Hi Arnd, Please ignore the previous reply. On Tue, Apr 28, 2015 at 1:19 AM, Arnd Bergmann <arnd@xxxxxxxx> wrote: > On Monday 27 April 2015 21:25:20 Suman Tripathi wrote: >> > On Monday 27 April 2015 20:33:25 Suman Tripathi wrote: >> > > > On Tuesday 21 April 2015 21:12:39 Suman Tripathi wrote: >> > > > > + host->quirks |= SDHCI_QUIRK_BROKEN_DMA; >> > > > > + >> > > > > + if (of_get_property(np, "no-cmd23", NULL)) >> > > > > + host->quirks2 |= SDHCI_QUIRK2_HOST_NO_CMD23; >> > > > > >> > > > > if (of_get_property(np, "no-1-8-v", NULL)) >> > > > > >> > > > > host->quirks2 |= SDHCI_QUIRK2_NO_1_8_V; >> > > > >> > > > Any property you add needs to be documented in the DT binding. >> > > > If possible, add generic properties for each bug you have mmc.txt >> > > > rather than the driver specific sdhci.txt, and implement the >> > > >> > > I will add the binding in mmc.txt. I thought this was present but not. >> > > >> > > > parsing in a common function that is used for all mmc hosts. >> > > >> > > As per mine understanding the sdhci_get_of_porperty is a common >> > > parsing function . Am I wrong ?? >> > > A small side note: please fix your email client to use proper attribution > of the citations. The way you reply, nobody knows what you are saying > compare to what you quote. Also, reduce the quotation to the parts you > are replying to. > Okay. Sorry for that. I fixed it. >> > No, this is only used for sdhci, not for the other controllers. >> >> But our's is a SHCI variant so I added it in this file. > > That's my point: a lot of the bugs are independent of the specific > host controller and could happen with any one of them. We want to > ensure that nobody tries to add another property with similar > semantics and a different name just because they are using a > different driver. Then I am not finding a reason why we have sdhci_get_of_property function ?? . I added a generic names like broken-adma that everyone can reuse it. I made mistake of not adding it in the binding. For eg : broken-cd is not added by me but I can use it. So I added something like broken-adma as it was not present. > >> > > An alternative would be to set all these bits based on the compatible >> > > string of your host, if that is the only one that has all these bugs. >> > >> > The host driver (arasan) is reused but this quirks are needed due to >> > board issues. so I have a control over dtb only to fix this. >> >> What is the nature of the bug on that board? Is there a different >> way to describe that without introducing six new properties? >> >> Sorry it is board and IP as well SoC errata's, >> >> 1. Delay after power is required due to some voltage issues that will >> be fixed in next board revision > > This is clearly not sdhci-specific, so make that a generic property > for all mmc. > Okay >> 2. We need to support PIO mode as of now because DMA or ADMA requires >> some kind of translation driver that I am working on. > > But this does not describe the hardware properties. Don't add properties > that describe the lack of a kernel driver. If you can't do DMA yet, > use a dma-ranges property that lists one empty range to prevent > dma_set_mask() from working, so it will fall back to PIO mode. You > may have to fix the driver if that doesn't already work. > The generic sdhc framework doesn't have this capabiltiy. It uses the quirks to identify the broken DMA and ADMA modes even if the controller is capable of. > What kind of driver do you need here? For DMA and adma we need some 32 bit to 64 bit translation driver. The existing arasan driver only support 32 bit. > >> 3. The version of arasan variant we have in our SoC doesn't have the >> HISPD bit field in HI-SPEED SD card. So this makes HI-SPEED sdcard >> work. >> >> 4. NO_CMD23 is required for eMMC cards. >> >> These are not new properties. Only the fact is I am using it for our >> SoC from dtb. These quirks are already there in mmc common framework. >> Nothing is new. > > Are you sure that you have version 8.9a of the Arasan SDHCI? This sounds No We are using 4.9a ARASAN SDHCI > like version specific quirks, so they are probably present in each > SoC that uses the same version. Not sure > > Arnd -- Thanks, with regards, Suman Tripathi -- 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
