RE: [Intel-wired-lan] [PATCH] ixgbevf: Remove useless DMA-32 fallback configuration

From: G, GurucharanX
Date: Thu Jan 13 2022 - 12:48:53 EST




> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@xxxxxxxxxx> On Behalf Of
> Christophe JAILLET
> Sent: Sunday, January 9, 2022 10:52 PM
> To: Brandeburg, Jesse <jesse.brandeburg@xxxxxxxxx>; Nguyen, Anthony L
> <anthony.l.nguyen@xxxxxxxxx>; David S. Miller <davem@xxxxxxxxxxxxx>;
> Jakub Kicinski <kuba@xxxxxxxxxx>
> Cc: netdev@xxxxxxxxxxxxxxx; kernel-janitors@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; Christophe JAILLET
> <christophe.jaillet@xxxxxxxxxx>; intel-wired-lan@xxxxxxxxxxxxxxxx; Christoph
> Hellwig <hch@xxxxxx>
> Subject: [Intel-wired-lan] [PATCH] ixgbevf: Remove useless DMA-32 fallback
> configuration
>
> As stated in [1], dma_set_mask() with a 64-bit mask never fails if
> dev->dma_mask is non-NULL.
> So, if it fails, the 32 bits case will also fail for the same reason.
>
> So, if dma_set_mask_and_coherent() succeeds, 'pci_using_dac' is known to
> be 1.
>
> Simplify code and remove some dead code accordingly.
>
> [1]: https://lkml.org/lkml/2021/6/7/398
>
> Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> Reviewed-by: Christoph Hellwig <hch@xxxxxx>
> Reviewed-by: Alexander Lobakin <alexandr.lobakin@xxxxxxxxx>
> ---
> .../net/ethernet/intel/ixgbevf/ixgbevf_main.c | 20 ++++++-------------
> 1 file changed, 6 insertions(+), 14 deletions(-)
>

Tested-by: Gurucharan G <gurucharanx.g@xxxxxxxxx> (A Contingent worker at Intel)