Re: [Linux-fbdev-devel] [RFC PATCH 2/2] ep93xx framebuffer driver

[Ryan M. <ry...@bl...>]

H Hartley Sweeten wrote:
> On Sunday, May 24, 2009 10:34 PM, Ryan Mallon wrote:
>> This patch adds support for the ep93xx framebuffer. Patch is against
>> arm ep93xx branch.
>>
>> Can anybody with ep93xx hardware please test, specifically with regard
>> to the physical address bit 27 bug. My hardware has the bug, but I'm
>> not sure about other ep93xx chips.
> 
> I have not seen the address bit 27 bug on my custom hardware with
> EP9307 Rev E0 silicon.

Have you had the driver allocate a physical memory address which has bit
27 set? I'm basically wondering whether to enable the check by default
or not. If the problem only exists on a few ep93xx chips then it may be
better to leave the check off by default.

>> +
>> +static struct platform_device ep93xx_fb_device = {
>> +	.name			= "ep93xxfb",
>> +	.id			= 0,
> 
> Since there can only be one framebuffer device how about using
> .id = -1?  This will change the clk dev_id to "ep93xxfb".  Also,
> maybe change the name to "ep93xx-fb", that's how the usb host is
> named.

Will fix both.

> 
>> +	.dev.platform_data	= &ep93xxfb_data,
>> +	.dev.coherent_dma_mask	= 0xf7ffffff,
> 
> I think this is supposed to be
> 
> 	.dev.coherent_dma_mask	= DMA_BIT_MASK(32),
> 
> Or is the missing bit due to the address bit 27 bug?

Yeah, its for bit 27. Not sure how to handle this correctly if the check
is a driver option. If you don't have this problem, just change it to
DMA_BIT_MASK(32) for testing.

~Ryan

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