On Apr 14, 2021, at 11:08 AM, Greg KH <greg@xxxxxxxxx> wrote: > A: http://en.wikipedia.org/wiki/Top_post > Q: Were do I find info about this thing called top-posting? > A: Because it messes up the order in which people normally read text. > Q: Why is top-posting such a bad thing? > A: Top-posting. > Q: What is the most annoying thing in e-mail? > > A: No. > Q: Should I include quotations after my reply? > > http://daringfireball.net/2007/07/on_top Thanks for pointing it out:) > > On Wed, Apr 14, 2021 at 02:35:24PM +0000, Gong, Sishuai wrote: >> For now we are not sure about if this is a harmful data race or not. > > Can you please work to determine that? I found an ancient comment left in uart_set_info_user() saying mutex_lock(&port->mutex) “This semaphore protects port->count”. This is untrue since changes on port->count only grab spin_lock(&port->lock). So it looks like this needs to be fixed. > >> A potential fix could be using the same mutex lock port->mutex instead >> of port->lock, to protect every write on port->count so the reader can >> get a consistent view. However, this seems to be a big change so we >> are wondering it is worthy of this change. > > Try it out and see! We will start to think about the patch, and try to submit it after testing soon. > thanks, > > greg k-h Thanks, Sishuai
