On Thu, Oct 03, 2019 at 02:41:11PM +0000, mario.limoncie...@dell.com wrote: > > -----Original Message----- > > From: Mika Westerberg <mika.westerb...@linux.intel.com> > > Sent: Thursday, October 3, 2019 3:00 AM > > To: Limonciello, Mario > > Cc: yehezkel...@gmail.com; linux-...@vger.kernel.org; > > andreas.noe...@gmail.com; michael.ja...@intel.com; > > rajmohan.m...@intel.com; nicholas.johnson-opensou...@outlook.com.au; > > lu...@wunner.de; gre...@linuxfoundation.org; st...@rowland.harvard.edu; > > anthony.w...@canonical.com; linux-kernel@vger.kernel.org > > Subject: Re: [RFC PATCH 17/22] thunderbolt: Add initial support for USB4 > > > > > > [EXTERNAL EMAIL] > > > > On Wed, Oct 02, 2019 at 04:00:55PM +0000, mario.limoncie...@dell.com wrote: > > > > It's not even "same location - another meaning", the vendor ID comes > > > > from > > the > > > > DROM section, so it takes a few internal jumps inside the NVM to find > > > > the > > > > location. One of the "pointers" or section headers will be broken for > > > > sure. > > > > > > > > And after this, we need to find the NVM in LVFS and it has to pass > > > > validation > > in > > > > a few other locations. The chances are so low that I'd think it isn't > > > > worth > > > > worrying about it. > > > > > > And now I remember why the back of my mind was having this thought of > > wanting > > > sysfs attribute in the first place. The multiple jumps means that a lot > > > more of > > the > > > NVM has to be dumped to get that data, which slows down fwupd startup > > significantly. > > > > IIRC currently fwupd does two reads of total 128 bytes from the active > > NVM. Is that really slowing down fwupd startup significantly? > > Yeah, I timed it with fwupd. Here's the averages: > > Without doing the reads to jump to this it's 0:00.06 seconds to probe a tree > of > Host controller and dock plugged in. > > With doing the reads and just host controller: > 0:04.40 seconds > > With doing the reads and host controller and dock plugged in: > 0:10.73 seconds
OK, it clearly takes time to read them. I wonder if this includes powering up the controller? Also if you can get the hw_vendor_id and hw_product_id from the kernel does that mean you don't need to do the two reads or you still need those?
