Completion flag rarely NOT assert when i.MX53 FEC MII recieve completed

torus1000 — Fri, 29 May 2015 02:48:11 GMT

Dear Expert-team,

FEC_EIR[23](MII interrupt) rarely NOT assert when i.MX53 FEC MII data recieve (or read reg of PHY) completed.
If this happend, communication force disconnected. It was clearly not satisfied our product requirements.

Why didn't FEC_EIR[23] flag changed?

Is there any workaround for this?

Thanks.

Re: Completion flag rarely NOT assert when i.MX53 FEC MII recieve completed

igorpadykov — Thu, 04 Jun 2015 01:04:40 GMT

Hi torus1000

one can try to check if this is caused by FEC FIFO overrun issue,

that is FEC DMA cannot access ddr in time:

1, Prioritize the master via M4IF.

Increase FEC priority:

0x63fd_8044=0x33

0x63fd_8048=0x1901a3

2, Increase FEC RX FIFO size.

RX FIFO size = 1.5*(orginal size) => 0x63fe_c150=0x480

RX FIFO size = 1.625*(orginal size) => 0x63fe_c150=0x460

The result as below table, and the patch as below.

Kernel Patch:

--- a/drivers/net/fec.c

+++ b/drivers/net/fec.c

@@ -1300,6 +1300,11 @@ fec_restart(struct net_device *dev, int duplex)

writel(0, fep->hwp + FEC_HASH_TABLE_LOW);

#endif

+ /* Set RX FIFO */

+#ifdef CONFIG_ARCH_MX53

+ writel(0x480, fep->hwp + FEC_R_FSTART);

+#endif

/* Set maximum receive buffer size. */

writel(PKT_MAXBLR_SIZE, fep->hwp + FEC_R_BUFF_SIZE);

Uboot patch:

--- a/board/freescale/mx53_smd/lowlevel_init.S

+++ b/board/freescale/mx53_smd/lowlevel_init.S

@@ -81,6 +81,17 @@

beq 1b

.endm

+/* M4IF setup */

+.macro init_m4if

+ ldr r0, =M4IF_BASE_ADDR

+ ldr r1, =0x33

+ str r1, [r0, #0x44]

+ ldr r1, =0x001901A3

+ str r1, [r0, #0x48]

+.endm /* init_m4if */

.macro init_clock

ldr r0, =ROM_SI_REV

ldr r1, [r0]

@@ -218,6 +229,8 @@ lowlevel_init:

init_l2cc

init_aips

+ init_m4if

init_clock

Best regards

igor

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topic Re: Completion flag rarely NOT assert when i.MX53 FEC MII recieve completed in i.MX Processors

Completion flag rarely NOT assert when i.MX53 FEC MII recieve completed

Re: Completion flag rarely NOT assert when i.MX53 FEC MII recieve completed