Hi Herve,
Am Mittwoch, 8. Januar 2025, 18:44:42 CET schrieb Herve Codina:
> Hi Alexander,
>
> On Wed, 08 Jan 2025 11:54:49 +0100
> Alexander Stein <alexander.stein@xxxxxxxxxxxxxxx> wrote:
>
> [...]
> > > #include <drm/drm_atomic_helper.h>
> > > #include <drm/drm_bridge.h>
> > > +#include <drm/drm_drv.h> /* DRM_MODESET_LOCK_ALL_BEGIN() needs drm_drv_uses_atomic_modeset() */
> >
> > Shouldn't this include be added to include/drm/drm_modeset_lock.h instead?
>
> Yes indeed. I will change that in the next iteration.
>
> >
> > > #include <drm/drm_mipi_dsi.h>
> > > #include <drm/drm_of.h>
> > > #include <drm/drm_panel.h>
> > > @@ -147,6 +150,9 @@ struct sn65dsi83 {
> > > struct regulator *vcc;
> > > bool lvds_dual_link;
> > > bool lvds_dual_link_even_odd_swap;
> > > + bool use_irq;
> > > + struct delayed_work monitor_work;
> > > + struct work_struct reset_work;
> >
> > Can you please rebase? You are missing commit d2b8c6d549570
> > ("drm/bridge: ti-sn65dsi83: Add ti,lvds-vod-swing optional properties")
>
> Sure, I will rebase.
>
> [...]
> > > +static void sn65dsi83_handle_errors(struct sn65dsi83 *ctx)
> > > +{
> > > + unsigned int irq_stat;
> > > + int ret;
> > > +
> > > + /*
> > > + * Schedule a reset in case of:
> > > + * - the bridge doesn't answer
> > > + * - the bridge signals an error
> > > + */
> > > +
> > > + ret = regmap_read(ctx->regmap, REG_IRQ_STAT, &irq_stat);
> > > + if (ret || irq_stat)
> > > + schedule_work(&ctx->reset_work);
> >
> > Shouldn't you clear the error bits as well?
>
> Thanks for pointing that.
>
> I can clear the error bit but further more, I probably need to simply
> disable the interrupt.
>
> In some cases, we observed i2c access failure. In that cases clearing error
> bits is simply not possible.
>
> To avoid some possible interrupt storms (the chip detect a failure, set its
> interrupt line but could be not accessible anymore), the best thing to do
> is to disable the interrupt line here, let the reset work to do its job
> performing a full reset of the device and re-enabling the interrupt line
> when needed, probably in sn65dsi83_atomic_enable().
>
> What do you think about that?
As I read the datasheet this is a active-high level interrupt, so as
long as some enabled IRQs are pending the signal will stay high.
There are 3 notes in section 9.1.3. IRQ usage that in various situations
IRQ bits may be set/pending and have to be cleared.
At least clear the interrupts before enabling it again to be on the
safe side.
Best regards,
Alexander
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