From: Nuno Sa <nuno.sa@xxxxxxxxxx> Aligning to the L1 cache does guarantee the same alignment as kmallocing an object [1]. Furthermore, in some platforms, that alignment is not sufficient for DMA safety (in case someone wants to have a DMA safe buffer in privdata) [2]. Sometime ago, we had the same fixes in IIO. [1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/base/devres.c#n35 [2]: https://lore.kernel.org/linux-iio/20220508175712.647246-2-jic23@xxxxxxxxxx/ Fixes: c18e2760308e ("counter: Provide alternative counter registration functions") Signed-off-by: Nuno Sa <nuno.sa@xxxxxxxxxx> --- William, if you prefer, we can do something like in IIO and add a specific COUNTER_DMA_MINALIGN define --- drivers/counter/counter-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/counter/counter-core.c b/drivers/counter/counter-core.c index 09c77afb33ca..073bf6b67a57 100644 --- a/drivers/counter/counter-core.c +++ b/drivers/counter/counter-core.c @@ -34,7 +34,7 @@ struct counter_device_allochelper { * This is cache line aligned to ensure private data behaves like if it * were kmalloced separately. */ - unsigned long privdata[] ____cacheline_aligned; + unsigned long privdata[] __aligned(ARCH_DMA_MINALIGN); }; static void counter_device_release(struct device *dev) --- base-commit: 6613476e225e090cc9aad49be7fa504e290dd33d change-id: 20240205-counter-align-fix-3faebfb572af -- Thanks! - Nuno Sá
