netdev - [PATCH v2 net-next] pds_core: remove redundant pci_clear

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date: Thu, 17 Aug 2023 10:57:09 +0800
From: Yu Liao <liaoyu15@...wei.com>
To: <netdev@...r.kernel.org>, <davem@...emloft.net>, <edumazet@...gle.com>,
	<kuba@...nel.org>, <pabeni@...hat.com>, <leon@...nel.org>,
	<shannon.nelson@....com>
CC: <liaoyu15@...wei.com>, <liwei391@...wei.com>
Subject: [PATCH v2 net-next] pds_core: remove redundant pci_clear_master()

do_pci_disable_device() disable PCI bus-mastering as following:
static void do_pci_disable_device(struct pci_dev *dev)
{
		u16 pci_command;

		pci_read_config_word(dev, PCI_COMMAND, &pci_command);
		if (pci_command & PCI_COMMAND_MASTER) {
				pci_command &= ~PCI_COMMAND_MASTER;
				pci_write_config_word(dev, PCI_COMMAND, pci_command);
		}

		pcibios_disable_device(dev);
}
And pci_disable_device() sets dev->is_busmaster to 0.

pci_enable_device() is called only once before calling to
pci_disable_device() and such pci_clear_master() is not needed. So remove
redundant pci_clear_master().

Also rename goto label 'err_out_clear_master' to 'err_out_disable_device'.

Signed-off-by: Yu Liao <liaoyu15@...wei.com>
---
v1 -> v2:
- add explanation why pci_disable_device() disables PCI bus-mastering
- rename goto label 'err_out_clear_master' to 'err_out_disable_device' 
---
 drivers/net/ethernet/amd/pds_core/main.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/amd/pds_core/main.c b/drivers/net/ethernet/amd/pds_core/main.c
index 672757932246..3a45bf474a19 100644
--- a/drivers/net/ethernet/amd/pds_core/main.c
+++ b/drivers/net/ethernet/amd/pds_core/main.c
@@ -367,14 +367,13 @@ static int pdsc_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 		err = pdsc_init_vf(pdsc);
 	if (err) {
 		dev_err(dev, "Cannot init device: %pe\n", ERR_PTR(err));
-		goto err_out_clear_master;
+		goto err_out_disable_device;
 	}
 
 	clear_bit(PDSC_S_INITING_DRIVER, &pdsc->state);
 	return 0;
 
-err_out_clear_master:
-	pci_clear_master(pdev);
+err_out_disable_device:
 	pci_disable_device(pdev);
 err_out_free_ida:
 	ida_free(&pdsc_ida, pdsc->uid);
@@ -439,7 +438,6 @@ static void pdsc_remove(struct pci_dev *pdev)
 		pci_release_regions(pdev);
 	}
 
-	pci_clear_master(pdev);
 	pci_disable_device(pdev);
 
 	ida_free(&pdsc_ida, pdsc->uid);
-- 
2.25.1