Merge tag 'spi-nor/for-5.19' into mtd/next

SPI NOR core changes:
- Read back written SR value to make sure the write was done correctly.
- Introduce a common function for Read ID that manufacturer drivers can
  use to verify the Octal DTR switch worked correctly.
- Add helpers for read/write any register commands so manufacturer
  drivers don't open code it every time.
- Clarify rdsr dummy cycles documentation.
- Add debugfs entry to expose internal flash parameters and state.

SPI NOR manufacturer drivers changes:
- Add support for Winbond W25Q512NW-IM, and Eon EN25QH256A.
- Move spi_nor_write_ear() to Winbond module since only Winbond flashes
  use it.
- Rework Micron and Cypress Octal DTR enable methods to improve
  readability.
- Use the common Read ID function to verify switch to Octal DTR mode for
  Micron and Cypress flashes.
- Skip polling status on volatile register writes for Micron and Cypress
  flashes since the operation is instant.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

1 files changed, 11 insertions, 4 deletions

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 10bde7c6db44..30b523fa4ad2 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -5276,11 +5276,18 @@ bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from,
 	if (skb_cloned(to))
 		return false;
 
-	/* The page pool signature of struct page will eventually figure out
-	 * which pages can be recycled or not but for now let's prohibit slab
-	 * allocated and page_pool allocated SKBs from being coalesced.
+	/* In general, avoid mixing slab allocated and page_pool allocated
+	 * pages within the same SKB. However when @to is not pp_recycle and
+	 * @from is cloned, we can transition frag pages from page_pool to
+	 * reference counted.
+	 *
+	 * On the other hand, don't allow coalescing two pp_recycle SKBs if
+	 * @from is cloned, in case the SKB is using page_pool fragment
+	 * references (PP_FLAG_PAGE_FRAG). Since we only take full page
+	 * references for cloned SKBs at the moment that would result in
+	 * inconsistent reference counts.
 	 */
-	if (to->pp_recycle != from->pp_recycle)
+	if (to->pp_recycle != (from->pp_recycle && !skb_cloned(from)))
 		return false;
 
 	if (len <= skb_tailroom(to)) {