Re: [PATCH v2] media: stm32: dcmi: Switch to __v4l2_subdev_state_alloc()
From: Marek Vasut <marex@denx.de>
Date: 2022-06-30 00:31:57
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linux-media
On 6/29/22 15:19, Tomi Valkeinen wrote:
On 29/06/2022 15:39, Marek Vasut wrote:quoted
On 6/29/22 14:26, Tomi Valkeinen wrote: [...]quoted
quoted
quoted
Perhaps the best way to solve this is just to remove the underscores from __v4l2_subdev_state_alloc, and change all the drivers which create temporary v4l2_subdev_states to use that (and the free) functions. And also create the helper macro which can be used in those cases where the call is simple (the state is not modified or accessed by the caller).As long as we prevent any new driver from using that API, that's fine with me.An alternative would be to keep the v4l2_subdev_state as a local variable (allocated in the stack), and add a new function, v4l2_subdev_state_local_init() or such. The function would initialize the given state, expecting the allocatable fields to be already allocated (state->pads, which in the above cases points to another local variable, i.e. stack). This would prevent the need of a free call, which, while not complex as such, might cause a bigger amount of changes in some cases to handle the error paths correctly. Of course, if the above-mentioned macro works, then that's the easiest solution. But that won't work for all drivers.Don't you think a driver fix shouldn't involve "rework the subsystem" requirement to be applicable ?No, but we should think what's the best way to do the fix, if the fix is controversial. Otherwise we might just break things even worse. Adding the macro seems like a much better way, and far from "rework the subsystem". Granted, this was just a quick edit without testing so it may fail miserably... Can you try this out?
It seems to work as well. How shall we proceed ? _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel