1 files changed, 104 insertions, 0 deletions
diff --git a/package/kernel/mac80211/patches/303-ath10k-do-not-use-coherent-memory-for-allocated-devi.patch b/package/kernel/mac80211/patches/303-ath10k-do-not-use-coherent-memory-for-allocated-devi.patch
new file mode 100644
index 0000000..20bece6
--- /dev/null
+++ b/package/kernel/mac80211/patches/303-ath10k-do-not-use-coherent-memory-for-allocated-devi.patch
@@ -0,0 +1,104 @@
+From: Felix Fietkau <nbd@openwrt.org>
+Date: Sun, 22 Nov 2015 14:03:40 +0100
+Subject: [PATCH] ath10k: do not use coherent memory for allocated device
+ memory chunks
+
+Coherent memory is more expensive to allocate (and constrained on some
+architectures where it has to be pre-allocated). It is also completely
+unnecessary, since the host has no reason to even access these allocated
+memory spaces
+
+Signed-off-by: Felix Fietkau <nbd@openwrt.org>
+---
+
+--- a/drivers/net/wireless/ath/ath10k/wmi.c
++++ b/drivers/net/wireless/ath/ath10k/wmi.c
+@@ -4312,34 +4312,58 @@ void ath10k_wmi_event_vdev_resume_req(st
+ 	ath10k_dbg(ar, ATH10K_DBG_WMI, "WMI_VDEV_RESUME_REQ_EVENTID\n");
+ }
+ 
+-static int ath10k_wmi_alloc_host_mem(struct ath10k *ar, u32 req_id,
+-				     u32 num_units, u32 unit_len)
++static int ath10k_wmi_alloc_chunk(struct ath10k *ar, u32 req_id,
++				  u32 num_units, u32 unit_len)
+ {
+ 	dma_addr_t paddr;
+-	u32 pool_size;
++	u32 pool_size = 0;
+ 	int idx = ar->wmi.num_mem_chunks;
++	void *vaddr = NULL;
+ 
+-	pool_size = num_units * round_up(unit_len, 4);
++	if (ar->wmi.num_mem_chunks == ARRAY_SIZE(ar->wmi.mem_chunks))
++		return -ENOMEM;
+ 
+-	if (!pool_size)
+-		return -EINVAL;
++	while (!vaddr && num_units) {
++		pool_size = num_units * round_up(unit_len, 4);
++		if (!pool_size)
++			return -EINVAL;
+ 
+-	ar->wmi.mem_chunks[idx].vaddr = dma_alloc_coherent(ar->dev,
+-							   pool_size,
+-							   &paddr,
+-							   GFP_KERNEL);
+-	if (!ar->wmi.mem_chunks[idx].vaddr) {
+-		ath10k_warn(ar, "failed to allocate memory chunk\n");
+-		return -ENOMEM;
++		vaddr = kzalloc(pool_size, GFP_KERNEL | __GFP_NOWARN);
++		if (!vaddr)
++			num_units /= 2;
+ 	}
+ 
+-	memset(ar->wmi.mem_chunks[idx].vaddr, 0, pool_size);
++	if (!num_units)
++		return -ENOMEM;
++
++	paddr = dma_map_single(ar->dev, vaddr, pool_size, DMA_TO_DEVICE);
++	if (dma_mapping_error(ar->dev, paddr)) {
++		kfree(vaddr);
++		return -ENOMEM;
++	}
+ 
++	ar->wmi.mem_chunks[idx].vaddr = vaddr;
+ 	ar->wmi.mem_chunks[idx].paddr = paddr;
+ 	ar->wmi.mem_chunks[idx].len = pool_size;
+ 	ar->wmi.mem_chunks[idx].req_id = req_id;
+ 	ar->wmi.num_mem_chunks++;
+ 
++	return num_units;
++}
++
++static int ath10k_wmi_alloc_host_mem(struct ath10k *ar, u32 req_id,
++				     u32 num_units, u32 unit_len)
++{
++	int ret;
++
++	while (num_units) {
++		ret = ath10k_wmi_alloc_chunk(ar, req_id, num_units, unit_len);
++		if (ret < 0)
++			return ret;
++
++		num_units -= ret;
++	}
++
+ 	return 0;
+ }
+ 
+@@ -7717,10 +7741,11 @@ void ath10k_wmi_free_host_mem(struct ath
+ 
+ 	/* free the host memory chunks requested by firmware */
+ 	for (i = 0; i < ar->wmi.num_mem_chunks; i++) {
+-		dma_free_coherent(ar->dev,
+-				  ar->wmi.mem_chunks[i].len,
+-				  ar->wmi.mem_chunks[i].vaddr,
+-				  ar->wmi.mem_chunks[i].paddr);
++		dma_unmap_single(ar->dev,
++				 ar->wmi.mem_chunks[i].paddr,
++				 ar->wmi.mem_chunks[i].len,
++				 DMA_TO_DEVICE);
++		kfree(ar->wmi.mem_chunks[i].vaddr);
+ 	}
+ 
+ 	ar->wmi.num_mem_chunks = 0;