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

On 18 June 2012 16:24, Tomi Valkeinen [off-list ref] wrote:

On Mon, 2012-06-18 at 15:42 +0530, Jassi Brar wrote:

quoted

BTW, coming to think about it, I am not sure what we need the
spin_lock_irqsave() protection for in hdmi_check_hpd_state() ?  It
can't control HPD gpio state change and hdmi_set_phy_pwr() seems too
expensive and is already unprotected elsewhere.

It's needed when enabling the hdmi output. In phy_enable() the irq is
requested first, and then the phy_enable() runs hdmi_check_hpd_state().
So there's a chance to run hdmi_check_hpd_state() from both
hpd-interrupt and phy_enable() at the same time.

The hdmi_set_phy_pwr() is not called in many places, but I think there's
indeed a problem there. It is called after free_irq(), but I think
(guess) the irq handler could still be running after free_irq. So those
should be protected by the same spinlock too.

You know TI HDMI better than I do, so I assume your concerns are valid.
So preferably I would move request_threaded_irq() to after
hdmi_check_hpd_state() in ti_hdmi_4xxx_phy_enable()  and convert the
spin_lock_irqsave() in hdmi_check_hpd_state() to some mutex (we don't
want irqs disabled so long as it takes for phy to power on/off).