View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0001169 | fss5pv210_Linux | Display | public | 2012-07-25 09:32 | 2015-02-04 15:36 |
| Reporter | Keller | Assigned To | |||
| Priority | normal | Severity | minor | Reproducibility | have not tried |
| Status | assigned | Resolution | open | ||
| Product Version | armStoneA8-V1.1 | ||||
| Target Version | fss5pv210-V2.1 | ||||
| Summary | 0001169: LCD resolutions above 1024x768 don't work | ||||
| Description | Setting a display resolution above 1024x768 shows the error: s3c-fb s5pv210-fb: failed to allocate display memory | ||||
| Forum Link | http://forum.fs-net.de/viewtopic.php?f=55&t=3222 | ||||
|
|
The Linux page allocator for DMA capable memory regions has an upper limit of 4MB. If the (virtual) framebuffer uses more than 1 million pixels at 32 bits/pixel, the framebuffer size exceeds this limit and allocation is rejected. Solution 1: Reduce color depth to 16 bits/pixel. Disadvantage: less color shades. Solution 2: Increase limit for page allocator, e.g. to 8MB. Disadvantage: probably unknown side effects. Solution 3: Move the display configuration to U-Boot and reserve a whole memory region for framebuffers. Then the Linux display drivers can avoid calling this restricted page allocator completely. We will implement solution 3, targeted for V2.0. For the implementation of solutions 1 + 2 in the meantime see forum entry http://forum.fs-net.de/viewtopic.php?p=10222#p10222 |
