Re: [PATCH v8 4/5] reset: rzv2h-usb2phy: Keep PHY clock enabled for entire device lifetime
From: Tommaso Merciai
Date: Thu Mar 26 2026 - 13:24:48 EST
Hi Philipp,
Thanks for your review.
On Thu, Mar 12, 2026 at 04:24:28PM +0100, Philipp Zabel wrote:
> On Do, 2026-03-12 at 15:50 +0100, Tommaso Merciai wrote:
> > The driver was disabling the USB2 PHY clock immediately after register
> > initialization in probe() and after each reset operation. This left the
> > PHY unclocked even though it must remain active for USB functionality.
> >
> > The behavior appeared to work only when another driver
> > (e.g., USB controller) had already enabled the clock, making operation
> > unreliable and hardware-dependent. In configurations where this driver
> > is the sole clock user, USB functionality would fail.
> >
> > Fix this by:
> > - Enabling the clock once in probe() via pm_runtime_resume_and_get()
> > - Removing all pm_runtime_put() calls from assert/deassert/status
> > - Registering a devm cleanup action to release the clock at removal
> > - Removed rzv2h_usbphy_assert_helper() and its call in
> > rzv2h_usb2phy_reset_probe()
> >
> > This ensures the PHY clock remains enabled for the entire device lifetime,
> > preventing instability and aligning with hardware requirements.
> >
> > Cc: stable@xxxxxxxxxxxxxxx
> > Fixes: e3911d7f865b ("reset: Add USB2PHY port reset driver for Renesas RZ/V2H(P)")
> > Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@xxxxxxxxxxxxxx>
>
> Given the Cc: stable tag I assume I can apply this first, independently
> of the other patches?
Yes, Thanks for asking.
Kind Regards,
Tommaso
>
> Reviewed-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
>
> regards
> Philipp