On 2 August 2014 02:06, Schollmeyer, David A <david.a.schollmeyer@xxxxxxxxx> wrote: > > I have a card with BKOPS_SUPPORT set in its ext_csd and I see the > following Message during boot: > > mmc0: BKOPS_EN bit is not set. > > From the eMMC spec, it looks to me that the host should set this bit > if the card reports BKOPS_SUPPORT: > > 7.4.60 BKOPS_EN [163] > This field allows the host to indicate to the device if it is > expected to periodically manually start background operations by > writing to the BKOPS_START field. > > Am I reading this correctly? Shouldn't the mmc driver write the > register after reading the ext_csd if it wishes to perform background > operations and the card supports it? > Historically we have maintained a policy of not allowing the mmc driver automatically to write register bits that is one time programmable. Instead those have to be "manually" written, typically using the the mmc ioctl cmd or some other tool in the production phase of a platform. If I remember correctly the BKOPS_EN bit is a one time programmable bit, right!? Kind regards Uffe -- 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
