sfc: simplify DMA mask setting (08bdbcae) · Commits · 戴 / test

Christoph says[1] that dma_set_mask_and_coherent() is smart enough to truncate the mask itself if it's too long. So we can get rid of our "lop off one bit and retry" loop in efx_init_io(). [1]: https://www.spinics.net/lists/netdev/msg677266.html Signed-off-by:

Edward Cree <ecree@solarflare.com> Signed-off-by:

Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/sfc/efx_common.c

+1 −11

Original line number	Diff line number	Diff line
		@@ -1086,17 +1086,7 @@ int efx_init_io(struct efx_nic *efx, int bar, dma_addr_t dma_mask,

		pci_set_master(pci_dev);

		/* Set the PCI DMA mask. Try all possibilities from our
		* genuine mask down to 32 bits, because some architectures
		* (e.g. x86_64 with iommu_sac_force set) will allow 40 bit
		* masks event though they reject 46 bit masks.
		*/
		while (dma_mask > 0x7fffffffUL) {
		rc = dma_set_mask_and_coherent(&pci_dev->dev, dma_mask);
		if (rc == 0)
		break;
		dma_mask >>= 1;
		}
		if (rc) {
		netif_err(efx, probe, efx->net_dev,
		"could not find a suitable DMA mask\n");

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