Re: cache problem

[Ken T. <ke...@we...>]

On Wed, 26 Sep 2001, Rene Brothuhn wrote:

Hello,

What kernel version are you running ?

Something odd in 2.4.8 caused the 53c7xx.c A4091 driver to hang my system
at boot time but only with a modular kernel, even though 53c7xx.c is not a
module.  Monolithic kernels were OK.

And it was hanging somewhere around :

    memset((void *)instance->hostdata[0], 0, 8192);
    cache_push(virt_to_phys((void *)(instance->hostdata[0])), 8192);
    cache_clear(virt_to_phys((void *)(instance->hostdata[0])), 8192);
    kernel_set_cachemode(instance->hostdata[0], 8192, IOMAP_NOCACHE_SER);

similar to what you have.

The current 2.4.9 CVS is OK.

(There are problems with the A4091 driver but that's a ZORRO bus glitch)

> Then the driver starts a test where the 53c770 is exchanging some 53c770 
> register values with some values in np.
> The test fails, because np is cached!
> If I explicitly call: flush_dcache_range(np, np + sizeof(np)); before 
> and after this test, the test doesn`t fail.

Have a look at the tests in 53c7xx.c, they work. I noticed the use of
barrier() in one test.

Ken.