[U-Boot] [PATCH 2/4] net: fec: do not access reserved register for i.MX6UL

Peng Fan
2015-08-06T04:41:29Z

Hi Nikolay,
On Wed, Aug 05, 2015 at 05:31:27PM +0300, Nikolay Dimitrov wrote:
>Hi Peng,
>
>On 08/03/2015 01:06 PM, Peng Fan wrote:
>>The MIB RAM and FIFO receive start register does not exist on
>>i.MX6UL. Accessing these register will cause enet not work well.
>>
>>Signed-off-by: Peng Fan <Peng.Fan@freescale.com>
>>Signed-off-by: Fugang Duan <B38611@freescale.com>
>>Cc: Joe Hershberger <joe.hershberger@ni.com>
>>---
>> drivers/net/fec_mxc.c | 4 ++++
>> 1 file changed, 4 insertions(+)
>>
>>diff --git a/drivers/net/fec_mxc.c b/drivers/net/fec_mxc.c
>>index c5dcbbb..7fb1d5f 100644
>>--- a/drivers/net/fec_mxc.c
>>+++ b/drivers/net/fec_mxc.c
>>@@ -520,8 +520,10 @@ static int fec_open(struct eth_device *edev)
>> static int fec_init(struct eth_device *dev, bd_t* bd)
>> {
>> struct fec_priv *fec = (struct fec_priv *)dev->priv;
>>+#if !defined(CONFIG_MX6UL)
>> uint32_t mib_ptr = (uint32_t)&fec->eth->rmon_t_drop;
>> int i;
>>+#endif
>>
>> /* Initialize MAC address */
>> fec_set_hwaddr(dev);
>>@@ -551,12 +553,14 @@ static int fec_init(struct eth_device *dev, bd_t* bd)
>> writel(0x00000000, &fec->eth->gaddr2);
>>
>>
>>+#if !defined(CONFIG_MX6UL)
>> /* clear MIB RAM */
>> for (i = mib_ptr; i <= mib_ptr + 0xfc; i += 4)
>> writel(0, i);
>>
>> /* FIFO receive start register */
>> writel(0x520, &fec->eth->r_fstart);
>>+#endif
>>
>> /* size and address of each buffer */
>> writel(FEC_MAX_PKT_SIZE, &fec->eth->emrbr);
>>
>
>Is it possible to do runtime check for the SoC type, instead of ifdefs?

This driver is used by i.MX7 and i.MX6, but i.MX7 patchset has not been
upstreamed now.

I considered using "if (!is_cpu_type(MXC_CPU_MX6UL))", but this will cause
i.MX7 fail to complile successfully, because i.MX7 does not support the macro
MXC_CPU_MX6UL.

The way I can think out is to refactor the code to support DM or FDT,
using compatible string to figure out which SoC. But now I do not have
much time to refactor the driver. So I just use the "#if !defined" way
which is not good solution.

Regards,
Peng.
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