On Jan 11, 2008 1:17 AM, Bryan Wu <[EMAIL PROTECTED]> wrote: > On Jan 10, 2008 7:57 PM, Pierre Ossman <[EMAIL PROTECTED]> wrote: > > On Thu, 10 Jan 2008 17:22:55 +0800 > > "Bryan Wu" <[EMAIL PROTECTED]> wrote: > > > > > > > > At page 4-3 of ADSP-BF54x Blackfin(R) Processor Peripheral Hardware > > > Reference, there is a table which guide us the SDH controller does not > > > support 4-bit mode MMC card. Please found the table picture in the > > > attachment or get the document at: > > > http://www.analog.com/UploadedFiles/Associated_Docs/61460151169789ADSP_BF54x_Blackfin_Processor_Peripheral_Hardware_Reference.pdf > > > > > > > Ok, but this just means the controller wasn't designed with 4-bit MMC in > > mind. As several other "SD-only" controller have been tested with modern > > MMC cards without a problem, this is not sufficient to explain any problem. > > > > This should be some HW design issue and BF54x including SDH controller > is in mass production. > There is no chance to change the silicon, we just wanna use software > driver to workaround this issue. > So Mike's patch is here. > > > > > > > Thanks, actually we are not yet convinced by our hardware designer > > > why BF54x SDH does not support 4-bit MMC. > > > > > > > Please keep me informed on how it progresses. I'd like an at least > > plausible explanation, preferably also some empirical data, before I'm > > ready to accept Mike's patch. > > > > We were told this is an hardware design issue, so please help us to > workaround it in software side with Mike's patch. > And how do you think my suggestion to Mike's patch, > #define MMC_CAP_4_BIT_DATA ( MMC_CAP_SD_4_BIT_DATA | MMC_CAP_MMC_4_BIT_DATA) > Then no need to change other MMC host drivers
i can send an updated patch as needed. i think Bryan's suggestion here is a good one. -mike -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
