Benjamin Herrenschmidt wrote:
> On Thu, 2008-02-21 at 17:46 +0300, Valentine Barshak wrote:
>> The PowerPC 440GX Taishan board fails to reset EMAC3 (reset timeout error)
>> and because of that it can't find PHY chip. The older ibm_emac driver had
>> a workaround for that: the EMAC_CLK_INTERNAL/EMAC_CLK_EXTERNAL macros which
>> toggle the Ethernet Clock Select bit in the SDR0_MFR register. This patch
>> does the same for "ibm,emac-440gx" compatible chips.
>
> The main problem is that will force clock on -all- EMACs ... which can
> be a problem as they can be in probe at the same time. Might be worth
> also adding a global mutex around that block.
I've tried to move clock selection inside the global emac_phy_map_lock
block. That works fine for 440GX.
>
> Also, would you mind having a look at the other workaround for the
> similar bug?
OK, I'll add 440EP/440GR workaround, but I'm not sure if we need it for
the currently supported boards. The older ibm_emac driver also has a
workaround for it on 405ep. This part uses CPC0 dcr registers. So, looks
like we'll have to search device tree for the CPC0 entry in ibm_newemac
driver, map dcr registers and select clock with dcr_read/write calls.
I've omitted the 405ep part, since there's currently no board supported.
Thanks,
Valentine.
>
> Cheers,
> Ben.
>
>> Signed-off-by: Valentine Barshak <[EMAIL PROTECTED]>
>> ---
>> drivers/net/ibm_newemac/core.c | 16 +++++++++++++++-
>> drivers/net/ibm_newemac/core.h | 8 ++++++--
>> 2 files changed, 21 insertions(+), 3 deletions(-)
>>
>> diff -pruN linux-2.6.orig/drivers/net/ibm_newemac/core.c
>> linux-2.6/drivers/net/ibm_newemac/core.c
>> --- linux-2.6.orig/drivers/net/ibm_newemac/core.c 2008-02-21
>> 16:45:36.000000000 +0300
>> +++ linux-2.6/drivers/net/ibm_newemac/core.c 2008-02-21 17:21:21.000000000
>> +0300
>> @@ -43,6 +43,8 @@
>> #include <asm/io.h>
>> #include <asm/dma.h>
>> #include <asm/uaccess.h>
>> +#include <asm/dcr.h>
>> +#include <asm/dcr-regs.h>
>>
>> #include "core.h"
>>
>> @@ -2480,8 +2482,11 @@ static int __devinit emac_init_config(st
>> }
>>
>> /* Check EMAC version */
>> - if (of_device_is_compatible(np, "ibm,emac4"))
>> + if (of_device_is_compatible(np, "ibm,emac4")) {
>> dev->features |= EMAC_FTR_EMAC4;
>> + if (of_device_is_compatible(np, "ibm,emac-440gx"))
>> + dev->features |= EMAC_FTR_440GX_PHY_CLK_FIX;
>> + }
>>
>> /* Fixup some feature bits based on the device tree */
>> if (of_get_property(np, "has-inverted-stacr-oc", NULL))
>> @@ -2673,8 +2678,17 @@ static int __devinit emac_probe(struct o
>> dev->stop_timeout = STOP_TIMEOUT_100;
>> INIT_DELAYED_WORK(&dev->link_work, emac_link_timer);
>>
>> + /* Enable internal phy clock source */
>> + if (emac_has_feature(dev, EMAC_FTR_440GX_PHY_CLK_FIX))
>> + mtdcri(SDR0, SDR0_MFR, mfdcri(SDR0, SDR0_MFR) | SDR0_MFR_ECS);
>> +
>> /* Find PHY if any */
>> err = emac_init_phy(dev);
>> +
>> + /* Enable external phy clock source */
>> + if (emac_has_feature(dev, EMAC_FTR_440GX_PHY_CLK_FIX))
>> + mtdcri(SDR0, SDR0_MFR, mfdcri(SDR0, SDR0_MFR) & ~SDR0_MFR_ECS);
>> +
>> if (err != 0)
>> goto err_detach_tah;
>>
>> diff -pruN linux-2.6.orig/drivers/net/ibm_newemac/core.h
>> linux-2.6/drivers/net/ibm_newemac/core.h
>> --- linux-2.6.orig/drivers/net/ibm_newemac/core.h 2008-02-21
>> 16:45:36.000000000 +0300
>> +++ linux-2.6/drivers/net/ibm_newemac/core.h 2008-02-21 17:21:47.000000000
>> +0300
>> @@ -301,6 +301,10 @@ struct emac_instance {
>> * Set if we have new type STACR with STAOPC
>> */
>> #define EMAC_FTR_HAS_NEW_STACR 0x00000040
>> +/*
>> + * Set if we need phy clock workaround for 440gx
>> + */
>> +#define EMAC_FTR_440GX_PHY_CLK_FIX 0x00000080
>>
>>
>> /* Right now, we don't quite handle the always/possible masks on the
>> @@ -312,8 +316,8 @@ enum {
>>
>> EMAC_FTRS_POSSIBLE =
>> #ifdef CONFIG_IBM_NEW_EMAC_EMAC4
>> - EMAC_FTR_EMAC4 | EMAC_FTR_HAS_NEW_STACR |
>> - EMAC_FTR_STACR_OC_INVERT |
>> + EMAC_FTR_EMAC4 | EMAC_FTR_HAS_NEW_STACR |
>> + EMAC_FTR_STACR_OC_INVERT | EMAC_FTR_440GX_PHY_CLK_FIX |
>> #endif
>> #ifdef CONFIG_IBM_NEW_EMAC_TAH
>> EMAC_FTR_HAS_TAH |
>
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