Re: [PATCH] OMAPDSS: HDMI: Discard phy_tx_enabled member

Jassi Brar
2012-06-18T13:24:50Z

On 18 June 2012 18:41, Tomi Valkeinen <tomi.valkeinen@ti.com> wrote:
> On Mon, 2012-06-18 at 18:37 +0530, Jassi Brar wrote:
>> On 18 June 2012 17:54, Tomi Valkeinen <tomi.valkeinen@ti.com> wrote:
>> > On Mon, 2012-06-18 at 17:16 +0530, Jassi Brar wrote:
>>
>> >> So preferably I would move request_threaded_irq() to after
>> >> hdmi_check_hpd_state() in ti_hdmi_4xxx_phy_enable()  and convert the
>> >
>> > No, you can't move the check. If you move it, the HPD state could change
>> > between the check and the request_irq, and we'd miss it.
>> >
>> Wouldn't we then get an irq, and hence another hdmi_check_hpd_state(), for that?
>
> No, if we haven't requested the irq yet. So what could happen:
>
> - initially the cable is unplugged
> - ti_hdmi_4xxx_phy_enable() calls hdmi_check_hpd_state(), nothing is
> done as cable is unplugged
> - cable plugged in
> - ti_hdmi_4xxx_phy_enable() calls request_irq. No irq raised, as the
> cable's state doesn't change.
>
> We wouldn't know that cable is actually plugged in at that point.
>
I see, you mean physically (un)plugging the cable could race with phy_enable.

OK, I'll revise the changelog for this patch and submit another patch
converting the spinlock to mutex.

Thanks.
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