From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: Date: Mon, 22 Aug 2016 17:15:36 -0400 From: Keith Busch To: Bjorn Helgaas Cc: linux-pci@vger.kernel.org, Bjorn Helgaas Subject: Re: [PATCH 2/2] pci: Add ignore indicator quirk for devices Message-ID: <20160822211536.GE28276@localhost.localdomain> References: <1470687542-30155-1-git-send-email-keith.busch@intel.com> <1470687542-30155-2-git-send-email-keith.busch@intel.com> <20160815174002.GB9790@localhost> <20160815192316.GB18083@localhost.localdomain> <20160817213745.GE27353@localhost> <20160817230951.GD25146@localhost.localdomain> <20160818195656.GH27353@localhost> <20160818224610.GA28276@localhost.localdomain> <20160822165524.GC18628@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20160822165524.GC18628@localhost> List-ID: On Mon, Aug 22, 2016 at 11:55:24AM -0500, Bjorn Helgaas wrote: > I was imagining these LEDs as some sort of extension to the PCIe > hotplug model, but I think that was a mistake: logically, they have > nothing to do with hotplug, and the only reason they're currently > associated with hotplug is because you chose to re-use a bus (VPP) > that happens to be connected to the Slot Control registers. > > From an architectural point of view, these LEDs seem device-specific > or storage-specific, with no connection to PCIe at all, so I don't > know why we would put them in the PCIe spec or teach pciehp about > them. It's not entirely for hotplug scenarios, but it does help with user pain points locating devices they intend to hot remove. I hear many vendors are for the concept of proposing new status and location indicator definitions to PCIe. I don't think anyone is suggesting the implementation requiring this patch be made standard; this generation of hardware is just a non-standard implementation that needs a quirk to help fill the gap. Would it be more palatable if I modify the quirk such that when set, pciehp provides a sysfs entry allowing arbitrary user defined Slot Control commands? That removes the dangerous direct access from user space.