Re: [PATCH 1/7] mmc: mxs-mmc: add mmc host driver for i.MX23/28

Shawn Guo
2011-02-13T09:53:57Z

Hi Arnd,

On Fri, Feb 11, 2011 at 08:35:34AM +0800, Shawn Guo wrote:
>
> > > + unsigned present:1;
> >
> > Your card detection by polling through this variable is
> > really bad for power management. Is there really no interrupt
> > that gets triggered when installing or removing a card?
> >
> Good point. Will try to use interrupt.
>
I'm trying to use interrupt for card detection. But unfortunately,
I got stuck for some reason.

There is a known issue that mx28 gpio interrupt from bank0 can not
work, because the pin bank0 irq number 127 was used in
get_irqnr_and_base (entry-macro.S) to tell there is no pending
interrupt any more.

The mmc0 cd pin has no problem to trigger interrupt, as it's GPIO_2_9.
But mmc1 cd pin can not, because it's GPIO_0_20.

So I probably have to stay with polling.

Regards,
Shawn