On Fri, Feb 21, 2025 at 10:29:48AM -0500, Yazen Ghannam wrote:

On Fri, Feb 07, 2025 at 06:18:35PM +0200, Ilpo Järvinen wrote:

quoted

PCIe r6.0 added Flit mode that mainly alters HW behavior but some OS
visible changes are also because of it. The OS visible changes include

The first sentence reads oddly. Maybe a slight change?

"...but there are some OS visible changes because of it."

Updated locally.

quoted

+	if (dev->bus && dev->bus->flit_mode)
+		flit_mode = ", in Flit mode";
+
 	if (bw_avail >= bw_cap && verbose)
-		pci_info(dev, "%u.%03u Gb/s available PCIe bandwidth (%s x%d link)\n",
+		pci_info(dev, "%u.%03u Gb/s available PCIe bandwidth (%s x%d link)%s\n",
 			 bw_cap / 1000, bw_cap % 1000,
-			 pci_speed_string(speed_cap), width_cap);
+			 pci_speed_string(speed_cap), width_cap, flit_mode);
 	else if (bw_avail < bw_cap)
-		pci_info(dev, "%u.%03u Gb/s available PCIe bandwidth, limited by %s x%d link at %s (capable of %u.%03u Gb/s with %s x%d link)\n",
+		pci_info(dev, "%u.%03u Gb/s available PCIe bandwidth, limited by %s x%d link at %s (capable of %u.%03u Gb/s with %s x%d link)%s\n",
 			 bw_avail / 1000, bw_avail % 1000,
 			 pci_speed_string(speed), width,
 			 limiting_dev ? pci_name(limiting_dev) : "<unknown>",
 			 bw_cap / 1000, bw_cap % 1000,
-			 pci_speed_string(speed_cap), width_cap);
+			 pci_speed_string(speed_cap), width_cap, flit_mode);

Does the "Flit mode" message *need* to go into these lines? Could it be
its own message?

I suppose it doesn't need to be there, and these bandwidth lines are
already pretty long (my fault, open to suggestions to shorten them),
but I do think it's useful to have related info all on the same line.

 +#include <linux/string_choices.h>

 @@ -6190,21 +6190,25 @@ void __pcie_print_link_status(struct pci_dev *dev, bool verbose)
  	enum pci_bus_speed speed, speed_cap;
  	struct pci_dev *limiting_dev = NULL;
  	u32 bw_avail, bw_cap;
  
  	bw_cap = pcie_bandwidth_capable(dev, &speed_cap, &width_cap);
  	bw_avail = pcie_bandwidth_available(dev, &limiting_dev, &speed, &width);
  
 +	if (dev->bus)
 +		pci_info(dev, "Flit mode: %s\n", str_enabled_disabled(dev->bus->flit_mode);
 +
  	if (bw_avail >= bw_cap && verbose)
 		pci_info(dev, "%u.%03u Gb/s available PCIe bandwidth (%s x%d link)\n",
  			 bw_cap / 1000, bw_cap % 1000,
 			 pci_speed_string(speed_cap), width_cap);
  	else if (bw_avail < bw_cap)
 		pci_info(dev, "%u.%03u Gb/s available PCIe bandwidth, limited by %s x%d link at %s (capable of %u.%03u Gb/s with %s x%d link)\n",
  			 bw_avail / 1000, bw_avail % 1000,
  			 pci_speed_string(speed), width,
  			 limiting_dev ? pci_name(limiting_dev) : "<unknown>",
  			 bw_cap / 1000, bw_cap % 1000,
 			 pci_speed_string(speed_cap), width_cap);

quoted

 }