On Wednesday, September 21, 2011, Yinghai Lu wrote: > On Wed, Sep 21, 2011 at 10:24 AM, Vincent Palatin <vpalatin@xxxxxxxxxxxx> wrote: > > On Mon, Sep 19, 2011 at 14:08, Rafael J. Wysocki <rjw@xxxxxxx> wrote: > >> On Monday, September 19, 2011, Vincent Palatin wrote: > >>> On Sat, Sep 17, 2011 at 09:23, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > >>> > On Fri, 16 Sep 2011, Vincent Palatin wrote: > >>> > > >>> >> When activating the PCI runtime PM on a laptop, my kernel log is filled with > >>> >> messages such as the following ones and can be hardly read to find interesting > >>> >> information: > >>> >> ehci_hcd 0000:00:1d.7: PME# disabled > >>> >> ehci_hcd 0000:00:1d.7: PCI INT A -> GSI 16 (level, low) -> IRQ 16 > >>> >> ehci_hcd 0000:00:1d.7: setting latency timer to 64 > >>> >> ehci_hcd 0000:00:1d.7: PCI INT A disabled > >>> >> ehci_hcd 0000:00:1d.7: PME# enabled > >>> >> ehci_hcd 0000:00:1d.7: BAR 0: set to [mem 0x92205000-0x922053ff] (PCI address [0x92205000-0x922053ff]) > >>> >> ehci_hcd 0000:00:1d.7: restoring config space at offset 0xf (was 0x100, writing 0x10b) > >>> >> ehci_hcd 0000:00:1d.7: restoring config space at offset 0x1 (was 0x2900000, writing 0x2900002) > >>> > ... > >>> > > >>> >> All those messages are triggered by the following cause, the laptop has a USB > >>> >> 3G modem with USB autosuspend activated. The USB device will wake up about > >>> >> every 30s to do some network related activities. Every time, the modem wakes > >>> >> up this triggers the wake up of the attached EHCI/PCI USB host controller > >>> >> which reconfigures its PCI interface, then everything go back to a suspended mode. > >>> >> > >>> >> Having the same 10 lines of log repeated is not really useful, but I probably > >>> >> cannot totally remove them since there are somewhat useful for PCI hotplug > >>> >> users and other PCI debugging. > >>> >> So, my proposal is to create a new dev_printk macro : "dev_printk_norpm" which > >>> >> outputs traces only when the device has not the runtime PM activated, > >>> >> and guard those traces with it. > >>> >> (cf the 2 patches in this thread as a PoC) > >>> > > >>> > Wouldn't it be easier just to change the existing messages to DEBUG > >>> > level? Or are they more important than that? > >>> > >>> Yes, I can simply replace all those printk by dev_dbg traces. For my > >>> use case, it's perfect. > >>> My main concern was people using PCI hotplug, I think, then, their log > >>> will remain mostly silent when inserting a card, I don't know if this > >>> is acceptable or not. > >> > >> I think they don't really need that information except for debugging, right? > > > > I think so. > > I will send a new patch with dev_dbg in replacement of the noisy > > printks for PCI messages. > > > > please use dev_printk(KERN_DEBUG,...) instead. otherwise will need > recompile the kernel with DEBUG enabled > to get debug message with debug in boot command line. Hmm? I thought that using dev_dbg() was the recommended way? Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
