[Linux-stm32] [PATCH] net: stmmac: reset Tx desc base address before restarting Tx

[David Miller]

From: Jongsung Kim <neidhard.kim at lge.com>
Date: Fri,  6 Dec 2019 20:40:00 +0900

> Refer to the databook of DesignWare Cores Ethernet MAC Universal:
> 
> 6.2.1.5 Register 4 (Transmit Descriptor List Address Register
> 
> If this register is not changed when the ST bit is set to 0, then
> the DMA takes the descriptor address where it was stopped earlier.
> 
> The stmmac_tx_err() does zero indices to Tx descriptors, but does
> not reset HW current Tx descriptor address. To fix inconsistency,
> the base address of the Tx descriptors should be rewritten before
> restarting Tx.
> 
> Signed-off-by: Jongsung Kim <neidhard.kim at lge.com>

Applied.