Re: [patch 5/7] xenon: add SATA support

Felix Domke wrote:

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Felix Domke wrote:

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This adds support for the HDD and DVD SATA controller on the xenon
southbridge.

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 Pleas post this to linux-ide@vger.kernel.org in the future.

I'll do.

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It also disables ATA_TFLAG_POLLING in libata-core, which prevented the
DVD drive
from being detected. It needs to be investigated what exactly is wrong
here. 

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    tf.protocol = ATA_PROT_PIO;
-    tf.flags |= ATA_TFLAG_POLLING; /* for polling presence detection */
+//    tf.flags |= ATA_TFLAG_POLLING; /* for polling presence
detection */

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  I doubt that this could *ever* get accepted.

It was not meant to be accepted, but to work around the problem which
was introduced in 2.6.19. I have far too less knowledge of the SATA
layer to understand why this flag exactly causes the detection of the
DVD-Drive fail.

As said, this needs to be investigated, and fixed (in the driver, of
course, not in the subsystem).

    Yeah, I've missed it in the patch description. :-<

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+static unsigned int get_scr_cfg_addr(unsigned int port_no, unsigned
int sc_reg, int device)
+{
+    unsigned int addr = SIS_SCR_BASE + (4 * sc_reg);
+

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  Why we need device and port_no arguments here?

As there is only one device/port per PCI device, the arguments should
probably be removed from this function, right.

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+    if (sc_reg == SCR_ERROR) /* doesn't exist in PCI cfg space */
+        return 0; /* assume no error */

  Since SCR_ERROR == 1, this check seems broken.

Why?

    Since get_scr_cfg_addr() will never return 1... oh wait, we're checking 
another variable... :-<
    Maybe worth merging to get_scr_cfg_addr() then, along with (sc_reg > 
SCR_CONTROL) checks, to avoid duplicate code.

Felix

MBR, Sergei