| Message ID | 20211112162827.128319-2-aouledameur@baylibre.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | usb: meson: fix shared reset control use | expand |
On Fri, Nov 12, 2021 at 5:33 PM Amjad Ouled-Ameur <aouledameur@baylibre.com> wrote: > > Use reset_control_rearm() call if an error occurs in case > phy_meson_gxl_usb2_init() fails after reset() has been called ; or in case > phy_meson_gxl_usb2_exit() is called i.e the resource is no longer used > and the reset line may be triggered again by other devices. > > reset_control_rearm() keeps use of triggered_count sane in the reset > framework. Therefore, use of reset_control_reset() on shared reset line > should be balanced with reset_control_rearm(). > > Signed-off-by: Amjad Ouled-Ameur <aouledameur@baylibre.com> > Reported-by: Jerome Brunet <jbrunet@baylibre.com> Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Hi Amjad, On Fri, 2021-11-12 at 17:28 +0100, Amjad Ouled-Ameur wrote: > Use reset_control_rearm() call if an error occurs in case > phy_meson_gxl_usb2_init() fails after reset() has been called ; or in case > phy_meson_gxl_usb2_exit() is called i.e the resource is no longer used > and the reset line may be triggered again by other devices. > > reset_control_rearm() keeps use of triggered_count sane in the reset > framework. Therefore, use of reset_control_reset() on shared reset line > should be balanced with reset_control_rearm(). > > Signed-off-by: Amjad Ouled-Ameur <aouledameur@baylibre.com> > Reported-by: Jerome Brunet <jbrunet@baylibre.com> > --- > drivers/phy/amlogic/phy-meson-gxl-usb2.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/phy/amlogic/phy-meson-gxl-usb2.c b/drivers/phy/amlogic/phy-meson-gxl-usb2.c > index 2b3c0d730f20..9a9c769ecabc 100644 > --- a/drivers/phy/amlogic/phy-meson-gxl-usb2.c > +++ b/drivers/phy/amlogic/phy-meson-gxl-usb2.c > @@ -110,8 +110,10 @@ static int phy_meson_gxl_usb2_init(struct phy *phy) > int ret; > > ret = reset_control_reset(priv->reset); > - if (ret) > + if (ret) { > + reset_control_rearm(priv->reset); I don't understand this. If reset_control_reset() returns an error for a shared reset, it should have either - returned before incrementing triggered_count, or - incremented triggered_count, got a failed reset op, decremented triggered_count again In both cases there should be no need to rearm. regards Philipp
Hi Philipp, Thank you for the review. On 22/11/2021 10:03, Philipp Zabel wrote: > Hi Amjad, > > On Fri, 2021-11-12 at 17:28 +0100, Amjad Ouled-Ameur wrote: >> Use reset_control_rearm() call if an error occurs in case >> phy_meson_gxl_usb2_init() fails after reset() has been called ; or in case >> phy_meson_gxl_usb2_exit() is called i.e the resource is no longer used >> and the reset line may be triggered again by other devices. >> >> reset_control_rearm() keeps use of triggered_count sane in the reset >> framework. Therefore, use of reset_control_reset() on shared reset line >> should be balanced with reset_control_rearm(). >> >> Signed-off-by: Amjad Ouled-Ameur <aouledameur@baylibre.com> >> Reported-by: Jerome Brunet <jbrunet@baylibre.com> >> --- >> drivers/phy/amlogic/phy-meson-gxl-usb2.c | 5 ++++- >> 1 file changed, 4 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/phy/amlogic/phy-meson-gxl-usb2.c b/drivers/phy/amlogic/phy-meson-gxl-usb2.c >> index 2b3c0d730f20..9a9c769ecabc 100644 >> --- a/drivers/phy/amlogic/phy-meson-gxl-usb2.c >> +++ b/drivers/phy/amlogic/phy-meson-gxl-usb2.c >> @@ -110,8 +110,10 @@ static int phy_meson_gxl_usb2_init(struct phy *phy) >> int ret; >> >> ret = reset_control_reset(priv->reset); >> - if (ret) >> + if (ret) { >> + reset_control_rearm(priv->reset); > I don't understand this. If reset_control_reset() returns an error for a > shared reset, it should have either > - returned before incrementing triggered_count, or > - incremented triggered_count, got a failed reset op, decremented > triggered_count again > > In both cases there should be no need to rearm. > I have checked this out and I agree with you, will remove this in next version. Thank you for spotting this. Regards, Amjad > regards > Philipp
diff --git a/drivers/phy/amlogic/phy-meson-gxl-usb2.c b/drivers/phy/amlogic/phy-meson-gxl-usb2.c index 2b3c0d730f20..9a9c769ecabc 100644 --- a/drivers/phy/amlogic/phy-meson-gxl-usb2.c +++ b/drivers/phy/amlogic/phy-meson-gxl-usb2.c @@ -110,8 +110,10 @@ static int phy_meson_gxl_usb2_init(struct phy *phy) int ret; ret = reset_control_reset(priv->reset); - if (ret) + if (ret) { + reset_control_rearm(priv->reset); return ret; + } ret = clk_prepare_enable(priv->clk); if (ret) @@ -125,6 +127,7 @@ static int phy_meson_gxl_usb2_exit(struct phy *phy) struct phy_meson_gxl_usb2_priv *priv = phy_get_drvdata(phy); clk_disable_unprepare(priv->clk); + reset_control_rearm(priv->reset); return 0; }
Use reset_control_rearm() call if an error occurs in case phy_meson_gxl_usb2_init() fails after reset() has been called ; or in case phy_meson_gxl_usb2_exit() is called i.e the resource is no longer used and the reset line may be triggered again by other devices. reset_control_rearm() keeps use of triggered_count sane in the reset framework. Therefore, use of reset_control_reset() on shared reset line should be balanced with reset_control_rearm(). Signed-off-by: Amjad Ouled-Ameur <aouledameur@baylibre.com> Reported-by: Jerome Brunet <jbrunet@baylibre.com> --- drivers/phy/amlogic/phy-meson-gxl-usb2.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)