:01:49PM +0530, Kishore Batta wrote: > Add ABI documentation for the DDR training data sysfs attribute exposed by > the sahara MHI driver. > > The documented sysfs node provides read-only access to the DDR training > data captured during sahara command mode and exposed via the MHI > controller device. This allows userspace to read the training data and > manage it as needed outside the kernel. > > Signed-off-by: Kishore Batta <[email protected]> Ah, this should be squashed with previous patch. - Mani > --- > .../ABI/testing/sysfs-bus-mhi-ddr_training_data | 19 +++++++++++++++++++ > 1 file changed, 19 insertions(+) > > diff --git a/Documentation/ABI/testing/sysfs-bus-mhi-ddr_training_data b/Documentation/ABI/testing/sysfs-bus-mhi-ddr_training_data > new file mode 100644 > index 0000000000000000000000000000000000000000..810b487b5a5fdba133d81255f9879844e3938a10 > --- /dev/null > +++ b/Documentation/ABI/testing/sysfs-bus-mhi-ddr_training_data > @@ -0,0 +1,19 @@ > +What: /sys/bus/mhi/devices/<mhi-cntrl>/ddr_training_data > + > +Date: March 2026 > + > +Contact: Kishore Batta <[email protected]> > + > +Description: Contains the DDR training data for the Qualcomm device > + connected. MHI driver populates different controller > + nodes for each device. The DDR training data is exposed > + to userspace to read and save the training data file to > + the filesystem. In the subsequent boot up of the device, > + the training data is restored from host to device > + optimizing the boot up time of the device. > + > +Usage: Example for reading DDR training data: > + cat /sys/bus/mhi/devices/mhi0/ddr_training_data > + > +Permissions: The file permissions are set to 0444 allowing read > + access. > > -- > 2.34.1 > -- மணிவண்ணன் சதாசிவம்