[PATCH v2] usb: dwc2: add missing SLAB_CACHE_DMA flag for desc_hsisoc_cache

[Karthikeyan K S <karthiproffesional@gmail.com>]

The desc_hsisoc_cache kmem_cache is used to allocate DMA descriptors
for High-Speed isochronous transfers. These descriptors are passed to
the hardware via dma_map_single() in dwc2_desc_list_alloc().

The desc_gen_cache, which serves the same purpose for other transfer
types, correctly specifies SLAB_CACHE_DMA. However, desc_hsisoc_cache
was created without this flag, despite both caches being used
identically for DMA descriptor allocation.

Add the missing SLAB_CACHE_DMA flag to desc_hsisoc_cache for
consistency and correctness on platforms with DMA zone restrictions.
This also protects against future allocations from this cache that
might omit GFP_DMA.

Fixes: 3b5fcc9ac2f4 ("usb: dwc2: host: use kmem cache to allocate descriptors")

Signed-off-by: Karthikeyan K S <karthiproffesional@gmail.com>
---
v2: Resend with proper formatting (previous was corrupted by email client)
---
 drivers/usb/dwc2/hcd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
index 30eb85066..556d6ab36 100644
--- a/drivers/usb/dwc2/hcd.c
+++ b/drivers/usb/dwc2/hcd.c
@@ -5273,7 +5273,7 @@ int dwc2_hcd_init(struct dwc2_hsotg *hsotg)
 
 		hsotg->desc_hsisoc_cache = kmem_cache_create("dwc2-hsisoc-desc",
 				sizeof(struct dwc2_dma_desc) *
-				MAX_DMA_DESC_NUM_HS_ISOC, 512, 0, NULL);
+				MAX_DMA_DESC_NUM_HS_ISOC, 512, SLAB_CACHE_DMA, NULL);
 		if (!hsotg->desc_hsisoc_cache) {
 			dev_err(hsotg->dev,
 				"unable to create dwc2 hs isoc desc cache\n");
-- 
2.43.0