| Message ID | 20181112151853.29289-6-thierry.reding@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | serial: Add Tegra Combined UART driver | expand |
On 12/11/2018 15:18, Thierry Reding wrote: > From: Thierry Reding <treding@nvidia.com> > > Upon resuming from a system sleep state, the interrupts for all active > shared mailboxes need to be reenabled, otherwise they will not work. > > Signed-off-by: Thierry Reding <treding@nvidia.com> > --- > drivers/mailbox/tegra-hsp.c | 19 +++++++++++++++++++ > 1 file changed, 19 insertions(+) > > diff --git a/drivers/mailbox/tegra-hsp.c b/drivers/mailbox/tegra-hsp.c > index 0100a974149b..1259abf3542f 100644 > --- a/drivers/mailbox/tegra-hsp.c > +++ b/drivers/mailbox/tegra-hsp.c > @@ -18,6 +18,7 @@ > #include <linux/of.h> > #include <linux/of_device.h> > #include <linux/platform_device.h> > +#include <linux/pm.h> > #include <linux/slab.h> > > #include <dt-bindings/mailbox/tegra186-hsp.h> > @@ -817,6 +818,23 @@ static int tegra_hsp_remove(struct platform_device *pdev) > return 0; > } > > +static int tegra_hsp_resume(struct device *dev) > +{ > + struct tegra_hsp *hsp = dev_get_drvdata(dev); > + unsigned int i; > + > + for (i = 0; i < hsp->num_sm; i++) { > + struct tegra_hsp_mailbox *mb = &hsp->mailboxes[i]; > + > + if (mb->channel.chan->cl) > + tegra_hsp_mailbox_startup(mb->channel.chan); > + } > + > + return 0; > +} > + > +static SIMPLE_DEV_PM_OPS(tegra_hsp_pm_ops, NULL, tegra_hsp_resume); Is it worth disabling interrupts on suspend to avoid any in-flight interrupt triggering a bad access on entering suspend? I assume that the context of the mailbox registers get cleared/lost at some point and so I was not sure if there is a time where they have a bad state or are inaccessible? Cheers Jon
On Tue, Nov 13, 2018 at 11:17:58AM +0000, Jon Hunter wrote: > > On 12/11/2018 15:18, Thierry Reding wrote: > > From: Thierry Reding <treding@nvidia.com> > > > > Upon resuming from a system sleep state, the interrupts for all active > > shared mailboxes need to be reenabled, otherwise they will not work. > > > > Signed-off-by: Thierry Reding <treding@nvidia.com> > > --- > > drivers/mailbox/tegra-hsp.c | 19 +++++++++++++++++++ > > 1 file changed, 19 insertions(+) > > > > diff --git a/drivers/mailbox/tegra-hsp.c b/drivers/mailbox/tegra-hsp.c > > index 0100a974149b..1259abf3542f 100644 > > --- a/drivers/mailbox/tegra-hsp.c > > +++ b/drivers/mailbox/tegra-hsp.c > > @@ -18,6 +18,7 @@ > > #include <linux/of.h> > > #include <linux/of_device.h> > > #include <linux/platform_device.h> > > +#include <linux/pm.h> > > #include <linux/slab.h> > > > > #include <dt-bindings/mailbox/tegra186-hsp.h> > > @@ -817,6 +818,23 @@ static int tegra_hsp_remove(struct platform_device *pdev) > > return 0; > > } > > > > +static int tegra_hsp_resume(struct device *dev) > > +{ > > + struct tegra_hsp *hsp = dev_get_drvdata(dev); > > + unsigned int i; > > + > > + for (i = 0; i < hsp->num_sm; i++) { > > + struct tegra_hsp_mailbox *mb = &hsp->mailboxes[i]; > > + > > + if (mb->channel.chan->cl) > > + tegra_hsp_mailbox_startup(mb->channel.chan); > > + } > > + > > + return 0; > > +} > > + > > +static SIMPLE_DEV_PM_OPS(tegra_hsp_pm_ops, NULL, tegra_hsp_resume); > > Is it worth disabling interrupts on suspend to avoid any in-flight > interrupt triggering a bad access on entering suspend? I assume that the > context of the mailbox registers get cleared/lost at some point and so I > was not sure if there is a time where they have a bad state or are > inaccessible? Theoretically I think we'd have to do that. However, since we end up having to busy-loop for any current use-cases (i.e. console) anyway, we'll never end up in a situation where an interrupt could occur at this point. The console will long have been suspended when we reach this point. I'll take a look if a use-case can be constructed where such an in-flight interrupt could be produced. Thierry
diff --git a/drivers/mailbox/tegra-hsp.c b/drivers/mailbox/tegra-hsp.c index 0100a974149b..1259abf3542f 100644 --- a/drivers/mailbox/tegra-hsp.c +++ b/drivers/mailbox/tegra-hsp.c @@ -18,6 +18,7 @@ #include <linux/of.h> #include <linux/of_device.h> #include <linux/platform_device.h> +#include <linux/pm.h> #include <linux/slab.h> #include <dt-bindings/mailbox/tegra186-hsp.h> @@ -817,6 +818,23 @@ static int tegra_hsp_remove(struct platform_device *pdev) return 0; } +static int tegra_hsp_resume(struct device *dev) +{ + struct tegra_hsp *hsp = dev_get_drvdata(dev); + unsigned int i; + + for (i = 0; i < hsp->num_sm; i++) { + struct tegra_hsp_mailbox *mb = &hsp->mailboxes[i]; + + if (mb->channel.chan->cl) + tegra_hsp_mailbox_startup(mb->channel.chan); + } + + return 0; +} + +static SIMPLE_DEV_PM_OPS(tegra_hsp_pm_ops, NULL, tegra_hsp_resume); + static const struct tegra_hsp_db_map tegra186_hsp_db_map[] = { { "ccplex", TEGRA_HSP_DB_MASTER_CCPLEX, HSP_DB_CCPLEX, }, { "bpmp", TEGRA_HSP_DB_MASTER_BPMP, HSP_DB_BPMP, }, @@ -843,6 +861,7 @@ static struct platform_driver tegra_hsp_driver = { .driver = { .name = "tegra-hsp", .of_match_table = tegra_hsp_match, + .pm = &tegra_hsp_pm_ops, }, .probe = tegra_hsp_probe, .remove = tegra_hsp_remove,