6.6-stable review patch. If anyone has any objections, please let me know.
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From: Pavan Chebbi pavan.chebbi@broadcom.com
[ Upstream commit 614f4d166eeeb9bd709b0ad29552f691c0f45776 ]
The hardware on Broadcom 1G chipsets have a known limitation where they cannot handle DMA addresses that cross over 4GB. When such an address is encountered, the hardware sets the address overflow error bit in the DMA status register and triggers a reset.
However, BCM57766 hardware is setting the overflow bit and triggering a reset in some cases when there is no actual underlying address overflow. The hardware team analyzed the issue and concluded that it is happening when the status block update has an address with higher (b16 to b31) bits as 0xffff following a previous update that had lowest bits as 0xffff.
To work around this bug in the BCM57766 hardware, set the coherent dma mask from the current 64b to 31b. This will ensure that upper bits of the status block DMA address are always at most 0x7fff, thus avoiding the improper overflow check described above. This work around is intended for only status block and ring memories and has no effect on TX and RX buffers as they do not require coherent memory.
Fixes: 72f2afb8a685 ("[TG3]: Add DMA address workaround") Reported-by: Salam Noureddine noureddine@arista.com Reviewed-by: Kalesh AP kalesh-anakkur.purayil@broadcom.com Reviewed-by: Somnath Kotur somnath.kotur@broadcom.com Signed-off-by: Pavan Chebbi pavan.chebbi@broadcom.com Reviewed-by: Michal Kubiak michal.kubiak@intel.com Link: https://patch.msgid.link/20241119055741.147144-1-pavan.chebbi@broadcom.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/broadcom/tg3.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c index f1c8ff5b63acd..7f74e5e106d9d 100644 --- a/drivers/net/ethernet/broadcom/tg3.c +++ b/drivers/net/ethernet/broadcom/tg3.c @@ -17731,6 +17731,9 @@ static int tg3_init_one(struct pci_dev *pdev, } else persist_dma_mask = dma_mask = DMA_BIT_MASK(64);
+ if (tg3_asic_rev(tp) == ASIC_REV_57766) + persist_dma_mask = DMA_BIT_MASK(31); + /* Configure DMA attributes. */ if (dma_mask > DMA_BIT_MASK(32)) { err = dma_set_mask(&pdev->dev, dma_mask);