Hi,
On 26/07/2024 21:17, Théo Lebrun wrote:
> Currently, system-wide suspend is broken on J7200 because of a
> controller reset. The TI wrapper does not get re-initialised at resume
> and the first register access from cdns core fails.
>
> We address that in a few ways:
> - In cdns3-ti, if a reset has occured at resume, we reconfigure the HW.
> - We pass the XHCI_RESET_ON_RESUME quirk, meaning the XHCI core expects
> a resume.
OK.
> - We add a xhci->lost_power flag.
Why?
>
> The previous revision had one big issue: we had to know if
> reset-on-resume was true, at probe-time. This is where the main
Don't we already know this at probe-time? why not just rely on the existing
XHCI_RESET_ON_RESUME qurik, than add a new mechanism?
> difference with previous revisions is. We now pass the information from
> wrapper devices back up into XHCI. The xhci->lost_power flag gets its
> default value from the XHCI_RESET_ON_RESUME quirk. It however allows
> wrappers to signal *at resume* if they still expect a reset.
>
> That means wrappers that are unsure if they will reset should:
> - (1) set the quirk at probe and,
> - (2) potentially set xhci->lost_power to false at resume.
>
> We implement that for cdns3, by piggybacking on the host role ->resume()
> callback already receives the information from its caller.
>
> Have a nice day,
> Théo
>
> Signed-off-by: Théo Lebrun <theo.lebrun@xxxxxxxxxxx>
> ---
> Changes in v5:
> - dt-bindings: take Reviewed-by Rob and Conor for the first
> patch: "dt-bindings: usb: ti,j721e-usb: fix compatible list".
> - cdns3-ti:
> - We now do have HW init code inside cdns_ti_reset_and_init_hw().
> - It gets called at probe unconditionally and from ->runtime_resume()
> if a reset is detected (using the W1 register).
> - Auxdata patches have been reworked now that there is default auxdata
> since commit b50a2da03bd9 ("usb: cdns3-ti: Add workaround for
> Errata i2409"). We now have a patch that moves auxdata to match
> data: "usb: cdns3-ti: grab auxdata from match data".
> - cdns3/xhci: those are three new patches.
> - First, we rename "hibernated" to "lost_power" in arguments to
> the role ->resume() callbacks.
> - Then we add the xhci->lost_power flag, and only have it always copy
> the value from XHCI_RESET_ON_RESUME.
> - Finally, we set the flag from the host role driver.
> - Link to v4: https://lore.kernel.org/lkml/20240307-j7200-usb-suspend-v4-0-5ec7615431f3@xxxxxxxxxxx/
>
> Changes in v4:
> - dt-bindings: usb: ti,j721e-usb:
> - Remove ti,am64-usb single compatible entry.
> - Reverse ordering of compatible pair j721e + am64
> (becoming am64 + j721e).
> - Add j7200 + j721e compatible pair (versus only j7200). It is the
> same thing as am64: only the integration differs with base j721e
> compatible.
> - NOT taking trailers from Conor as patches changed substantially.
> - arm64: dts: ti: j3-j7200:
> - Use j7200 + j721e compatible pair (versus only j7200 previously).
> - arm64: dts: ti: j3-am64:
> - Fix to use am64 + j721e compatible pair (versus only am64).
> This is a new patch.
> - Link to v3: https://lore.kernel.org/r/20240223-j7200-usb-suspend-v3-0-b41c9893a130@xxxxxxxxxxx
>
> Changes in v3:
> - dt-bindings: use an enum to list compatibles instead of the previous
> odd construct. This is done in a separate patch from the one adding
> J7200 compatible.
> - dt-bindings: dropped Acked-by Conor as the changes were modified a lot.
> - Add runtime PM back. Put the init sequence in ->runtime_resume(). It
> gets called at probe for all compatibles and at resume for J7200.
> - Introduce a cdns_ti_match_data struct rather than rely on compatible
> from code.
> - Reorder code changes. Add infrastructure based on match data THEN add
> compatible and its match data.
> - DTSI: use only J7200 compatible rather than both J7200 then J721E.
> - Link to v2: https://lore.kernel.org/r/20231120-j7200-usb-suspend-v2-0-038c7e4a3df4@xxxxxxxxxxx
>
> Changes in v2:
> - Remove runtime PM from cdns3-ti; it brings nothing. That means our
> cdns3-ti suspend/resume patch is simpler; there is no need to handle
> runtime PM at suspend/resume.
> - Do not add cdns3 host role suspend/resume callbacks; they are not
> needed as core detects reset on resume & calls cdns_drd_host_on when
> needed.
> - cdns3-ti: Move usb2_refclk_rate_code assignment closer to the value
> computation.
> - cdns3/host.c: do not pass XHCI_SUSPEND_RESUME_CLKS quirk to xHCI; it
> is unneeded on our platform.
> - Link to v1: https://lore.kernel.org/r/20231113-j7200-usb-suspend-v1-0-ad1ee714835c@xxxxxxxxxxx
>
> ---
> Théo Lebrun (12):
> dt-bindings: usb: ti,j721e-usb: fix compatible list
> dt-bindings: usb: ti,j721e-usb: add ti,j7200-usb compatible
> usb: cdns3-ti: move reg writes to separate function
> usb: cdns3-ti: run HW init at resume() if HW was reset
> usb: cdns3: add quirk to platform data for reset-on-resume
> usb: cdns3-ti: grab auxdata from match data
> usb: cdns3-ti: add J7200 support with reset-on-resume behavior
> usb: cdns3: rename hibernated argument of role->resume() to lost_power
> xhci: introduce xhci->lost_power flag
> usb: cdns3: host: transmit lost_power signal from wrapper to XHCI
> arm64: dts: ti: k3-j7200: use J7200-specific USB compatible
> arm64: dts: ti: k3-am64: add USB fallback compatible to J721E
>
> .../devicetree/bindings/usb/ti,j721e-usb.yaml | 5 +-
> arch/arm64/boot/dts/ti/k3-am64-main.dtsi | 2 +-
> arch/arm64/boot/dts/ti/k3-j7200-main.dtsi | 2 +-
> drivers/usb/cdns3/cdns3-gadget.c | 4 +-
> drivers/usb/cdns3/cdns3-ti.c | 151 ++++++++++++++-------
> drivers/usb/cdns3/cdnsp-gadget.c | 2 +-
> drivers/usb/cdns3/core.h | 3 +-
> drivers/usb/cdns3/host.c | 13 ++
> drivers/usb/host/xhci.c | 8 +-
> drivers/usb/host/xhci.h | 6 +
> 10 files changed, 136 insertions(+), 60 deletions(-)
> ---
> base-commit: c33ffdb70cc6df4105160f991288e7d2567d7ffa
> change-id: 20240726-s2r-cdns-4b180cd960ff
>
> Best regards,
--
cheers,
-roger
