mac80211: ath11k: hack for multiple card support

This is a temporary workaround for supporting multiple cards or AHB+PCI.

There is ongoing upstream work to properly support this based of
advertised FW features, but that is still ongoing.

This is only supported on QCN9074 cards due to FW limitation, so HW ID
is checked in order to prevent breaking QCA6390 and other popular cards.

Signed-off-by: Robert Marko <robimarko@gmail.com>

1 files changed, 139 insertions, 0 deletions

diff --git a/package/kernel/mac80211/patches/ath11k/0021-wifi-ath11k-debugfs-fix-to-work-with-multiple-PCI-de.patch b/package/kernel/mac80211/patches/ath11k/0021-wifi-ath11k-debugfs-fix-to-work-with-multiple-PCI-de.patch
new file mode 100644
index 0000000000..bd72b6314b
--- /dev/null
+++ b/package/kernel/mac80211/patches/ath11k/0021-wifi-ath11k-debugfs-fix-to-work-with-multiple-PCI-de.patch
@@ -0,0 +1,139 @@
+From 323d91d4684d238f6bc3693fed93caf795378fe0 Mon Sep 17 00:00:00 2001
+From: Kalle Valo <quic_kvalo@quicinc.com>
+Date: Thu, 22 Dec 2022 19:15:59 +0200
+Subject: [PATCH] wifi: ath11k: debugfs: fix to work with multiple PCI devices
+
+ath11k fails to load if there are multiple ath11k PCI devices with same name:
+
+ ath11k_pci 0000:01:00.0: Hardware name qcn9074 hw1.0
+ debugfs: Directory 'ath11k' with parent '/' already present!
+ ath11k_pci 0000:01:00.0: failed to create ath11k debugfs
+ ath11k_pci 0000:01:00.0: failed to create soc core: -17
+ ath11k_pci 0000:01:00.0: failed to init core: -17
+ ath11k_pci: probe of 0000:01:00.0 failed with error -17
+
+Fix this by creating a directory for each ath11k device using schema
+<bus>-<devname>, for example "pci-0000:06:00.0". This directory created under
+the top-level ath11k directory, for example /sys/kernel/debug/ath11k.
+
+The reference to the toplevel ath11k directory is not stored anymore within ath11k, instead
+it's retrieved using debugfs_lookup(). If the directory does not exist it will
+be created. After the last directory from the ath11k directory is removed, for
+example when doing rmmod ath11k, the empty ath11k directory is left in place,
+it's a minor cosmetic issue anyway.
+
+Here's an example hierarchy with one WCN6855:
+
+ath11k
+`-- pci-0000:06:00.0
+    |-- mac0
+    |   |-- dfs_block_radar_events
+    |   |-- dfs_simulate_radar
+    |   |-- ext_rx_stats
+    |   |-- ext_tx_stats
+    |   |-- fw_dbglog_config
+    |   |-- fw_stats
+    |   |   |-- beacon_stats
+    |   |   |-- pdev_stats
+    |   |   `-- vdev_stats
+    |   |-- htt_stats
+    |   |-- htt_stats_reset
+    |   |-- htt_stats_type
+    |   `-- pktlog_filter
+    |-- simulate_fw_crash
+    `-- soc_dp_stats
+
+I didn't have a test setup where I could connect multiple ath11k devices to the
+same the host, so I have only tested this with one device.
+
+Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.9
+Tested-on: IPQ8074 hw2.0 AHB WLAN.HK.2.5.0.1-01208-QCAHKSWPL_SILICONZ-1
+Tested-on: QCN9074 hw1.0 PCI WLAN.HK.2.5.0.1-01208-QCAHKSWPL_SILICONZ-1
+
+Tested-by: Robert Marko <robert.marko@sartura.hr>
+Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
+Link: https://lore.kernel.org/r/20221220121231.20120-1-kvalo@kernel.org
+---
+ drivers/net/wireless/ath/ath11k/core.h    |  1 -
+ drivers/net/wireless/ath/ath11k/debugfs.c | 48 +++++++++++++++++++----
+ 2 files changed, 40 insertions(+), 9 deletions(-)
+
+--- a/drivers/net/wireless/ath/ath11k/core.h
++++ b/drivers/net/wireless/ath/ath11k/core.h
+@@ -912,7 +912,6 @@ struct ath11k_base {
+ 	enum ath11k_dfs_region dfs_region;
+ #ifdef CPTCFG_ATH11K_DEBUGFS
+ 	struct dentry *debugfs_soc;
+-	struct dentry *debugfs_ath11k;
+ #endif
+ 	struct ath11k_soc_dp_stats soc_stats;
+ 
+--- a/drivers/net/wireless/ath/ath11k/debugfs.c
++++ b/drivers/net/wireless/ath/ath11k/debugfs.c
+@@ -976,10 +976,6 @@ int ath11k_debugfs_pdev_create(struct at
+ 	if (test_bit(ATH11K_FLAG_REGISTERED, &ab->dev_flags))
+ 		return 0;
+ 
+-	ab->debugfs_soc = debugfs_create_dir(ab->hw_params.name, ab->debugfs_ath11k);
+-	if (IS_ERR(ab->debugfs_soc))
+-		return PTR_ERR(ab->debugfs_soc);
+-
+ 	debugfs_create_file("simulate_fw_crash", 0600, ab->debugfs_soc, ab,
+ 			    &fops_simulate_fw_crash);
+ 
+@@ -1001,15 +997,51 @@ void ath11k_debugfs_pdev_destroy(struct
+ 
+ int ath11k_debugfs_soc_create(struct ath11k_base *ab)
+ {
+-	ab->debugfs_ath11k = debugfs_create_dir("ath11k", NULL);
++	struct dentry *root;
++	bool dput_needed;
++	char name[64];
++	int ret;
++
++	root = debugfs_lookup("ath11k", NULL);
++	if (!root) {
++		root = debugfs_create_dir("ath11k", NULL);
++		if (IS_ERR_OR_NULL(root))
++			return PTR_ERR(root);
++
++		dput_needed = false;
++	} else {
++		/* a dentry from lookup() needs dput() after we don't use it */
++		dput_needed = true;
++	}
++
++	scnprintf(name, sizeof(name), "%s-%s", ath11k_bus_str(ab->hif.bus),
++		  dev_name(ab->dev));
++
++	ab->debugfs_soc = debugfs_create_dir(name, root);
++	if (IS_ERR_OR_NULL(ab->debugfs_soc)) {
++		ret = PTR_ERR(ab->debugfs_soc);
++		goto out;
++	}
++
++	ret = 0;
++
++out:
++	if (dput_needed)
++		dput(root);
+ 
+-	return PTR_ERR_OR_ZERO(ab->debugfs_ath11k);
++	return ret;
+ }
+ 
+ void ath11k_debugfs_soc_destroy(struct ath11k_base *ab)
+ {
+-	debugfs_remove_recursive(ab->debugfs_ath11k);
+-	ab->debugfs_ath11k = NULL;
++	debugfs_remove_recursive(ab->debugfs_soc);
++	ab->debugfs_soc = NULL;
++
++	/* We are not removing ath11k directory on purpose, even if it
++	 * would be empty. This simplifies the directory handling and it's
++	 * a minor cosmetic issue to leave an empty ath11k directory to
++	 * debugfs.
++	 */
+ }
+ EXPORT_SYMBOL(ath11k_debugfs_soc_destroy);
+