On 02/03/2017 09:54 AM, Hannes Reinecke wrote:
The ioctl SET_FORCE_LOW_DMA has never worked since the initial
git check-in, and the respective setting is nowadays handled
correctly.
So disable it entirely.
Signed-off-by: Hannes Reinecke <h...@suse.com>
---
[...]
case SG_SET_FORCE_LOW_DMA:
- result = get_user(val, ip);
- if (result)
- return result;
- if (val) {
- sfp->low_dma = 1;
- if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
- val = (int) sfp->reserve.bufflen;
- sg_remove_scat(sfp, &sfp->reserve);
- sg_build_reserve(sfp, val);
- }
- } else {
- if (atomic_read(&sdp->detaching))
- return -ENODEV;
- sfp->low_dma = sdp->device->host->unchecked_isa_dma;
- }
- return 0;
+ return -EINVAL;
I'm not sure if returning a bogus '0' is better here to not break any
existing application, which assumed it always worked.
