| Message ID | 1308862842-3933-7-git-send-email-b-cousson@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Benoit Cousson |
| Headers | show |
One quick comment here: On Thu, 23 Jun 2011, Benoit Cousson wrote: > The HW reset must be de-assert after the clocks are enabled > but before waiting for the target to be ready. Otherwise the > reset might not work properly since the clock is not running > to proceed the reset. > > De-assert the reset after _enable_clocks and before > _wait_target_ready. > Re-assert it only when the clocks are disabled. > > Signed-off-by: Benoit Cousson <b-cousson@ti.com> > Cc: Paul Walmsley <paul@pwsan.com> > --- > arch/arm/mach-omap2/omap_hwmod.c | 32 ++++++++++++++++---------------- > 1 files changed, 16 insertions(+), 16 deletions(-) > > diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c > index f401417..55ad6a5 100644 > --- a/arch/arm/mach-omap2/omap_hwmod.c > +++ b/arch/arm/mach-omap2/omap_hwmod.c > @@ -1250,15 +1250,6 @@ static int _enable(struct omap_hwmod *oh) > > pr_debug("omap_hwmod: %s: enabling\n", oh->name); > > - /* > - * If an IP contains only one HW reset line, then de-assert it in order > - * to allow to enable the clocks. Otherwise the PRCM will return > - * Intransition status, and the init will failed. > - */ > - if ((oh->_state == _HWMOD_STATE_INITIALIZED || > - oh->_state == _HWMOD_STATE_DISABLED) && oh->rst_lines_cnt == 1) > - _deassert_hardreset(oh, oh->rst_lines[0].name); > - > /* Mux pins for device runtime if populated */ > if (oh->mux && (!oh->mux->enabled || > ((oh->_state == _HWMOD_STATE_IDLE) && > @@ -1268,6 +1259,15 @@ static int _enable(struct omap_hwmod *oh) > _add_initiator_dep(oh, mpu_oh); > _enable_clocks(oh); > > + /* > + * If an IP contains only one HW reset line, then de-assert it in order > + * to allow to enable the clocks. Otherwise the PRCM will return > + * Intransition status, and the init will failed. > + */ Please update this comment, this doesn't make sense any more... > + if ((oh->_state == _HWMOD_STATE_INITIALIZED || > + oh->_state == _HWMOD_STATE_DISABLED) && oh->rst_lines_cnt == 1) > + _deassert_hardreset(oh, oh->rst_lines[0].name); > + > r = _wait_target_ready(oh); > if (!r) { > oh->_state = _HWMOD_STATE_ENABLED; > @@ -1396,13 +1396,6 @@ static int _shutdown(struct omap_hwmod *oh) > _shutdown_sysc(oh); > } > > - /* > - * If an IP contains only one HW reset line, then assert it > - * before disabling the clocks and shutting down the IP. > - */ > - if (oh->rst_lines_cnt == 1) > - _assert_hardreset(oh, oh->rst_lines[0].name); > - > /* clocks and deps are already disabled in idle */ > if (oh->_state == _HWMOD_STATE_ENABLED) { > _del_initiator_dep(oh, mpu_oh); > @@ -1411,6 +1404,13 @@ static int _shutdown(struct omap_hwmod *oh) > } > /* XXX Should this code also force-disable the optional clocks? */ > > + /* > + * If an IP contains only one HW reset line, then assert it > + * before disabling the clocks and shutting down the IP. > + */ And this one too. > + if (oh->rst_lines_cnt == 1) > + _assert_hardreset(oh, oh->rst_lines[0].name); > + > /* Mux pins to safe mode or use populated off mode values */ > if (oh->mux) > omap_hwmod_mux(oh->mux, _HWMOD_STATE_DISABLED); > -- > 1.7.0.4 > - Paul -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 7/1/2011 10:44 AM, Paul Walmsley wrote: > One quick comment here: > > On Thu, 23 Jun 2011, Benoit Cousson wrote: > >> The HW reset must be de-assert after the clocks are enabled >> but before waiting for the target to be ready. Otherwise the >> reset might not work properly since the clock is not running >> to proceed the reset. >> >> De-assert the reset after _enable_clocks and before >> _wait_target_ready. >> Re-assert it only when the clocks are disabled. >> >> Signed-off-by: Benoit Cousson<b-cousson@ti.com> >> Cc: Paul Walmsley<paul@pwsan.com> >> --- >> arch/arm/mach-omap2/omap_hwmod.c | 32 ++++++++++++++++---------------- >> 1 files changed, 16 insertions(+), 16 deletions(-) >> >> diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c >> index f401417..55ad6a5 100644 >> --- a/arch/arm/mach-omap2/omap_hwmod.c >> +++ b/arch/arm/mach-omap2/omap_hwmod.c >> @@ -1250,15 +1250,6 @@ static int _enable(struct omap_hwmod *oh) >> >> pr_debug("omap_hwmod: %s: enabling\n", oh->name); >> >> - /* >> - * If an IP contains only one HW reset line, then de-assert it in order >> - * to allow to enable the clocks. Otherwise the PRCM will return >> - * Intransition status, and the init will failed. >> - */ >> - if ((oh->_state == _HWMOD_STATE_INITIALIZED || >> - oh->_state == _HWMOD_STATE_DISABLED)&& oh->rst_lines_cnt == 1) >> - _deassert_hardreset(oh, oh->rst_lines[0].name); >> - >> /* Mux pins for device runtime if populated */ >> if (oh->mux&& (!oh->mux->enabled || >> ((oh->_state == _HWMOD_STATE_IDLE)&& >> @@ -1268,6 +1259,15 @@ static int _enable(struct omap_hwmod *oh) >> _add_initiator_dep(oh, mpu_oh); >> _enable_clocks(oh); >> >> + /* >> + * If an IP contains only one HW reset line, then de-assert it in order >> + * to allow to enable the clocks. Otherwise the PRCM will return >> + * Intransition status, and the init will failed. >> + */ > > Please update this comment, this doesn't make sense any more... Good point, I'll fix that. > >> + if ((oh->_state == _HWMOD_STATE_INITIALIZED || >> + oh->_state == _HWMOD_STATE_DISABLED)&& oh->rst_lines_cnt == 1) >> + _deassert_hardreset(oh, oh->rst_lines[0].name); >> + >> r = _wait_target_ready(oh); >> if (!r) { >> oh->_state = _HWMOD_STATE_ENABLED; >> @@ -1396,13 +1396,6 @@ static int _shutdown(struct omap_hwmod *oh) >> _shutdown_sysc(oh); >> } >> >> - /* >> - * If an IP contains only one HW reset line, then assert it >> - * before disabling the clocks and shutting down the IP. >> - */ >> - if (oh->rst_lines_cnt == 1) >> - _assert_hardreset(oh, oh->rst_lines[0].name); >> - >> /* clocks and deps are already disabled in idle */ >> if (oh->_state == _HWMOD_STATE_ENABLED) { >> _del_initiator_dep(oh, mpu_oh); >> @@ -1411,6 +1404,13 @@ static int _shutdown(struct omap_hwmod *oh) >> } >> /* XXX Should this code also force-disable the optional clocks? */ >> >> + /* >> + * If an IP contains only one HW reset line, then assert it >> + * before disabling the clocks and shutting down the IP. >> + */ > > And this one too. OK. Benoit -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c index f401417..55ad6a5 100644 --- a/arch/arm/mach-omap2/omap_hwmod.c +++ b/arch/arm/mach-omap2/omap_hwmod.c @@ -1250,15 +1250,6 @@ static int _enable(struct omap_hwmod *oh) pr_debug("omap_hwmod: %s: enabling\n", oh->name); - /* - * If an IP contains only one HW reset line, then de-assert it in order - * to allow to enable the clocks. Otherwise the PRCM will return - * Intransition status, and the init will failed. - */ - if ((oh->_state == _HWMOD_STATE_INITIALIZED || - oh->_state == _HWMOD_STATE_DISABLED) && oh->rst_lines_cnt == 1) - _deassert_hardreset(oh, oh->rst_lines[0].name); - /* Mux pins for device runtime if populated */ if (oh->mux && (!oh->mux->enabled || ((oh->_state == _HWMOD_STATE_IDLE) && @@ -1268,6 +1259,15 @@ static int _enable(struct omap_hwmod *oh) _add_initiator_dep(oh, mpu_oh); _enable_clocks(oh); + /* + * If an IP contains only one HW reset line, then de-assert it in order + * to allow to enable the clocks. Otherwise the PRCM will return + * Intransition status, and the init will failed. + */ + if ((oh->_state == _HWMOD_STATE_INITIALIZED || + oh->_state == _HWMOD_STATE_DISABLED) && oh->rst_lines_cnt == 1) + _deassert_hardreset(oh, oh->rst_lines[0].name); + r = _wait_target_ready(oh); if (!r) { oh->_state = _HWMOD_STATE_ENABLED; @@ -1396,13 +1396,6 @@ static int _shutdown(struct omap_hwmod *oh) _shutdown_sysc(oh); } - /* - * If an IP contains only one HW reset line, then assert it - * before disabling the clocks and shutting down the IP. - */ - if (oh->rst_lines_cnt == 1) - _assert_hardreset(oh, oh->rst_lines[0].name); - /* clocks and deps are already disabled in idle */ if (oh->_state == _HWMOD_STATE_ENABLED) { _del_initiator_dep(oh, mpu_oh); @@ -1411,6 +1404,13 @@ static int _shutdown(struct omap_hwmod *oh) } /* XXX Should this code also force-disable the optional clocks? */ + /* + * If an IP contains only one HW reset line, then assert it + * before disabling the clocks and shutting down the IP. + */ + if (oh->rst_lines_cnt == 1) + _assert_hardreset(oh, oh->rst_lines[0].name); + /* Mux pins to safe mode or use populated off mode values */ if (oh->mux) omap_hwmod_mux(oh->mux, _HWMOD_STATE_DISABLED);
The HW reset must be de-assert after the clocks are enabled but before waiting for the target to be ready. Otherwise the reset might not work properly since the clock is not running to proceed the reset. De-assert the reset after _enable_clocks and before _wait_target_ready. Re-assert it only when the clocks are disabled. Signed-off-by: Benoit Cousson <b-cousson@ti.com> Cc: Paul Walmsley <paul@pwsan.com> --- arch/arm/mach-omap2/omap_hwmod.c | 32 ++++++++++++++++---------------- 1 files changed, 16 insertions(+), 16 deletions(-)