display: ensure samples check display api func return value + ltdc read/write rectangle check #99166
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Ensure that display api function return values are checked. Signed-off-by: Alain Volmat <[email protected]>
Ensure that x,y/width-height rectangle mentioned in display_read and display_write are actually part of the framebuffer, otherwise return an error. Signed-off-by: Alain Volmat <[email protected]>
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area: Samples
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uLipe
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| ret = display_blanking_off(display_dev); | ||
| if (ret < 0 && ret != -ENOSYS) { | ||
| LOG_ERR("Failed to turn blanking off (error %d)", ret); | ||
| return 0; |
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Actually I have been wondering about what to return and couldn't really find a common behavior between samples. For example few lines above, if the device is not ready, gives an error message but also return 0.
In some other sample, a non 0 value is returned but most common behavior seems to return 0.
In this PR I tried as much as possible to stick to what is done within each sample even if I feel it weird to return 0 on error. I would be ok to return ret in case of error in fact but, this has to be done commonly I think with other samples.
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Samples should return 0.
| ret = display_blanking_off(display_dev); | ||
| if (ret < 0 && ret != -ENOSYS) { | ||
| LOG_ERR("Failed to turn blanking off (error %d)", ret); | ||
| return ret; |
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| return ret; | |
| return 0; |
5 participants
Following PR #98719, add proper display API function return value checks in all samples in order to fail if an error happen.
Moreover, within the LTDC driver, ensure that the rectangle given (x,y / width-height) properly fit into the framebuffer in order xto avoid OOB access.
Such check is currently done within the LTDC only, however I think that some of those checks should be done within the API functions themself to ensure a first level of proper parameter validity. In order to have proper behavior of all display drivers, some level of framework level checks can be done, removing amount of duplicated code between drivers.
I will prepare a PR for that purpose and propose it.