Re: [PATCH 03/10] stmmac: sanitize the rx coe and add the type-1 csum

Hello Deepak,

On 4/2/2012 6:18 PM, Deepak SIKRI wrote:

On 4/2/2012 4:37 PM, Giuseppe CAVALLARO wrote:

[snip]

quoted

I've not clear at all your question.
The driver well uses the rx_coe as briefly described below:

probe funct
   |__ hw_init
          |_ check the RX type from HW cap reg
                  |__ Override the rx_coe if required

After that the rx_coe is used and passed to the core as expected.
In case of there is no HW cap register so the rx_coe from platform will
be used.

Peppe

In the same patch, this portion of the code has been removed.

-static int dwmac1000_rx_coe_supported(void __iomem *ioaddr)
-{
-    u32 value = readl(ioaddr + GMAC_CONTROL);
-
-    value |= GMAC_CONTROL_IPC;
-    writel(value, ioaddr + GMAC_CONTROL);
-
-    value = readl(ioaddr + GMAC_CONTROL);
-
-    return !!(value&  GMAC_CONTROL_IPC);
-}

Earlier this was taking care of setting the IP Checksum offloading feature
in case its available. This code has to be present, as I do not see any
other location where the IPC bit is being programmed.

Also, the location of setting the IPC should be post the mac has been
reset.

Previously, the stmmac called the dwmac1000_rx_coe_supported to verify
it could do the CSUM in Hw. If true the driver used the type 2 by default.

I've voluntarily removed this function because not necessary anymore.
In fact, YOU improved the rx_coe from the platform. If it is passed as
STMMAC_RX_COE_NONE then it means the driver is not able to perform any
csum for the incoming frames. This is actually used on old gmac/mac
cores. In new cores, the HW cap register will be used to manage and fix
this logic.
I could restore the core you are mentioning  but just to do another
safety check at run-time in case of the user provided a broken setting
from the platform and there is not the HW cap register. Hmm, I do not
know if this actually could help indeed... just an extra check IMHO.

I hope this clears the things a bit. Sorry for the miscommunication.

No problem for the miscommunication ;-)

Let me know
Ciao
Peppe

Rgds
Deepak

quoted

quoted

Regards
Deepak

.