From mboxrd@z Thu Jan 1 00:00:00 1970 From: Albert ARIBAUD Date: Sun, 3 Feb 2013 12:19:26 +0100 Subject: [U-Boot] [Drivers PATCH 14/19] net/macb: workaround for transmission hang issue In-Reply-To: References: <1c8cd3ce05a1064788a96bb4b49f9b82d9caf736.1351877124.git.vipin.kumar@st.com> Message-ID: <20130203121926.78fb7cda@lilith> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi Vipin, On Fri, 2 Nov 2012 23:09:59 +0530, Vipin Kumar wrote: > From: Shiraz Hashim > > It is observed on SPEAr320S RMII#1 interface that on transmitting > packets the MAC dma hangs randomly and constantly showing busy tx-go > state. > > It comes out if this situation only when Transmission is disabled and > enabled again. > > Since it happens randomly and u-boot doesn't require high performance we > disable TE and re-enable it on each transmission. We also change number > of transmit descriptor to 1 as we would not require more than it, further > it would not alter GMAC notion of transmit descriptor start queue as it > always point to same descriptor. > > Signed-off-by: Shiraz Hashim > --- > drivers/net/macb.c | 38 ++++++++++++++++++++++++++++++++++---- > 1 file changed, 34 insertions(+), 4 deletions(-) > > diff --git a/drivers/net/macb.c b/drivers/net/macb.c > index ac25b52..17bad33 100644 > --- a/drivers/net/macb.c > +++ b/drivers/net/macb.c > @@ -55,7 +55,7 @@ > > #define CONFIG_SYS_MACB_RX_BUFFER_SIZE 4096 > #define CONFIG_SYS_MACB_RX_RING_SIZE (CONFIG_SYS_MACB_RX_BUFFER_SIZE / 128) > -#define CONFIG_SYS_MACB_TX_RING_SIZE 16 > +#define CONFIG_SYS_MACB_TX_RING_SIZE 1 > #define CONFIG_SYS_MACB_TX_TIMEOUT 1000 > #define CONFIG_SYS_MACB_AUTONEG_TIMEOUT 5000000 > > @@ -226,7 +226,13 @@ static int macb_send(struct eth_device *netdev, void *packet, int length) > macb->tx_ring[tx_head].ctrl = ctrl; > macb->tx_ring[tx_head].addr = paddr; > barrier(); > - macb_writel(macb, NCR, MACB_BIT(TE) | MACB_BIT(RE) | MACB_BIT(TSTART)); > + /* > + * Due to issues on SPEAr320 RMII, disable TE first so that > + * controller can come out if it is hanged during transmission > + */ > + macb_writel(macb, NCR, macb_readl(macb, NCR) & ~MACB_BIT(TE)); > + macb_writel(macb, NCR, macb_readl(macb, NCR) | > + MACB_BIT(TE) | MACB_BIT(TSTART)); > > /* > * I guess this is necessary because the networking core may > @@ -444,6 +450,31 @@ static int macb_phy_init(struct macb_device *macb) > } > } > > +static void macb_reset_hw(struct macb_device *bp) > +{ > + /* Make sure we have the write buffer for ourselves */ > + barrier(); > + /* > + * Disable RX and TX (XXX: Should we halt the transmission > + * more gracefully?) and we should not close the mdio port > + */ > + macb_writel(bp, NCR, 0); > + > + /* Clear the stats registers (XXX: Update stats first?) */ > + macb_writel(bp, NCR, MACB_BIT(CLRSTAT)); > + > + /* keep the mdio port , otherwise other eth will not work */ > + macb_writel(bp, NCR, MACB_BIT(MPE)); > + > + /* Clear all status flags */ > + macb_writel(bp, TSR, ~0UL); > + macb_writel(bp, RSR, ~0UL); > + > + /* Disable all interrupts */ > + macb_writel(bp, IDR, ~0UL); > + macb_readl(bp, ISR); > +} > + > static int macb_init(struct eth_device *netdev, bd_t *bd) > { > struct macb_device *macb = to_macb(netdev); > @@ -520,8 +551,7 @@ static void macb_halt(struct eth_device *netdev) > tsr = macb_readl(macb, TSR); > } while (tsr & MACB_BIT(TGO)); > > - /* Disable TX and RX, and clear statistics */ > - macb_writel(macb, NCR, MACB_BIT(CLRSTAT)); > + macb_reset_hw(macb); > } > > static int macb_write_hwaddr(struct eth_device *dev) This patch did not reappear in later versions of the series, and no other standalone patch seems to match it. Was it dropped? Amicalement, -- Albert.