Re: sdhci: Best Practice Question

[Chris Ball <cjb@laptop.org>]

Hi Philip,

On Sat, Sep 25, 2010 at 01:08:20PM -0700, Philip Rakity wrote:
> The change proposed by Richard Zhu for handling write protect uses 
> only a callback.
> 
> <snip>
> static int sdhci_get_ro(struct mmc_host *mmc)
> {
> 	struct sdhci_host *host;
> 	unsigned long flags;
> 	int present;
> 
> 	host = mmc_priv(mmc);
> 
> 	if (host->ops->get_ro)
> 		return host->ops->get_ro(host);
> 
> 	spin_lock_irqsave(&host->lock, flags);
> 
> <end snip>
> 
> What is the correct practice?  

I think that the get_ro hook is reasonable in this case -- we're saying
that the host has a sufficiently weird WP setup that sdhci doesn't know 
what we're supposed to do (unlike SDHCI_QUIRK_INVERTED_WRITE_PROTECT).

I'd be curious to hear what others think, though.  Should we be simply
moving away from adding new quirks, or just limiting them to cases where
a full hook isn't warranted?

-- 
Chris Ball   <cjb@laptop.org>   <http://printf.net/>
One Laptop Per Child