Hi. On 10/17/2014 09:44 PM, Alim Akhtar wrote: > 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. I know there is no other requirement for detecting card. So this patch can be applied after testing the above case(suspend/resume). Best Regards, Jaehoon Chung >> > 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 > > > -- 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
