On 05/10/2026 21:11, Ruinskiy, Dima wrote:
On 13/09/2026 20:15, Matt Vollrath wrote:
Upon encountering a DMA_MAPPING_ERROR during skb allocation and mapping,
the driver would leave DMA_MAPPING_ERROR in the buffer_info->dma field.
This would lead several buffer_info->dma == 0 conditions down unwanted
paths:
* In e1000_alloc_jumbo_rx_buffers(), it would not re-attempt the failed
mapping and instead write DMA_MAPPING_ERROR to the h/w descriptor on
the next allocation call. On cleaning or teardown it would attempt to
dma_unmap_page() DMA_MAPPING_ERROR. This case would only be
reachable at MTU > 1518 and page size > 16K.
* In e1000_clean_rx_ring(), it would attempt to dma_unmap_page/single()
DMA_MAPPING_ERROR (unless cleaned by the jumbo path first). This case
would be reachable at any combination of MTU and page size.
Use buffer_info->dma = 0 as the sentinel for "DMA is not mapped." Set it
immediately upon detecting the failure.
The map error value was 0 on some platforms (including most common x86)
until error values were unified to DMA_MAPPING_ERROR in v4.20/v5.0.
Since then the error handling in this driver has been incorrect on all
platforms.
Signed-off-by: Matt Vollrath <[email protected]>
Suggested-by: Jakub Kicinski <[email protected]>
Fixes: bc7f75fa9788 ("[E1000E]: New pci-express e1000 driver
(currently for ICH9 devices only)")
Cc: [email protected]
---
v2:
* Add history blurb to description.
---
drivers/net/ethernet/intel/e1000e/netdev.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/
ethernet/intel/e1000e/netdev.c
index 844f31ab37ad..26f45ee8c7e7 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -691,6 +691,7 @@ static void e1000_alloc_rx_buffers(struct
e1000_ring *rx_ring,
adapter->rx_buffer_len,
DMA_FROM_DEVICE);
if (dma_mapping_error(&pdev->dev, buffer_info->dma)) {
+ buffer_info->dma = 0;
dev_err(&pdev->dev, "Rx DMA map failed\n");
adapter->rx_dma_failed++;
break;
@@ -791,6 +792,7 @@ static void e1000_alloc_rx_buffers_ps(struct
e1000_ring *rx_ring,
adapter->rx_ps_bsize0,
DMA_FROM_DEVICE);
if (dma_mapping_error(&pdev->dev, buffer_info->dma)) {
+ buffer_info->dma = 0;
dev_err(&pdev->dev, "Rx DMA map failed\n");
adapter->rx_dma_failed++;
/* cleanup skb */
@@ -877,6 +879,7 @@ static void e1000_alloc_jumbo_rx_buffers(struct
e1000_ring *rx_ring,
PAGE_SIZE,
DMA_FROM_DEVICE);
if (dma_mapping_error(&pdev->dev, buffer_info->dma)) {
+ buffer_info->dma = 0;
adapter->alloc_rx_buff_failed++;
break;
}
base-commit: 78445023439506ebd83b86d40b1e428a3b309d4a
Reviewed-by: Dima Ruinskiy <[email protected]>
Tested-by: Moriya Kadosh <[email protected]>
