The driver currently only waits for DMA_MODE SWR bit to clear itself. This is insufficient e.g. on i.MX8M Plus, where the MAC must be reset before IOMUX GPR[1] content is latched into the MAC and used. Without the proper reset, the i.MX8M Plus MAC variant does not take the value in IOMUX GPR[1] into account, which makes it impossible e.g. to switch interface mode from RGMII to any other.
Since proper reset is desired in general to put the block into defined state, always assert the DMA_MODE SWR bit before waiting for the bit to clear itself.
Reviewed-by: Ramon Fried rfried.dev@gmail.com Signed-off-by: Marek Vasut marex@denx.de --- Cc: "Ariel D'Alessandro" ariel.dalessandro@collabora.com Cc: "NXP i.MX U-Boot Team" uboot-imx@nxp.com Cc: Andrey Zhizhikin andrey.zhizhikin@leica-geosystems.com Cc: Fabio Estevam festevam@gmail.com Cc: Joe Hershberger joe.hershberger@ni.com Cc: Lukasz Majewski lukma@denx.de Cc: Marcel Ziswiler marcel.ziswiler@toradex.com Cc: Marek Vasut marex@denx.de Cc: Michael Trimarchi michael@amarulasolutions.com Cc: Peng Fan peng.fan@nxp.com Cc: Ramon Fried rfried.dev@gmail.com Cc: Sean Anderson seanga2@gmail.com Cc: Stefano Babic sbabic@denx.de Cc: Tim Harvey tharvey@gateworks.com Cc: Tommaso Merciai tommaso.merciai@amarulasolutions.com Cc: u-boot@lists.denx.de --- V2: Add RB from Ramon --- drivers/net/dwc_eth_qos.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/drivers/net/dwc_eth_qos.c b/drivers/net/dwc_eth_qos.c index bdf0f2e6812..66e3f354b65 100644 --- a/drivers/net/dwc_eth_qos.c +++ b/drivers/net/dwc_eth_qos.c @@ -761,6 +761,12 @@ static int eqos_start(struct udevice *dev)
eqos->reg_access_ok = true;
+ /* + * Assert the SWR first, the actually reset the MAC and to latch in + * e.g. i.MX8M Plus GPR[1] content, which selects interface mode. + */ + setbits_le32(&eqos->dma_regs->mode, EQOS_DMA_MODE_SWR); + ret = wait_for_bit_le32(&eqos->dma_regs->mode, EQOS_DMA_MODE_SWR, false, eqos->config->swr_wait, false);