On Sun, 2021-10-17 at 13:07 +0200, Dorota Czaplejewicz wrote: > Hello, > > On Thu, 14 Oct 2021 13:26:26 +0200 > Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> wrote: > > > Hi Dorota, > > > > On Wed, 2021-10-13 at 11:26 +0200, Dorota Czaplejewicz wrote: > > > On Fri, 08 Oct 2021 14:19:41 +0200 Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> wrote: > > [...] > > > > I wonder: if you use 4-byte aligned width and odd height, does the CSI > > > > write over the end of the buffer? > > > > > > I tested this case, and found a glitch which suggests the last 4 bytes are ignored: > > > > > > https://source.puri.sm/Librem5/linux-next/uploads/cfb59e3832431aaa3a69549455502568/image.png > > > > Thank you for testing, so it appears that at least without FBUF_STRIDE > > the only requirement is that the whole image size must be a multiple of > > 8 bytes. > > > > > That would be taken care of rounding up towards a number decided at runtime, like: > > > > > > divisor = 8 >> (mbus->height % 2); > > > > Which would then cause the CSI to write past the end of the buffer? > > > I'm not sure if you point out the mistake here (should be "4 <<"), or > the fact that rounding is happening. If it's the latter, then it's of > no concern: the values derived here are used to calculate buffer size. > > I'm submitting a new series where this is fixed. Thanks, I just didn't understand your intention. The name "divisor" threw me off, see the comment in the new series. regards Philipp
