On 02/08/2017 06:04 PM, Timur Tabi wrote: > On 02/08/2017 04:22 PM, Christopher Covington wrote: >>>> >> - while (pl011_read(uap, REG_FR) & uap->vendor->fr_busy) >>>> >> + while ((pl011_read(uap, REG_FR) ^ uap->vendor->inv_fr) >>>> >> + & uap->vendor->fr_busy) >>> > >>> > I really think the XOR logic needs to be documented wherever it's >>> > used. It's just too confusing. >> References such as the following for basic bit operations like >> setting, clearing, and toggling are easy enough to come by. >> >> http://stackoverflow.com/questions/47981/how-do-you-set-clear-and-toggle-a-single-bit-in-c-c > > I know what XOR does. I was thinking a more high-level comment would > be appropriate. With E44, we want to ignore the BUSY bit and use TXFE > instead. So was hoping to a comment that says that: > > /* Normally, we poll until BUSY=0, but E44 says we should poll until > TXFE=1 instead. So with E44, we set fr_busy to TXFE, but we have to > invert it. */ Oh, yeah, that'd be good. I'll include better comments in v2. Cheers, Cov -- Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project. -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
