Messages in this thread | | | Subject | Re: [PATCH] extcon: extcon-axp288: use low level P-Unit semaphore lock for axp288 register accesses | From | Hans de Goede <> | Date | Thu, 9 Sep 2021 18:20:49 +0200 |
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Hi All,
On 9/9/21 5:18 PM, Fabio Aiuto wrote: > use low level P-Unit semaphore lock for axp288 register > accesses directly and for more than one access a time, > to reduce the number of times this semaphore is locked > and released which is an expensive operation. > > i2c-bus to the XPower is shared between the kernel and the > SoCs P-Unit. The P-Unit has a semaphore wich the kernel must > lock for axp288 register accesses. When the P-Unit semaphore > is locked CPU and GPU power states cannot change or the system > will freeze. > > The P-Unit semaphore lock is already managed inside the regmap > access logic, but for each access the semaphore is locked and > released. So use directly iosf_mbi_(un)block_punit_i2c_access(), > we are safe in doing so because nested calls to the same > semaphore are turned to nops. > > Suggested-by: Hans de Goede <hdegoede@redhat.com> > Signed-off-by: Fabio Aiuto <fabioaiuto83@gmail.com>
Thanks, patch looks good to me:
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
I've also given it a test run on a Chuwi Hibook which uses this PMIC:
Tested-by: Hans de Goede <hdegoede@redhat.com>
Regards,
Hans
> --- > drivers/extcon/extcon-axp288.c | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/drivers/extcon/extcon-axp288.c b/drivers/extcon/extcon-axp288.c > index fdb31954cf2b..460402b14ef2 100644 > --- a/drivers/extcon/extcon-axp288.c > +++ b/drivers/extcon/extcon-axp288.c > @@ -24,6 +24,7 @@ > > #include <asm/cpu_device_id.h> > #include <asm/intel-family.h> > +#include <asm/iosf_mbi.h> > > /* Power source status register */ > #define PS_STAT_VBUS_TRIGGER BIT(0) > @@ -215,6 +216,8 @@ static int axp288_handle_chrg_det_event(struct axp288_extcon_info *info) > unsigned int cable = info->previous_cable; > bool vbus_attach = false; > > + iosf_mbi_block_punit_i2c_access(); > + > vbus_attach = axp288_get_vbus_attach(info); > if (!vbus_attach) > goto no_vbus; > @@ -253,6 +256,8 @@ static int axp288_handle_chrg_det_event(struct axp288_extcon_info *info) > } > > no_vbus: > + iosf_mbi_unblock_punit_i2c_access(); > + > extcon_set_state_sync(info->edev, info->previous_cable, false); > if (info->previous_cable == EXTCON_CHG_USB_SDP) > extcon_set_state_sync(info->edev, EXTCON_USB, false); > @@ -275,6 +280,8 @@ static int axp288_handle_chrg_det_event(struct axp288_extcon_info *info) > return 0; > > dev_det_ret: > + iosf_mbi_unblock_punit_i2c_access(); > + > if (ret < 0) > dev_err(info->dev, "failed to detect BC Mod\n"); > > @@ -307,11 +314,14 @@ static irqreturn_t axp288_extcon_isr(int irq, void *data) > > static void axp288_extcon_enable(struct axp288_extcon_info *info) > { > + iosf_mbi_block_punit_i2c_access(); > regmap_update_bits(info->regmap, AXP288_BC_GLOBAL_REG, > BC_GLOBAL_RUN, 0); > /* Enable the charger detection logic */ > regmap_update_bits(info->regmap, AXP288_BC_GLOBAL_REG, > BC_GLOBAL_RUN, BC_GLOBAL_RUN); > + > + iosf_mbi_unblock_punit_i2c_access(); > } > > static void axp288_put_role_sw(void *data) > @@ -384,10 +394,14 @@ static int axp288_extcon_probe(struct platform_device *pdev) > } > } > > + iosf_mbi_block_punit_i2c_access(); > + > info->vbus_attach = axp288_get_vbus_attach(info); > > axp288_extcon_log_rsi(info); > > + iosf_mbi_unblock_punit_i2c_access(); > + > /* Initialize extcon device */ > info->edev = devm_extcon_dev_allocate(&pdev->dev, > axp288_extcon_cables); >
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