Re: [PATCH 2.6.19-rc1 update4] drivers: add LCD support

From: Andrew Morton
Date: Fri Oct 27 2006 - 01:07:37 EST


On Thu, 26 Oct 2006 17:48:58 +0000
Miguel Ojeda Sandonis <maxextreme@xxxxxxxxx> wrote:

>
> +DECLARE_MUTEX(cfag12864bfb_sem);

Mutexes are preferred - please only use semaphores if their counting
feature is required.

This lock can have static scope.

> +struct page *cfag12864bfb_vma_nopage(struct vm_area_struct *vma,
> + unsigned long address, int *type)

This function can have static scope.

> +{
> + struct page *page;
> + down(&cfag12864bfb_sem);
> +
> + page = virt_to_page(cfag12864b_buffer);
> + get_page(page);
> +
> + if(type)
> + *type = VM_FAULT_MINOR;
> +
> + up(&cfag12864bfb_sem);
> + return page;
> +}

What's the semaphore actually needed for?

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