Hi Doug, On Thu, Oct 16, 2014 at 9:40 PM, Doug Anderson <dianders@xxxxxxxxxxxx> wrote: > Alim, > > On Thu, Oct 16, 2014 at 5:57 AM, Alim Akhtar <alim.akhtar@xxxxxxxxx> wrote: >> Hi Doug, >> >> On Tue, Oct 14, 2014 at 10:03 PM, Doug Anderson <dianders@xxxxxxxxxxxx> wrote: >>> The dw_mmc driver had a bunch of code that ran whenever a card was >>> ejected and inserted. However, this code was old and crufty and >>> should be removed. Some evidence that it's really not needed: >>> >>> 1. Is is supposed to be legal to use 'cd-gpio' on dw_mmc instead of >>> using the built-in card detect mechanism. The 'cd-gpio' code >>> doesn't run any of the crufty old code but yet still works. >>> >>> 2. While looking at this, I realized that my old change (369ac86 mmc: >>> dw_mmc: don't queue up a card detect at slot startup) actually >>> castrated the old code a little bit already and nobody noticed. >>> Specifically "last_detect_state" was left as 0 at bootup. That >>> means that on the first card removal none of the crufty code ran. >>> >> Yes, right most of these codes are _almost_ never call. But I see >> dw_mci_reset() being called on card removal (after first >> insert/removal). > > Right. The old crufty code was called on the 2nd removal, not the > 1st. That meant that the two were accidentally different. My point > was that if the old code was really required that someone would have > noticed crashes on the 1st removal after each boot. Since nobody is > reporting crashes with that then it means it can't be too terrible. > > One thing to note: I remember in the last Chromebook project you were > trying to track down crashes associated with constant eject / insert > of SD Cards. I wonder if my patch will fix these crashes? > Ah, yes, reproducing that and checking with this patch will be really interesting. > >> I tested this on exynos5800 and this looks working fine. We need to >> test once cross suspend/resume as well. > > Good idea. Can you test that? I know that there's been lots of flux > with suspend/resume on exynos and I'm not sure I have all the latest > patches, but I'll search for them if you are unable to test easily. > Sure, I will do that..but probably sometime next week, as I will out of office for few days. > >> And as Jaehoon pointed out,probably lets look in TRM if there are some >> recommended steps for cd-detect. >> Otherwise this looks good to me. > > If you see some other requirement than the one I addressed in my email > to Jaehoon, please let me know. > Well, as most of the current CD detect code are dead code, so lets see more test results, specially across a suspend/resume and warm reboot test and take this forward. > > -Doug -- Regards, Alim -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
