Hi, * Kevin Hilman <khilman@xxxxxx> [111108 16:23]: > Ilya Yanok <yanok@xxxxxxxxxxx> writes: > > > Bits corresponding to the IVA and ISP features in OMAP_STATUS register > > are reserved on AM35xx and checking for them results in wrong results. > > Ouch. > > > So we don't want to check for this features on AM35xx. > > > > Signed-off-by: Ilya Yanok <yanok@xxxxxxxxxxx> > > This "feature" selection mechanism is clearly not scaling to newer SoCs. > While this patch works around the problem, IMO, we need a more scalable > solution. Agreed. > For features like IVA and ISP (and SGX) which are acutally IP blocks on > the SoC, not "features" per-se, what we really need to be doing is > checking for the presence of the IP block, not checking a bit in a > register that's not consistent across various SoCs. > > We already have all the knowledge about whether the IP blocks are > present in the SoC-specific hwmod data. So checking for the "feature" > of a specific IP block should instead be done using an > omap_hwmod_lookup(). > > However, there's a bit of a snag because this "feature" detection is > currently done before the hwmods are registered. > > As a quick-and-dirty proof of concept, the patch/hack below moves the > feature checking after the hwmod init (omap3 only currently) and uses > omap_hwmod_lookup() to check whether a given IP block exists. > > I only did a quick test on one OMAP3 platform (3430/n900) and it seems > to work. The init order changes need some more thought, as I didn't > fully validate whether the feature detection can be safely moved later > for all platforms. > > This is just to show the direction we should be taking this SoC > detection for newer SoCs. This should be coordinated with the splitting of feature detection as posted by Vaibhave in thread "[RFC PATCH] arm:omap: cleanup & split omap2/3/4_check_revision function" thread. We no longer need the SoC detection super early, so I suggest we make the feature detection separate from SoC detection. The SoC specific init can then call: omap3_check_revision(); ti816x_check_features(); Regards, Tony -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
