This is a note to let you know that I've just added the patch titled net: ftgmac100: Fix Aspeed ast2600 TX hang issue to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-ftgmac100-fix-aspeed-ast2600-tx-hang-issue.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Sat Oct 24 11:00:25 AM CEST 2020 From: Dylan Hung <dylan_hung@xxxxxxxxxxxxxx> Date: Wed, 14 Oct 2020 14:06:32 +0800 Subject: net: ftgmac100: Fix Aspeed ast2600 TX hang issue From: Dylan Hung <dylan_hung@xxxxxxxxxxxxxx> [ Upstream commit 137d23cea1c044b2d4853ac71bc68126b25fdbb2 ] The new HW arbitration feature on Aspeed ast2600 will cause MAC TX to hang when handling scatter-gather DMA. Disable the problematic feature by setting MAC register 0x58 bit28 and bit27. Fixes: 39bfab8844a0 ("net: ftgmac100: Add support for DT phy-handle property") Signed-off-by: Dylan Hung <dylan_hung@xxxxxxxxxxxxxx> Reviewed-by: Joel Stanley <joel@xxxxxxxxx> Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/faraday/ftgmac100.c | 5 +++++ drivers/net/ethernet/faraday/ftgmac100.h | 8 ++++++++ 2 files changed, 13 insertions(+) --- a/drivers/net/ethernet/faraday/ftgmac100.c +++ b/drivers/net/ethernet/faraday/ftgmac100.c @@ -1807,6 +1807,11 @@ static int ftgmac100_probe(struct platfo priv->rxdes0_edorr_mask = BIT(30); priv->txdes0_edotr_mask = BIT(30); priv->is_aspeed = true; + /* Disable ast2600 problematic HW arbitration */ + if (of_device_is_compatible(np, "aspeed,ast2600-mac")) { + iowrite32(FTGMAC100_TM_DEFAULT, + priv->base + FTGMAC100_OFFSET_TM); + } } else { priv->rxdes0_edorr_mask = BIT(15); priv->txdes0_edotr_mask = BIT(15); --- a/drivers/net/ethernet/faraday/ftgmac100.h +++ b/drivers/net/ethernet/faraday/ftgmac100.h @@ -170,6 +170,14 @@ #define FTGMAC100_MACCR_SW_RST (1 << 31) /* + * test mode control register + */ +#define FTGMAC100_TM_RQ_TX_VALID_DIS (1 << 28) +#define FTGMAC100_TM_RQ_RR_IDLE_PREV (1 << 27) +#define FTGMAC100_TM_DEFAULT \ + (FTGMAC100_TM_RQ_TX_VALID_DIS | FTGMAC100_TM_RQ_RR_IDLE_PREV) + +/* * PHY control register */ #define FTGMAC100_PHYCR_MDC_CYCTHR_MASK 0x3f Patches currently in stable-queue which might be from dylan_hung@xxxxxxxxxxxxxx are queue-5.4/net-ftgmac100-fix-aspeed-ast2600-tx-hang-issue.patch